voltage multiplier bath

I saw the voltage multiplier Instructablehttps://www.instructables.com/id/High-Voltage-Multiplier/and I'm wondering if it's necessary to put it in oil.My capacitors would be severely under volted (that should be a word, the past tense of volt, LOL) and the diodes wouldn't even be challenged.

Topic by guyfrom7up   |  last reply



How to make a voltage multiplier?

I need to make a voltage multiplier that is cheap and easy to make and can get up to 20 times the input voltage(12 volts).  Its for an electric car design.  Can anyone help?

Question by Kalrag   |  last reply


Voltage multiplier and magnetic force?

Does magnetic force affect how much energy is multiplied by per section in a voltage multiplier like the one in this instructables: https://www.instructables.com/id/Build-a-Variable-High-Voltage-Power-Supply/ ? I was thinking of making this multiplier and to make it a bit more variable to make a voltage multiplier (electro-magnets around the capacitors) like the ac voltage muliplier on sparkbandbuzz.com

Question by pmk222   |  last reply


how do i build a voltage multiplier for changing 6 volts to 12 volts using diodes and capasitors?

Hi, since my last question failed miserable resulting in me wasting a bunch of good dollars on a useless , and at the time what was described as a "voltage multiplier", uln2003an darlington transitor array which doent seem to do anything like i was told, i am going oldschool and building a voltage multiplier so i can switch a 12v relay card from here, to power 2 motors via remote control using a 9 amp 12 volt current (10 bats X 1.2v X 3A )X 3 sets in paralell , for my r/c tank which i have used a receiver from a toy car which i have increased its remote control signal to up to 100m away (its a 40mhz remote from china nothing special). anyway i am trying to aquire a 12 volt current ( any amperage above what seems to be less that 5 ma according to the relay cards description) from my receiver that gives me 6 volts 700ma from the motor and 4 volts 900ma for the servo. recently i lost a diode for one of the 4 relay cards i am using so i sent my mother to buy me a uln2003an from jaycar and a single 1n4148 diode from jaycar as well, somehow she was tricked into buying a 100 bulk pack (wich she payed twice for despite getting only 1 bulk pack) but did get me the diode i needed for the relay to work without blowing the "on " led rendeing the relay for somereason inoperable. i have 99 1n4148 diodes now and i want to know if i can make these into a voltage multiplier for the relay to get turned on at 12 volts, using capasitors as well, i know it can be doen, i just dont know what kind of capastor to use or how to assemble it once i have the capasitor. please help em i have een stuck with this for ages and the answer is no i dont know how to use a transistor to switch the relay all i see is 4 ports 12v in 12 v out (for switching relay on) and the switcing part wich is conected to relay contacts http://www.jaycar.com.au/productView.asp?ID=ZR1105&keywords;=1n4148&form;=KEYWORD http://www.jaycar.com.au/productView.asp?ID=KC5434&keywords;=relay+kit&form;=KEYWORD links to the diodes i have and the relay ard also heres the transistor i have http://www.jaycar.com.au/productView.asp?ID=ZK8855&keywords;=uln2003&form;=KEYWORD despite description it says uln2003an on the chip

Question by oldmanbeefjerky   |  last reply


is it possible to make lightning gloves?

A friend of mine is offering me big bucks if i build him  a pair of lightning gloves which would shoot large sparks or lightning from one glove to the other. now because ive never built a voltage multiplier befor ei would like to know if theres any problems with my idea which is i get a  small 12v battery pack for racing car i connect that bttery (with a resistor ) to a transformer i then make a voltage multiplier with hv capasitors and diodes to multiply the voltage until a certain voltage is obtained. however i do not know how hoigh the voltage should be so that it is not lethal, but can jump at least one meter from one glove to the other. also as a safety precaution a large copper wire suit should be worn which me and my friend used on my uncles high voltage vandegraf generator whish shot 20m lighnting at us in our loighting suits ontop of our diving suits , and we never felt a thing. anyways, can you please tell e the specs of everything i will need to acomplish my mission?

Question by oldmanbeefjerky   |  last reply


How can I remove the diodes from a modern television flyback transformer?

I need high voltage diodes for a voltage multiplier that I am currently building, however, there is no way that my parents will let me buy any. Therefore, I think that the best place to get some would be a modern television flyback transformer. I have many of them and they are easy to find. I do not care about the rest of the transformer. The primary and secondary windings along with the plastic case will all be discarded. Unfortunately, my attempts with a dremel have all failed. What can I do?

Question by Xellers   |  last reply


What type of capacitors for Voltage Multiplier Circuit?

I want to make a voltage mutiplier circuit to get 30kV+ DC from 12kV AC, I'm not sure what type of capacitors to get or diodes. Also how many times does it multiply the voltage, for each set of 2 diodes and 2 capacitors

Question by JunaidA44   |  last reply


Coilgun, Marx Generator or Voltage Multiplier

I am building a coilgun and I have constructed a coil with several thousand turns, an ohm meter measures its resistance at 300 ohms, so I am having trouble powering it, I ran 240v through it and got nothing. According to my calculations, I need to run 1000 volts at the minimum through the coil in order for it to work. From my research there are three ways to do that: 1)A really big transformer (sub optimal for many reasons) 2)A Marx Generator 3)or with a Voltage Multiplier. Now I realize that you are supposed to connect the voltage multiplier to the Marx Generator, but wouldn't it be easier to just to make more multiplier stages and remove the Marx Generator entirely? I've seen voltage multipliers go up to 15kv, which is more than enough.

Topic by geekman2   |  last reply


voltage multiplier for flourecent tube driver?

I have a flouro tube driver from an old scanner, when i put 12v dc it i get a nice tiny spark across the output wires now i want to make the spark BIGGER how could i do it with not many parts?

Question by The nerdling   |  last reply


Info about Cockroft-Walton generator (multiplier). Answered

I'm making Cockroft-Walton generators again after some time and some problems I had, and I would like to ask some questions I couldn't answer by myself so I don't end breaking this new one I'm making. Is it bad to run the multiplier with the sole intention of making arcs? Could the discharge end damaging the diodes? I've been running the ones I created with UF4007 diodes, which have a peak amperage of 30A, now I'm using two BA159 in series (so I can set the voltage up to 2kV), they have a peak amperage of 20A. If yes I guess there's no easy solution for this, other than to reduce the discharge current or get beefier diodes. Regarding to the previous question, does the whole capacitor array discharges when an arc strikes, or just the last/lasts one/ones? Thanks for your time.

Question by Victor805   |  last reply



Parts for a high voltage supply?

I am trying to make a power 100-200kv power supply. I plan to do this by putting the positive output of a 7.5 kv flyback transformer through a cockroft walton multiplier. I have never done something like this before, so I am not completely sure about everything. I plan to make the multiplier with 14-15 stages. I thought that it would be okay to use 10 kv DC 1000pf ceramic disk capacitors in the multiplier. One thing I'm not sure about though is whether or not the flyback outputs DC or AC electricity. I assume it is DC since the input is rectified, but if it still is producing AC then I should probably use 15-20kv rated caps. The main thing is that I don't know what diodes to use. I thought I would use 1N4007 or something similar but the peak reverse voltage is only 1 kv. Does anyone know what type of diode to use, and where to get it at a reasonable price (below $2 per unit preferably)? 

Question by Higgs Boson   |  last reply


Where can i find prints to a voltage multiplier for 9or 12 v?

I need to build a voltage multiplier for 9v to about 4kv

Question by tulavatalo   |  last reply


How do you remove the high voltage diode from inside of a modern television flyback transformer?

I recently acquired an AC flyback transformer from an old vacuum tube television. I am planning on making a voltage multiplier for it to achieve voltages of 100kV +. Unfortunately, there is absolutely no way that my parents will let me buy anything at this moment, so I need a source of high voltage diodes and capacitors. Luckily, I have a big bag of capacitors, but I have no high voltage diodes. I do, however, have a pile of modern television flyback transformers that have built in high voltage diode stacks inside of them. I am wondering if there is anyway for me to liberate them. I do not care about the rest of the transformer. The coils can be damaged beyond all hope or repair, as long as I get the diodes out. So far all of my attempts at dremeling the transformers have resulted in a big white puff of dust from the insulation inside of the transformer. Any help is appreciated - Thank you.

Question by Xellers   |  last reply


Micro High Voltage

I'm going to attempt to make a super micro tesla coil that is 100% contained (unless it runs off of like 12 volts dc, then I'll use a wallwart). Of course, one of the i biggest problem is the power supply. So this is what I'm asking, what's the best way of ramping up the voltage? A tiny toroid transformer? An inductor that gets pulsed? Voltage Multiplier? Something with static electricity? Some type of Inverter? Using Greinacher Cascades? A marx generator hybrid? Other stuff I havn't heard of?

Topic by guyfrom7up   |  last reply


Can someone share with me a schematic to multiply a dc source? That produces, obviously a higher, output. Answered

I have a bug zapping raquet and i would like to increase the voltage to create bigger spark gaps. Portability is key. Output in AC or DC doesnt matter to me, but I guess AC would get better arcs.

Question by blindpyro   |  last reply


Why not get high voltage by boosting 300V to say 2KV ?

Hi, I plan to build High Voltage of 4KV. The output current is very low (say 100uA). I intend to use this as focus voltage in a CRT application. Hence, I am exploring the ways to do so. I have seen people building high voltage (8-20KV) using transformer followed by voltage multipliers. Now a days, MOSFETs are available which can withstand voltage upto 4.5KV. So it should be possible to create boost converter which could boost 300V to 2KV. Then one can further boost the voltage using voltage multipliers. The input voltage of 300V is achieved by rectifying the line voltage of 220V/50Hz. Visiting internet, I do not see anybody doing so. Hence I wonder what could be wrong in doing something of this kind. Could somebody elaborate ? Regards, Hardeep

Question by hardeeps   |  last reply


How can I multiply/double (or just increase) voltage in a DV 5v curcuit ???

ok i have the following parts to ue for this: (all leftovers from former project..)  :) 1x mosfet IRF510 power transistor 5,6A 100V 9x 2N3904 amplifier transistors 40V 0,2 A .0.625 W ~16x 1uF capacitors 50V ~99x recifier diodes 1A 50V ~35x 2k resistors  0.25 W the idea is to charge a battery pack consisting of 4x 1,2-1,25V = 4,8-5V 3000mah AA nimh batteries using my 5v usb wall charger that has 1A output! i tried connecting the battery pack directly to + and - and 'i think' its starting to charge but after 1-2 hours at full rate (5v 1a) it should be at least 50% charged (3 hours would be full charge -> 5W x 3 = 15W), but if i connect them they last for about 2 -3 minutes and then empty again!! so after this im concerned that i might need at lest 6V-10V to achieve the desired effect !!  -> charge 15W NIMH batterpack with wall charger (nokia ac-60e.. 1-1,5A) i nless than 3 hours (as like a phone would need !!) therefore i need a cuirciut (ONLY DC) to double my 5V OUTPUT to 10V (yiou shouldnt apply more than twice the curent of a batter pack) or ideally 6-7 V but i dont know if thats possible without a swiching IC or more different resistors.. so just doubling would be nice at the moment!!  

Topic by sblocc10   |  last reply


Cockcroft–Walton High Voltage Power Supply

Greetings! I have wanted to begin experimenting with high voltages recently and have already collected a series of projects that I would like to conduct. The only issue is that of my high voltage power supply. I have not the funds or resources to buy into a NST or MOT system and ended up looking for alternatives. I at first tried the ignition coil route that ended in failure and have now moved on. My question is, will a Cockcroft–Walton generator be able to run say, a tesla coil, jacob's ladder, or even a farnsworth fusor given that the necessary voltage is outputted from the multiplier.  Kind of between a rock and a hard place here, Thanks anyway!

Topic by SidC1   |  last reply


How many farads do I need (capacitor)?

I'm making a voltage multiplier circuit which involves the use of diodes and capacitors but I'm not sure how many farads I'd need for the capacitors. The input voltage for the first stage is 12kV 30mA.

Question by JunaidA44   |  last reply


Help application note on for High voltage supply of 12kv, 6kv from 24V AC, 50

Dear forum members. I am looking for HV multiplier circuit that accept 24V AC, 50 Hz and convert it to two HV outputs 1) 6KV , 2 mA 2) 12 KV , 2mA Can anybody have such application details, or made by themselves, or any app note reference. OR anyone had instructables on this site. Please give me such details on my email id "bdmehta@yahooo.com Regards, Bharatkumar

Topic by bdmehta 


can I turn 2A into 5A? Answered

I am makinga hot wire foam cutter and using the hot wire foam calculator from Shawn James and it says that I need a supply of 7.5V 5A, but my transformer only gives 2 A. I've seen voltage multipliers and I don't know if there's a current multiplier. If so, please give me the instructions to make one.

Question by tgferreira184   |  last reply


how to convert High Voltage DC into AC without changing Voltage? DO CAPACITORS WORK ON HIGH FREQUENCY CURRENT? Answered

I want to build a Spark Gap Tesla Coil but the problem is that I am unable to find a neon sign transformer locally. so i decided to a voltage multiplier. But its output is DC which means that Capacitors (most probably) not work. so please can you tell me how to convert dc to ac without changing its voltage. ALSO, I was wondering whether a capacitor will work with high frequency flyback transformers or not. ????????????????????????????????

Question by SHREYANSH_HV   |  last reply


How do you build a small High voltage high frequency power supply? Answered

I need the plans/general guidance to build a high voltage/high frequency power supply like the one used here http://www.youtube.com/watch?v=hUQReIW8f1Q&feature=plcp  . He describes it as "A small ignition-coil, driven by a simple NE555-circuit feeds a 2-stage-multiplier. 12kV out...almost no current, but as you see: Enough to start a fire." Im not sure how to build that. 

Question by lug big lug   |  last reply


do capacitors like this work?

Do capacitors like these:http://cgi.ebay.com/20KV-1000PF-High-Voltage-Ceramic-Disc-Capacitors-Y5T_W0QQitemZ360099674640QQcmdZViewItemQQptZBI_Electronic_Components?hash=item360099674640&_trksid=p3286.c0.m14&_trkparms=66%3A2|65%3A15|39%3A1|240%3A1318work in applications like voltage multipliers, marx generators, etc. Or are they meant for something else? They seem like a really good deal and I just don't want to buy a ton of them to fail on me in like 2 seconds.

Topic by guyfrom7up   |  last reply


I want to increase my 4.5v DC to 9v DC (actually little above 9v. 10v will be good), so plz help me out for this...?

 and current 0.5Amp is required......hoping any voltage multiplier circuit can do it. plz help.  srrry bad English!!

Question by anuk07   |  last reply


easy way of converting dc into ac

Does anybody know of an cheap simple circuit, using only a few components, to convert dc into ac or pulsed dc? I'm going to be using a super capacitor that's rated for 2.5 volts and I want more out of it, so the output is going to be put through a voltage multiplier circuit.

Topic by guyfrom7up   |  last reply


How much Ampage (aprox) can you get out of a basic voltage doubler? Answered

What valus caps should I use? Is bigger better? (regerding the caps) Can you use electrolitic caps? Will a full-wave multiplier give more current then a half-wave? I'm looking at doubling 12V to aprox.24V for a fairly high ampage aplication (>4A) Can it be done? (I don't have a 1:2 transformer, and am unable to buy one) Thanks so much!!! Every and Any bit of help or advice is greatly apreaciated. Thanks again,                        Mike

Question by muttyfutty   |  last reply


Sensor Help with Arduino

Hi all! I need help with trying to figure out datasheets. I was digging through my electronics when I found and LM35 sensor. So I looked up the datasheet but I couldn't find out how to convert the analog output to a temperature. I found an i'ble on how to do it but I want to know how to find that information in the datasheet so that next time I get something I'll be able to do it myself. I looked at all the curves and none of them seemed to be temperature vs. voltage. I also looked through the whole first part and couldn't find the multiplier. Also does that multiplier change with the amount of voltage you supply the LM35 with? Say I use 5 volts. Will it give a different reading over 4.5 volts? There's so much technical and complicated data that I don't know what to look for. Here is the link to the datasheet http://www.ti.com/lit/ds/symlink/lm35.pdf Thanks!

Topic by HavocRC   |  last reply


how can you use a tetrode in a vttc? Answered

I have this ww2 nos 803 pentode tube that can be used as a tetrode tube. It has a 350 watt rating and i want to use it in  a class c armstrong oss. How would i do that, and what resistors should i use, the power supply is a 2kv voltage multiplier

Question by electricfan   |  last reply


Is there an inbuilt voltage doubler/tripler in Modern half-wave DC DST flyback or just a inbuilt diode?

Hi, I have dc half wave modern type DST flyback from a   computer  CRT and put out around 30kv. I wonder: Is there an inbuilt voltage doubler/tripler in  these modern half-wave DC DST flyback or just a inbuilt diode?  I became every confused from very contradiction   info.   Why I ask? I want to know as well as I would want to build a multiplier for the flyback.   I know mine isn't the old AC type but the DST should be a DC  pulsed ...The  flyback I have just  looks like these typoical modern DST ones here: http://www.imagebam.com/image/b88cbf268367234 . Your help would be tremendously relieving for me. I have been struggling to  find out  for a while now...  Thanks a lot

Question by leviterande   |  last reply


How to use an op-amp?

Hi, I've got an op-amp, the part number is OP07CP and I am trying to use it to amplify a voltage by around about 200 times. My set up is 6v going into a voltage divider with one resistor of 100ohm and a variable resistor of 10,000-50,000 ohm, so the output is 10mV-50mv. What I want to do is have the op-amp proportionally increase the voltage, so it goes to a voltage range of 1-5v, which an arduino can read. The power supply is  5v (from the arduino) and the powers both the voltage divider and the op-amp. For some reason, following the simple non-inverting op-amp configuration I just can't get it to work. Do I need a separate power source for the amp? I think it might have something to do with the fact that the amp's ground, input and negative are all just going to the arduino's ground. What can I do to fix it? If someone could help or even give me exact values and configurations of components that would be fantastic. I know that the amp and divider seem like a pointless complication if was just trying to measure the output of the variable resistor, but if you knew the greater extent of my project it would make more sense. Cheers

Question by makincoolstuff   |  last reply


Power Supply Question? Answered

I want to build a switching Power Supply, without the use of IC's with everything already inside. I only want to use op amps and passive components. Below are my goals on what to achieve. I would like to make this PSU current limited, or at least shut off when the current goes too high. I basically took the concept of the linear voltage regulator and expanded on it, turning it into a 'proof of concept' switchmode supply. Input Voltage range: . . . .7-24 Volts Voltage: . . . . . . . . . . . . . . 5-24 Volts Max Current: . . . . . . . . . .10 Amps Price: . . . . . . . . . . . . . . . . $5 -- $10         Instead of feeding a voltage reference into an op amp, I modulated it with a few components. (A triangle wave generator, and a array of resistors to lower the amplitude and introduce a DC bias.) The DC bias is controlled by the current protection module, which is simply an op-amp that reads the voltage on a small resistor and multiplies it by 5. This finalized current controlled, DC reference biased triangle wave is fed into a comparator, which will then switch a rather large MOSFET on and off at about 200 Hz, with varying PWM, depending on how much 'droop' there is on the output. Here is a rundown of what the components will do: OK, I refined my plan to this general specs: Input Voltage range: . . . .7-24 Volts Voltage: . . . . . . . . . . . . . . 5-12 Volts Max Current: . . . . . . . . . .10 Amps Price: . . . . . . . . . . . . . . . . $5 -- $10        I basically took the concept of the linear voltage regulator and expanded on it, turning it into a 'proof of concept' switchmode supply. I don't want to use any prebuilt chips where you have a magic black box with inductors, capacitors and resistors connected to it. I want this to be entirely raw, basic, cheap parts. Maybe later, I will replace many of the op amps with a single programmable chip (like an Atmega328P)         Instead of feeding a voltage reference into an op amp, I modulated it with a few components. (A triangle wave generator, and a array of resistors to lower the amplitude and introduce a DC bias.) The DC bias is controlled by the current protection module, which is simply an op-amp that reads the voltage on a small resistor and multiplies it by 5. This finalized current controlled, DC reference biased triangle wave is fed into a comparator, which will then switch a rather large MOSFET on and off at about 200 Hz, with varying PWM, depending on how much 'droop' there is on the output. Here is a rundown of what the components will do: Green field: This contains a voltage regulator which acts as both a 5V power source and a voltage reference. Not only will this module produce a 5V output, but also produce a triangle wave. Blue field: This module will be fed the triangle wave, decrease it's amplitude, and inject it with a bias voltage, controled by the current limiter (red field). Red field: This basic module simply measures current flowing through a 0.1 Ω resistor, and multiply that reading by a factor of 10, and inert it (the circuitry is probably wrong, and I am not sure how this will work, if it even will do what I want it to Will this work?) Yellow field: The final modulated triangle wave is then fed into the last comparator, which will switch a MOSFET on and off at a fixed frequency of 200Hz. The output of this last comparator is now PWM. As the output voltage sags, the pulse width will increase, and cause the final voltage to stabilize at either the peak value of the triangle wave (with little to no load), or near the bottom end of the wave (with a heavy load) ------------------------------------------------------------------------------------------------------------------------------------ My questions:  I try to run this in LTspice simulator but some reason the output of the last comparator is a distorted triangle wave. I think this has to do with my filtering capacitor and MOSFET gate capacitance. Can anyone give suggestions about this design?  I'm sure the current limiting function is not going to work as intended until I finalize it's design (I hope I don't need more than 4 op amps altogether, It would be nice to use a single chip I already have) Any suggestions? I might just omit this part entirely, as it is not necessary.

Question by -max-   |  last reply


ion ray gun

Remeber a while ago I said I wanted to make some cool high voltage weapon in the shape of a gun? Well I've dicided to make an ion ray gun! The only problem is that I don't want to pay for plans (that's just not right, half the time they probably jip you). The closest thing I've found is this:http://www.freeinfosociety.com/site.php?postnum=250but that doesn't help me with saftey procosions (sorry, having a bad spelling day).Basically I need help for the schematics and the safe way to build and handle one. I don't want a wimpy one either, I want a medium power one, like do stuff from 10-20 feet or something like that.Oh and if possible, skip extra circuits by using something like this:http://www.goldmine-elec-products.com/prodinfo.asp?number=G9695I also don't mind making voltage multiplier circuits.If everything works I'll make an instructable out of it!Oh, and tech-king, you can use the sign now.

Topic by guyfrom7up   |  last reply


PSU design (major revisions): Transformer calculations help?

Recently I have attempting to design a proper dual-rail power supply that will allow me to set a voltage as low as +-1V up to +-30V in 0.1V increments at (hopefully) 3 significant digits (at least for the lower voltage settings). Anyway, this supply is also going to be current limited to up to 5A,again, it can be set to just about anything. I plan on using an Arduino micro-controller to set the output. In order to do this, I plan on using the analogWrite functions, or better yet, a legit DAC. There will be 4 outputs from the Arduino that will set the power supply output by applying a 0-5V voltage on the input of the 2 current limits and 2 voltage sets. (one for the negative rail, one for the positive). However, I have kept running into the same problem: how do I plan on driving this linear power supply with up to 200W*? My first idea was to use a a MOT, due to their high-power capabilities, and re wind the secondary with the right number of turns to achieve this output. However, I have heard that these transformers are not optimal for continuous running due to their poor and cheap design. (losses are very high). My second idea was to search around for a 250VA transformer. However, even until now, the VA rating confuses me. How does VA compare to W? I know this has something to due with reactive power, real power, and apparent power. However, I have no intuition of any of these 'powers.' How would I go about calculating the correct size transformer for the job, also, I am going to assume this linear power supply has the properties of a resistive load, since it is rectified and smoothed with a filter capacitor, so practically nothing should react with the AC power. (unless there is something more to the full-bridge rectifier setup I am considering.) This is when I came across unwound toroidal cores found on eBay for $25, the perfect price range! However, this has raised more questions! to start off, beyond turns ratio, I do not know now many turns I need for the AC side of things. I know intuitively and from experience, mains-frequency transformers do not work with only one (or even few) winding(s). I think this has to do with saturation, but I'm no expert by any means. and the inductive reactance of the transformer's primary. How do I calculate losses, inductance, and other important parameters of a homemade transformer like this? Things get very nasty when I look back at rewinding an old transformer. Now I have all these questions about inductive reactance, power, currents, magnetic flux and saturation, but also, about determining the original power rating of something like a very old small welding transformer or one from a large 10A car-battery charger. Is it possible to approximate the power by measuring the dimensions of the core? How close will this approximation be?  After getting frustrated with this, I considered alternative approaches. What if I purchased 2 ~20V ~6A SMPS (switch mode power supplies) connected them in series, and connect the center tap of my linear supply to the joining point between the 2 SWPS's? Would this be unstable and be bad for the SMPS if a load was connected between the 'outputs' of this new center tapped supply? Would any sort of balancing be required? Also, a bigger problem includes how this will be connected to my linear PSU design. With a low voltage @ high currents, I would be wasting a LOT of power, power that has to be dissipated away from the transistors. This heat can approach 200W, which is company unreasonable! Anyway, I would them have to either a switching preregulator, or modify the SMPS's so the voltage can be controlled easily and varied between, say, 3V to 20V. absolute accuracy is not required, close enough, and rest of my PSU should handle it. This becomes seemingly impractical too, and many other considerations need to be made. What should I do? what are the calculations and factors I need to know? i do not have an LCR meter to measure inductance, so trial and error is out. Does anyone here have experience at this? Help would be greatly appreciated! *The 200W figure was calculated by taking 40V, (What I believe would be a safe to allow some slack for +-5V voltage drop across my 2 shunts and transistors) and multiplying it to 5A of current for the maximum power output. ------------------------------------------------------------------------------------------------------------------- I have added an image of my current design, and I have modularized it the best I could. The YELLOW is all my current power-management circuitry. Currently just a transformer with many taps, going to a currently-undesigned switch box that will change the voltage on the output, which is then rectified and enters a filtering capacitor, finally entering the circuit.  The GREEN field is the voltage set. It is the most major part of the PID feedback loop, along with the ORANGE field. It works simply by feeding a voltage to the positive of a op amp configured as a comparator, and with negative feedback from the output. It then outputs a signal to the transistor, turning it either more ON, or more OFF depending on how the output voltage compares to the +Vset. The negative portion is largely the same, but the input voltage needs to be inverted so the output voltage is set negative properly. I was not able to use less than 2 op amps for this portion, unfortunately. The ORANGE field is current set. It works by measuring the voltage drop across the shunt resistor, and outputting a unity voltage that is referenced to ground, instead of to the positive rail. (It took me forever to finalize and perfect that!!!) Anyway, this voltage is then fed into a op-amp configured as a comparator to drive the transistor. The BLUE field is my switching regulation topology, which is controlled by both the ORANGE and GREEN fields. Do you like my use of diodes as a super-simple voltage or current selection switch? the op amp that outputs a lower voltage is the one that gets 'listened to' by the transistors. This way, current and voltage mode enable properly. This does add a small problem when it comes to powering the op amps, all of them have to be powered off of slightly higher voltages to swing the full range due to the voltage drops of those diodes. In the PINK field is simply a single-transistor solution to a constant current load. This allows the regulator to be regulated even at very low voltage set levels. This is why I am able to achieve a +-0.5V on the output (at least within LTspice) Finally, and most unimportantly, the light PURPLE fields have a simple ultra high-gain difference amplifiers that will detect if the output current and current set are the same, and turn On or OFF the respective LEDs. The green LEDs are voltage-mode indicators, and the red LEDs are to show when current-limiting mode comes on.

Question by -max-   |  last reply


What power supply and wiring setup should I use for an LED lighting fixture? Answered

I'm trying to build a light from LEDs. I managed to pick up 40 Bright white LEDs for $4 and want to put them all together into one light fixture. I know a bit about electronics, but I'm stumped on what kind of power supply I should build and how I should wire them. They are 3V 20mA. When building it should I multiply the voltage or the amperage? And should I run them in series or parallel? Any help would be appreciated. And please don't just give a "Do this" answer. I'm looking for more of "Do this because this is how it works." Thank you.

Question by animomne   |  last reply


Power Electronics: power converter Answered

I have been running through example questions for an exam I have coming up; the following picture is a condensed version of half a page of working. My lecturer gave us the solutions and a few steps between beginning and end to get to the solution so we could work it out. However, as you can see the picture below I got 30.6A whereas she wrote 54.2 down. The problem is to "Find the maximum values of the average" (done this bit) "and rms thyristor currents for any firing angle, alpha.". The values of R and Vs are in the diagram. Alpha is assumed to be 0 since then the thyristors will conduct for the greatest possible length of time. I think she may have got to the end then forgotten to square root of Pi before multiplying Vm/2PiR by it. Does anyone agree?

Question by Jayefuu   |  last reply


Calculate capacitance across full wave bridge rectifier? Answered

OK,so I need an AC to DC converter.I used a 9 Volts transformer to convert 220VAC to 9VAC,then rectified it to 9VDC using a full wave bridge rectifier(IN4007).I need to know the value of capacitance which is to be connected to the 9 volt DC output(I heard somewhere that its got by multiplying the forward current*5 then dividing it by input voltage to the rectifier and the result is obtained in Farads........well I'm not sure if this is right and I need clarification).I've currently used a 1000uf capacitor and my multimeter shows the dc output from the bridge as 14 volts which is really confusing because before I used the capacitor it showed 9 volts.I really need a way to deal with capacitance.Pls do help me. I've added some pics(not much of help but.....)

Question by Adarsh_tronix   |  last reply


Supercapacitor for power supply design?

Hi I am new to electronics but I have studied the basics and the logic. I have 6 3000 farad supercapacitor from Maxwell(not the boost cap one) with a power rating of 3 watt- hour, so each capacitor holds about 10.8 kilo watts(3 watt x 3600 seconds= 10,800 watts). So I have been wanting to make a power supply out of these and two types have ran across my mind: 1. Turning them to a voltage multiplier type of circuit( so like a voltage multiplier but the capacitor is these capacitors). So I would have an output of 500 amperes(6 3000 farad capacitors in series would have a capacitance of 3000f/6=500f) and output voltage of 16.2 volts. For charging this power supply I will use a step down transformer connected to the mains with some circuit breaker, fuse, switch and ballast/ resistor at its input, the transformer will step it down to approximately 2 volts ac which then I will rectify with a bridge rectifier. 2. Putting them in parallel so I would have a total capacitance of 18,000 farad at 2.7 volts, and putting them in parallel with my power supply. So this works by charging the bank and the bank will discharge when fully charged. The power supply will be the same like the first design power supply. However this circuit seems very risky and I might need some feedbacks. For your information I live in Indonesia and the wall outlet have 220 volts with amperage of ~20 amperes So I have some questions which are: Q1. Which power supply design is more ideal in terms of safety and efficiency? And how can I improve? Q2. For power supply design 2, I believe I might need some "system" for timing the charge and discharge of the bank,what circuit or system should I use/ make? How about using relay? Or spark gap? Q3. What should I do to avoid explosion of capacitor in both power supply Q4. What components are recommended for the charging power supply and what diodes are recommended for the design one capacitor bank? I already have the thick wires necessary for this since i know both systems deliver huge amount of power. And please inform me if there is any mistake or anything wrong. Any input is very greatly appreciated, you don't meed to answer all question since i know is a lot and i don't want to waste anyone's precious time. Thank you so much for your time.

Question by dikap123   |  last reply


How to make power bank with 8 rechargable AA batteries?

I'm a nobody at electronics, electricals and stufs. well i have some rechargeable batteries for some reasons,. 2 of my friend has a portable power bank for their phone. then curiously thinking if i can make that kind of stuf.. (DIY),.. if it possible please help me make this... my AA batteries is 1.5V with 500mah of power if i'm right. , then multiply by 8 so that will be 12V with 4000mah of power? right?. then i want this to charge my phone... recently searching i need to drop the voltage to 5, because if not, my phone battery will or might explode., then my phone will be damaged?.. so i need to make a circuit,, then that my problem, i dont know any thing about resistors and things like LM317, just i don't know anything about that.. i need it be able to be recharge and charge my phone, so here's another question, expect the wee did make something like that, then how will i be able to charge it?, it's 12v right from the inside? right?.. that all, hope we can make something like this,, if there's a related post, which has been already answered, if this is not possible.. That all.. Advance Thanks for helps... 

Question by ZoneOne26   |  last reply


how do i make an ac current with a battery? Answered

Hi, i have searched over the internet many a time, looking for how to make pulsating dc or an ac current, however all my results end up with devices which use ac or pulsating dc, which is comming from some homemade ac-dc converter running of mains. now, i am trying to find out how i can use a aa battery to aquire an ac current, or pulsating dc current, preferebly using parts aquirable from a disposale camera. the reason i need ac or pulsating dc is so that i can build a voltage multiplier, and also a tazer. i have tried plasmanas instructable on making a worlds smallest shocker, but it just doesnt work, if you cant get the specific transistors and transformers only aquirable from polaroid brand disposable cameras. plus there are no details on where to buy the parts, or even their details, beyond resistance and capacitance values. the main thing though is that i need to make the pulsating dc or ac from a portable power supply, aka a battery, as i also wish to make a dc-dc boost converter to use on different components within my rc tank. please help, whoever can answer my question best will receive a " best answer"

Question by oldmanbeefjerky   |  last reply


How to make a lightweight 10kv 500 watt power supply?

I need to convert up to 500 watts of 12 volt to at least 10 kv. It's important that it has both +10kv and -10kv. Right now I'm thinking flyback converter driven by a 555 to 1000 volts then voltage multiplier to 16kv. It's important that it's light so I don't want a regular flyback transformer. I'm wondering how duty cycle effects a transformer. Does it effect it like it would with an inductor-based boost converter? If so, then according to this calculator http://www.ladyada.net/library/diyboostcalc.html I would need an 88% (88% high?) duty cycle to get 12 volts up to 100 volts with a boost converter. Does this mean with a 1-10 transformer I could get 1000 volts from 12 volts with an 88% duty cycle? If so, then I need a light weight 1-10 transformer. I'm thinking winding a toroidal transformer will be best? So I could get a ferrite toroid (I'm thinking material 61, size 114) and wind a 1-10 transformer, but I need to make sure it doesn't saturate. Do I find out the saturation just like I would an inductor in a boost converter? If so, then according to the same calculator, the higher the output current, the less henries I need. So that means if I don't draw enough power it will saturate? I'm probably going to use 25 khz, so according the the calculator, if it's 100 watts then I need a little over a 25 henry primary. But if I use 500 watts, then I only need a little over 5 henries? This doesn't seem right. Soooo according to this toroid winding calculator http://www.66pacific.com/calculators/toroid_calc.aspx with a material 61, size 114 toroid, I would need 2 primary turns if it was drawing a minimum of 100 watts (the lower inductance/higher current can't be right can it?) and then I would need 200 turns. Sooo my question are (haha) is this a good idea for a light weight high power hv power supply, if so are the similarities I'm assuming between boost and flyback converter correct, and if so, how many/how do I figure out how many windings I would need on each side of a toroidal transformer/ how do I figure out what inductance I need for the primary. I have pretty good experience making boost converters but I've never made anything hv. Very long question thank you this is for an ion thruster.   

Question by sk8aseth   |  last reply


500W electric scooter control and instrumentation with Arduino mega

1. Introduction DC 500W motor control with an Arduino mega to limit starting current and to vary the speed of the scooter. The battery is in 24V, 10A.h. The following table summarizes their characteristics: https://i58.servimg.com/u/f58/17/56/35/17/a014.jpg https://i58.servimg.com/u/f58/17/56/35/17/a111.jpg 2. Bibliography: Link download : sketch_escooter_feed_back_reel_V1.ino https://drive.google.com/file/d/0B_fB3GAsM02FSlRTWHdyRkhuUW8/view?usp=sharing escooter_ampli_SIMULINK.mdl https://drive.google.com/file/d/0B_fB3GAsM02FOW9OdmlhdDhJZGc/view?usp=sharing escooter feed back ISIS.DSN https://drive.google.com/file/d/0B_fB3GAsM02FOXdRWFN5OWRMQkE/view?usp=sharing youtube  :  "study trotinette electric e-scooter 100W et 350W, wiring"  youtube https://www.youtube.com/watch?v=QqJ2-YiE8Tg&index;=75&list;=PLfZunVn_gcq7EOurXuWU2sRFmh6CbiUiL Article: «Study of electric scooters 100W and 500W (Arduino), Revue 3EI 2017» Pdf? Book «I realize my electric vehicle» at DUNOD 3. Open loop program To test the programming, we simulate the program in ISIS, as can be seen in the following figure. In addition, we have an LCD display to display data (duty cycle corresponding to the PWM at 32Khz, motor current, motor voltage, action on the pushbuttons, 4 push buttons are used. BP1 to manually increment the duty cycle, BP2 decrement it. BP3 set the duty cycle to 0, corresponding to the brake contact. The speed of the motor is practically proportional to the duty cycle https://i58.servimg.com/u/f58/17/56/35/17/a211.jpg We made our own current amplifier called a step-down chopper but it is possible to buy a shield There are many cards for Arduino to control DC motors especially of low powers and also of great powers as can be observed on the following links.http://www.robotpower.com/products/MegaMotoPlus_info.html http://www.robotshop.com/en/dc-motor-driver-2-15a.html https://www.pololu.com/file/0J51/vnh3sp30.pdf https://i58.servimg.com/u/f58/17/56/35/17/a310.jpg But all these chopper shields measure the current internally but there is no current limitation. In order to have a current limitation, an analog current loop is required using specialized AOP or IC or a fast digital current loop. But what should be the value of the limitation current? The choice of the current value is normally for the 1-hour operation service in order to be able to carry out relatively long climbs without reaching the critical temperature of the engine. In our case, the limitation current must be Limiting motor = Power / Upper battery = 500W / 24V = 20A In addition, the power transistor of the chopper can only support 50A in our case. But in open loop, it has no current regulation, so as not to exceed the maximum current, a ramp of the duty cycle will be used. A 0.1 second interruption routine will be used to measure the voltage of the current (sample measurement, sample). This sampling time is arbitrary but does not allow to be faster than the rise time of the current because the electric time constant of the motor is L / R = 1.5 ms. Open loop operation with a 25.5s (8bit) ramp and 0.1s interrupt routine provides a good understanding of the operation of a DC motor drive. The display will only be done every 0.2s to have a stability of the digits on the screen. In addition, a digital filtering will be done on the current and the voltage on 4 values therefore on 0.4s. [b] Algo open loop [/b] Interrupt Routine All 0.1S Read voltage and current Loop loop (push button scan) If BP1 = 1 then increment PWM If BP2 = 1 then decrement PWM If BP3 = 1 then PWM = 0 Displaying variables every 0.2s Code: [Select] // include the library code: #include #include #include #define SERIAL_PORT_LOG_ENABLE 1 #define Led     13       // 13 for the yellow led on the map #define BP1     30       // 30 BP1 #define BP2     31       // 31 BP2           #define BP3     32       // 32 BP3 #define LEDV    33       // 33 led #define LEDJ    34       // 34 led #define LEDR    35       // 35 led #define relay   36       // 36 relay #define PWM10    10      //11   timer2    LiquidCrystal lcd(27, 28, 25, 24, 23, 22); // RS=12, Enable=11, D4=5, D5=4, D6= 3, D7=2, BPpoussoir=26 // Configuring variables unsigned   int UmoteurF = 0;  // variable to store the value coming from the sensor unsigned   int Umoteur = 0; unsigned   int Umoteur2 = 0; unsigned   int Umoteur3 = 0; unsigned   int Umoteur4 = 0; unsigned   int ImoteurF = 0;  unsigned   int Imoteur = 0; unsigned   int Imoteur2 = 0; unsigned   int Imoteur3 = 0; unsigned   int Imoteur4 = 0;            byte Rcy=0 ;    // 8bit duty cycle unsigned    int temps; // the setup function runs once when you press reset or power the board void setup() {   pinMode(Led, OUTPUT);   // Arduino card   pinMode(LEDV, OUTPUT);   pinMode(LEDR, OUTPUT);   pinMode(LEDJ, OUTPUT);   pinMode (PWM10,OUTPUT);     // Pin (10) output timer2   //  digitalWrite(LEDV,LOW);   Timer1.initialize(100000);         // initialize timer1, and set a 0,1 second period =>  100 000   Timer1.attachInterrupt(callback);  // attaches callback() as a timer overflow interrupt   lcd.begin(20, 4);    Serial1.begin(9600);   TCCR2B = (TCCR2B & 0b11111000) | 0x01;         //pin 10  32khz    http://playground.arduino.cc/Main/TimerPWMCheatsheet                                                   //http://www.pobot.org/Modifier-la-frequence-d-un-PWM.html   //   analogWriteResolution(bits)      https://www.arduino.cc/en/Reference/AnalogWriteResolution lcd.setCursor(0,1); lcd.print("Rcy"); lcd.setCursor(10,1); lcd.print("Um"); lcd.setCursor(5,1); lcd.print("Im"); lcd.setCursor(10,1); lcd.print("Um"); lcd.setCursor(20,1); // 4 lines display * 20 characters lcd.print("BP1+"); lcd.setCursor(25,1); lcd.print("BP2-"); lcd.setCursor(29,1); lcd.print("BP3=0"); } // Interruptions  tous les 0.1s void callback()  { temps++; //toogle state ledv for check   if ( digitalRead(LEDV)== 1 ) {digitalWrite(LEDV,LOW);}     else {digitalWrite(LEDV,HIGH);}     analogWrite(PWM10,Rcy);   // frequency Umoteur=analogRead(A0); Imoteur=analogRead(A1); Imoteur2=Imoteur; Imoteur3=Imoteur2; Imoteur4=Imoteur3; ImoteurF=(Imoteur4+Imoteur3+Imoteur2+Imoteur)/4 ; Umoteur2=Umoteur; Umoteur3=Umoteur2; Umoteur4=Umoteur3; UmoteurF=(Umoteur4+Umoteur3+Umoteur2+Umoteur)/4 ;   }// End routine // Loop corresponding to main function void loop() {    // BP + LED   if ((digitalRead(BP1))==1) {     lcd.setCursor(20,0);      // Column line     lcd.print("BP1");     digitalWrite(LEDR, LOW);        digitalWrite(LEDJ, LOW);     Rcy++;                        // PWM incrementation     if ( Rcy>254)  {Rcy=254;}     delay(100);               //8bits * 100ms = 25S increment 25ssecond slope     }        if ((digitalRead(BP2))==1) {     lcd.setCursor(20,0);     lcd.print("BP2");             Rcy--;      if ( Rcy<2)  {Rcy=2;}  // PWM almost at 0, engine stop         delay(100);      digitalWrite(LEDR, HIGH);     digitalWrite(LEDJ, HIGH);     }   if ((digitalRead(BP3))==1) {     lcd.setCursor(20,0);     lcd.print("BP3");      Rcy=2;               // PWM almost at 0, engine stop     } if (temps>=2)  { lcd.setCursor(0,0); lcd.print("                "); // Erase line lcd.setCursor(0,0);     lcd.print(Rcy); lcd.setCursor(5,0); ImoteurF=(ImoteurF)/20;     //resistance (5/1024)*(10/0.25ohm) si ACS712 66mV/A                            // For resistance 1ohm (ImoteurF) / 20; Simulation 5/25 lcd.print(ImoteurF); lcd.setCursor(10,0); UmoteurF=UmoteurF*10/38;                              //10/38   10/30 simula if (Umoteur>ImoteurF){UmoteurF=UmoteurF-ImoteurF;  }  //U-R*I lcd.print(UmoteurF); temps=0; }// End if time    } // End loop https://i58.servimg.com/u/f58/17/56/35/17/dsc_0614.jpg Since there is a limit of 9000 characters in the forum below Open loop program feature previous The interrupt routine lasts only 250 microseconds, the loop of the main program which scans the action of push buttons is 13micros and the display time of all data is 11ms. Thus, it is possible to improve the sampling period and thus the speed of the regulation of the current. The Arduino makes it possible to make the instrumentation of the scooter so to know the power, the consumption in Ah and Wh, to measure the speed, to know the consumption according to Wh / km, to measure the temperature of the engine, Have a safe operation. But for now we will see how to limit the current 4. Closed loop program, limited current control The sampling period will increase to 0.01 seconds (interrupt routine) If the current is less than the desired value, then the duty cycle can be increased or decreased to the desired value which is the setpoint. On the other hand, if the motor current is greater than the limiting value, there is a rapid decrease in the duty cycle. So as not to exceed the value of the duty cycle if it is saturated to 254 maximum and to the minimum value 6. Code: [Select] if (Imoteur<4000)                    // No current limitation at (20A * 10) * 20 = 4000   {if (consigne>Rcy)   {Rcy=Rcy+1;}   // Pwm ramp + 1 * 0.01second pure integrator    if (consigne    if ( Rcy>254)  {Rcy=254;}           // Limitation of duty cycle    analogWrite(PWM10,Rcy);   // Frequency 32kHz timer2}         } if (Imoteur>4000)  { Rcy=Rcy-5;              // No current filtering, to be faster                     if ( Rcy<6)  {Rcy=5;}       // Rcy is not signed, nor the PWM therefore Rcy minimum must not be less than 6                   analogWrite(PWM10,Rcy);   // Frequency 32kHz timer2}                        } 5. Closed Loop Program, Limited Current Control with Acceleration Handle An acceleration handle provides a 0.8V voltage when not operated and a 4.5V voltage when the handle is fully engaged. Instead of using pushbuttons to increase or decrease the speed setpoint, an acceleration handle will be used Code: [Select] Upoignee=analogRead(A3); // The relation in Upoign and the setpoint which corresponds to the duty cycle corresponds to if (Upoignee>100) { consigne=(Upoignee/2);     //0=a*200+b    et 255=a*800+b                      consigne= consigne-100;                   }                            else { consigne=0;   }               if (Upoignee<100) { consigne=0;  }     // redundancy     6. Temperature and safety program of the motor with the current measurement The outdoor temperature measurement can be easily performed by the LM35 component which charges 0.01V by degrees Celsius Code: [Select] temperature=analogRead(A2); //lm35 0.01V/°C temperature=temperature/2;       // Temperature coefficient lcd.setCursor(5,2); lcd.print("      "); lcd.setCursor(5,2); lcd.print(temperature);   // Display in ° C lcd.setCursor(9,2);      // Erasing secu display lcd.print("     ");   if (temperature>80 ) {lcd.setCursor(9,2);         // If motor external temperature is above 80 ° C                      lcd.print("secuT");                       Rcy=0;} In addition, thermal safety by measuring the motor current will be added. If the limitation current is greater than 10s then the motor will no longer be powered for 30s. A "secu" display will appear on the LCD display. This safety makes it possible to cut the motor on slope too high and when blocking the engine but it would be necessary to add the measurement of the speed in the latter case Code: [Select] if (timesecurite>=10000 ) {flagarret=1;      // If limitation current for a current of more than 10s                               timerepos=0;                               consigne=0;                               Rcy=0;                                 timesecurite=0;}       //   Then stop engine during a downtime    if (flagarret==1 ) {lcd.setCursor(9,2);         // If limiting current for a current of more than 20s                      lcd.print("secU");  }     //   Then stopping the motor for a stop time and display                                                     if (timerepos>=30000 &&  flagarret==1) {flagarret=0;                                           lcd.setCursor(9,2);      // After a rest time here of 30s                                            lcd.print("       ");   }   The display can be observed if the temperature is above 80 ° C https://i58.servimg.com/u/f58/17/56/35/17/a017.jpg Thermal safety by measuring the motor current (digital thermal relay) which allows to know the image of the internal temperature of the engine would be ideal. But for this, it is necessary to know well the thermal modeling of the motor. 7. Measurement of the energy capacity of the battery The energy capacity of a battery is in A.H, we will display the value in mA.H to have a high accuracy. The capacity will be in A.Second in the following equation. So to have in mA.H, it will be divided by capacity by3600. Capacity (A.s) n = I * Te + Cn-1 with Te = 0.01s and I multiplied by 10 So in the interrupt routine Code: [Select] capacity=ImoteurF+capacity ; And in the display Code: [Select] lcd.setCursor(0,3); // Display of energy capacity lcd.print("C mA.h="); capacity1=capacity/(18000);   //18000=3600*5  5=> Current measurement coefficient lcd.print(capacity1); To check a current of 10A with an adjustable resistor and after 30s, the capacity must be 83mA.H 8. Power and modeling with SIMULINK Modeling helps to understand the vehicle and its control. In addition, it is possible to compile the control part directly into the Arduino program from simulation under Simulink. But it will not be possible to simulate the instrumentation with the LCD display. In the following figure, we can observe the simulation of the programming of the chopper with the current limitation with Simulink. In the following figure, the green box shows the duty cycle control to vary the speed and the red border the current limitation. The controller of the control is here a simple integrator but it is possible to carry out a multitude of control. https://i58.servimg.com/u/f58/17/56/35/17/azub_c15.jpg In the previous figure, it can be observed that the current is well limited to 25A from 2s to 9.5s. Then, the current reaches 10.8A under established speed regime at 22.5km / h. The dynamics are similar to the tests carried out. With a slope of 5%, the cyclic ratio reaches only 100% as can be seen in the following figure. The speed will reach painfully 19km / h with a current of 24A and a motor power of 580W. See article: Study of electric scooters 100W and 500W (Arduino), 9. First conclusion It is easy to control a 500W DC motor with an Arduino and some components So repair many scooters that are in DC motors. But it takes some knowledge (automatic, engine) to know how to properly manage the engine and limit its current so as not to damage it The display of the speed, the distance, the operating time to know the Watt.km / km can also be realized with a menu 2. The .ino program as an attached file, But it is not possible to put an attached file in ISIS electronic labcenter? What is this forum? It would be desirable that the compiler could generate the.cof to debug in Isis and test the program line by line .... Arduino still has to make a lot of effort to be on the same level as other microcontrollers 10. speed measurement (tachometer) Velocity measurement is carried out using a hall effect sensor SS495 or A1324 which counts each revolution of the wheel. It is enough to enter the perimeter of the wheel of the scooter (130mm of radius therefore 0.816m in the case To have the speed, it is enough just to divide the number of turn of wheel on an arbitrary time of 1s to have a minimum speed of 0.81m / s therefore of 2.93 km / h. In addition, an average filter with 3 values will be used to display the speed. At 25km / h, there will be 8.5 laps. To count the turns, an external interrupt routine will be used on input INT0 21 of the mega card. http://www.locoduino.org/spip.php?article64 To simulate the speed, a pulse on input 21 will be used with a duty cycle of 10%. https://i58.servimg.com/u/f58/17/56/35/17/a018.jpg Code: [Select] void INT0b21() {   Tspeed++;   // External interruption to count the number of turns } // In the set up declare the interrupt routine when the 5V edge of the magnet detection is done   attachInterrupt(digitalPinToInterrupt(21), INT0b21, RISING );  // External interruption // In loop if (temps09>=5)  {        // 1 second loop lcd.setCursor(13,2);      // Erasing speed lcd.print("kph     "); lcd.setCursor(16,2); speed1=Tspeed*2937;      //1tour*816*3.6/1s=2.937km/h speed2=speed1;           //Tspeed (rate/seconde) speed3=speed2; speedF=(speed1+speed2+speed3)/3000;   // To put in kph lcd.print(speedF,1);    // Display to the nearest tenth Tspeed=0;   // Reset counter temps09=0;  //reset time } To improve the accuracy of the velocity measurement, it is possible that the sampling time of the velocity measurement is dependent on the velocity. For example: For speeds less than 10km / h sample at 1second, but above 10km / h sample at 2 seconds. 11. Distance measurement for autonomy The distance corresponds to the total number of turns of the wheel multiplied by the perimeter of the wheel. So do not set the number of turns to 0 for each sample. On the other hand, the reset of the distance will be done when pressing the reset of the Arduino Mega. The distance display will be displayed to the nearest second. At 32km / h, it will take 2 minutes to do 1km as can be seen in the following figure: https://i58.servimg.com/u/f58/17/56/35/17/a019.jpg Code: [Select] void INT0b21() {   Tspeed++;   // External interruption to count speed   nbrRate++; } lcd.setCursor(13,4);      lcd.print("km      ");  // distance=(nbrRate*816)/1000;  //distance m distance=distance/1000;  //distance km lcd.setCursor(15,4);      lcd.print(distance,1);  You can observe the electrical installation with the chopper, the arduino, and the display when the program is set up https://i58.servimg.com/u/f58/17/56/35/17/dsc_0613.jpg 12. Synthesis The RAM space is used only at 4% and ROM space at 3%, for an Arduino mega. So we could take an arduino a little smaller. But, there are 8 Lipo cells to make the 24V power supply to power the engine via the chopper. Therefore, the voltage measurement of each element will be on the Arduino with a JST connector. This measurement makes it possible to know if a cell with an internal resistance which begins to pose a problem and to know if the balancing of each cell has indeed been carried out. It is possible to switch to 36V with 12 cells also with the arduino mega without using an external shield that multiplex 24 analog inputs on input A0 It is possible to send all data to a smartphone via Bluetooth HC06 via pins 20, 21, RX1 and TX1. But the application under android realized under JAVA Studio can not be shared on this forum. This part will not be explained. After having made the instrumentation of this scooter, a study should be carried out on the precision of the measurements, it is possible to read "Instrumentation of a low-power electrical motor vehicle" eco marathon "type Revue 3EI N ° 81, July 2015 http://www.fichier-pdf.fr/2015/09/07/instrumentation-vehicule-faible-consommation-eco-marathon/

Topic by Iutgeiisoissons 


Ceiling fan generator mod to the max

I stubled upon several mods to convert a standard ceiling fan into a more or less usefull generator.So if you are looking to go this route then I might have some nice improvements that can be implemented.People like these mods for some weird reason, despite the fact that it requires quite a bit of extra work to make them weather proof.However, when it comes to the fundamentals then to me it looks like some folks out there are missing out.On the available power that is...Always the first step for a mod like this is to replace the induction ring with a lot of magnets.Second step usually is to remove a lot of the coils, especially the inner ring.Now, these two stator designs are common for fans with two speeds.Those with three or even reverse might have a different configuration!Lets start on the magnet part:The recommended way of placing the magnets is by creating an air gap as small as possible - makes sense.But then it is always the same amount of magnets as there is coils - and the spacing is also the same as for the coils.In the general generaotr design world this configuration is prefered as it allows for the best performance.If you dare to go a bit further and cosider how the magnets react to the stator configuration then you might want to consider a different option.You see, these two sets of coils for two different speeds mean just one thing:A different amount of poles is created, with the outer ring having more poles than the inner ring of coils.The core is split around the coils, not just to allow the windings to be made but also to provide independent paths for the magnetic field - resulting in the two pole configurations.Amounts differ by diameter, power level, manufacturer and so on.What is always the same is that the inner ring has less coils and that the outer segments of the poles created have even spacings.In the normal mods you see posted these gaps in the core for the outer ring are closed by inserting lamitaed pieces from some old transformer.And you end up with ONE usable coil configuration and ONE power output.The slightly advanced mod uses the inner coil to add some load depending on the speed to prevent spinning out of control in high winds.If you try a normal DC motor with permanent magnets than you will notice the strong binding forces, it is like the rotor sticks in certain places.The better ones use and uneven configuration to reduce this binding effect ;)In my mod the magnets are selected in size to almost be the same length as two stator poles next to each other.This allows for the best induction while still allowing "to experiment".Bringing the magnets and the coils into play...As said an exact match of the number of magnets to either coil ring is not ideal.The prefered option is to go somewhere in between.For example:Outer ring has 18 coils then the inner ring will have 9 coils - exactly half.360° divided by 15 make a nice 24 degress per magnet.But with 12 magnets you get an even 30°, which is far easier to deal with.16 magnets at 22.5° is another option.So, what does that exactly do for us?The bad thing is we get slightly less performance if you only see the standard mod with one coil ring.The good thing we get far lower binding forces and through that the thing will even spin in very light winds.Adding both coil rings with a suitable rectifier however results in a pulsing output of two sine waves.With just the rectifier we get a ripple that is easier to deal with through a capacitor.The extra power available is in the range of about 40% and make more than up for the "reduced" amount of magnets.Going the extra mile once more ;)Having created a much fancier ceiling fan mod now you might wonder if there is not a way to get even more out of it.And there is.For example by utilising a gear system or belt to get a far higher rotational speed on the generator than what the blades would provide, prefably then with quite big blades too and an automatic break for high wind conditions.With the reduced binding forces the generator will be happy to spin at quite high speeds in low winds.Downside is that you will need to build a far more sturdy bearing housing.In return though you get more stability and durability.You can do the math yourself based on the number of poles per ring and magnets to get the output frequency based on the RPM's.Perfect would now be to use a switch mode power supply configuration to directly transform the provided output into a stable DC per ring.And yes, it is possible to use mechanical systems to provide a fixed output speed from the blades to the generator - but way to complex and lossy!Lets do some lame math with no regards to realities:If the original fan would spin at 100 RPM at full speed than we could say our generator should provide the mains voltage at about 100 RPM.Keep in mind we utilise both coil rings and not just the high speed one!Geared and with the blades spinning at 100 RPM we might get as much as 1000V from this little generator....And even with the lower amount of magnets we migh see frequencies above the 500Hz range.The good thing now is that normal iron core transformers can still operate at these frequencies.A bit lossy in the upper range but acceptable for the purpose.Put simple: A 10 or 20:1 transformer per coil ring would provide us with a far more suitable output voltage and much higher amps.If you made it to here than you certainly wonder about other magnet configurations.Checking the stator configuration you will by now realise why I selected the magnet lenght accordingly.The magnets "activate" one coil after the other.The spacing between them means there is always some overlap where the magnets only cover one half of the stator for a coil.This is ok because we don't really have to worry about the resulting messy output.Ideally though you would want to have a magnet activate both coils, the inner and the outer at the same time.What we did though was to make sure that at no time more than ONE magnet fully covers more than ONE coil!It is the best option to cover both coil sets while minimising binding effects and increasing the avialable output.To go the last step you would need to invest a lot of time re-winding all coils :(You don't want to do this unless you have the means and no friends and family that might miss you for a few days....I found a far simpler way to change the coil configuration, although it is not as good a re-winding.So let's go full scale shall we?Ceiling fan reconfiguration!If you take the usual 18 to 9 configuration than one thing jumps to mind reight away: 3-phase power!Cutting the wire that goes from coil to coil might not always be possible and if it is then you need to know how to handle it.Magnet wire can be hard to solder.Burning the coating off results in corroded copper that is even harder to solder.If you are lucky though than a reall hot soldering irong will be able to melt the coating.The flux from the solder will start to cover the wire from the cut and the solder will follow.If not then using some fine sandpaper and time is the other option to remove the coating...Ok, you seperated all coil and have two wire ends per coil?I hope you did not cut off the ones going out to the actual connections to the outside world ;)Properly solder each wire end and take your time to check it is really proper and not just a few spots.Mark or number the coils on the rings!For the inner ring we have 9 but need only 3, so we start at one connection to the outside world and check if this connection is on the outside or inside of the coil.For this example I assume you picked the one that goes to the outside of the coil.Connect the inside wire to the outside wire of coil number 3, assuming we start with 1 here ;)From the inside wire of 3 you go to outside of 6 and the inside is you first new output connection.Do the same with the remaining 6 coils and where needed add the required output wire.It really helps to have wires with three different colors here, one color per new coil set.Note which color corresponds to to the three coils used!!!The outer ring with 18 coils is sightly different here.You see, we want a "flowing" magnetic field that makes best use of the new coil configuration!We can not simply bridge them in any way we feel like without considering how this might affect the electrical side of things.As we now take the approach of a three phase system it makes sense to use a more suitable magnet configuration as well.So before go to the outer ring of coils lets have a look of the best option for the magnets first:The stator packs are evenly spaced in our example and will alow us to use 18 magnets.This provides the best performance with the downside of a higher binding effect, but we need this configuration to get the best possible output.As said at the start I selected magnets that are just shy of being the same length as the corresponding stator segments.In a "free" setup these magnets would now be quite hard to place in a makeshift ring.Even harder in the original casing.A 3D printer certainly helps but some common sense too ;)Wood is easy to work with and if you select the right stuff than making a suitable ring to hold your magnets and attach to the drive system metal parts is not too hard.Bar or brick type magnets can be quite easy be utilised on a wood setup :)The key is that you add Flux Capacitors - sorry couldn't help the reference to Marty....What I mean is to add some magnetic material between the north pole of one magnet and the south pole of the other.Lets say your magnets are 15mm long and have a spacing of 5mm.Then a little plate of 12mm would be next to perfect.This plate needs to connect the magnets on the backside, the side facing away from the coils.Use a dremel tool or what you have to first create slots for the metal strips or bars, then the same for the magnets.Glue in the metal first and once set add the magnet, making sure the always go north to south with their alignment.Ok, and what does this do for us?I hope you are not one of these persons who starts building while reading...What we created now is a shortcut for the magnetic forces.The field between the magnets is severly compromised in terms of being usable for the coils.We do get a much soother run though...I only did that to have some fun and check if you paid attention - sorry :(What we really want is an effect similar to what you see on a loadspeaker magnet that is still in its metal shielding.A ring magnet with one pole on the inside and one on the outside is used here.The shielding provides a path for the magnetic field that is not going through the speaker coil - hence the little air gap for the coil.If we do the same then our efficiency will be going up quite a bit.Take two identical steel parts, like some butter knifes, and prefarbly a force gauge.If you try to pull your magnet at a 90° angle from the blade you will get a certain reading for the required force to lift it off.Most people now think that this would be the max a magnet can hold.So take the other knife and place the magnet between them.If you pull the knife off with the gauge now the reading will be higher than what you get from just the magnet ;)Taking that to our model and keeping the field lines in mind we now know that we could even use slightly longer plates if our magnets happen to be a bit short :)Just place them right behind each magnet !Back to the outer ring of coils....With 18 magnets we get an even system for both coil rings.However we want to make sure that our output waves are syncronised and not at random order.We need to combine two coils to be back on a 9 coil configuration as on the inner ring.The other option is to provide two sets of outputs for outer ring, resulting in 3 3-phase outputs.Both have their pros and cons....But if you check the 18 magnet configuration ina ction over the coils it becomes clear that combining two coils the usual way is possible but also that our inner ring does not get a proper north south action from the magnets!Only the outer coil ring works properly!For the inner ring we never get only a north south combo, instead a lot of mixes.Did I mention to read first? ;)Of course we can only use 9 magnets in our configuration, but at least I did not traick you on their size....You see, we need to account for the fact that the coils are not just evenly spaced but also that all configurations in terms of coils to stator pack are doubles or halfs.Makes a lot more sense if you know how these asyncronous motors work :)With 9 magnets we actually get both inner and outer ring coils activated properly.Plus we now have the benefit that there are always twoouter coils in sync with each other.Means apart from the same way you wired the inner ring you make this addition to the outer ring:"One" outer coil is created by going from one coilinner connection to the outer connection of the second after this, skipping one coil.The resulting output is again just 3 phases but with double the output voltage.The key is to again take notes of how you connect and wire the coils - and the colors used for the output wires!Let me give you an example for the correct order:I we take the number 1 coil on the inner ring then coils number 1 and 18 would be next to it on the outer ring.You want to combine 1 and 3, 2 and 4, 5 and 7,....And you want the resulting three coil packs and wires colores to correspond to the inner coils in the same order!That is true for the always same way of combining coils from the inner to outer connection - or the other way around but never mixed!Ok, we have done the magnets and the coil configuration now properly, no jokes this time!With two simple 3-phase rectifiers we get two DC outputs that can be combined or used seperately.As we end up with roughly double the output voltage on one output but all coils are the same it makes sense to treat them independly.For those who wonder why:If you add a load than one coil system would take a higher loading of it.Meaning while one coil set is stll fine the other will already start to overheat - if the load is too great.So we use two rectifiers with some filtering.In the basic form just a really big electrolytic capacitor of suitable voltage or a full LC filer system with multiple stages.Either way we can now utilise some better DC-DC converters to get going.Considering the equal max watss the coil rings can handle it make sense to include some current limiting.A good converter will provide this option.Both converters can now set to the desiered output or with some added protection diodes and adjusted properly to the same voltage combined for just one DC output.Compared to the standard mod of removing coils and bridgning stator packs the resulting output power in overall Watt will now be about 40-60% higher - depending on the model and quality of parts.Special words of wisdom:Consider the orignal max speed of the fan when used as intendet - see this as a theoretical max output that equals your mains voltage.Just ignore losses and such things - better to be safe than sorry.It becomes clear that it quite possible that your output will be far higher than mains voltage and that you need use transformers for the two 3-phase systems so you can use standard DC-DC converters, which have a max input voltage of around 50V only.This means your converter must be able to handle the higher amps!The fan might have only used 100W or less than 500mA but at high speeds and a ratios of lets say 10 to 1 for the gearing high wind speeds might get it up to over 5 amps on the transformer outputs.Please do the math first for your gear system in relation to the max wind speeds you want to use with your blades!If in doubt use a converter that has some reserves to offer, especially if you aim to charge batteries as quickly as possible.The most vital part however is to ensure that all previously cut wires are isulated properly!!!Magnet wire of the standard kind is good for about 1000V max, so don't drive it higher!Heat shrink with a hot glue liner is prefered but hard to apply in these thight spaces.Since nothing moves consider using long enough wires for your connections so you have enough space to solder without affecting the heat shrink tubes.Liquid insulation or rubber is the last option and should only be used to finalside the heat shrink security measures.Best option once all is confirmed to be working fine would be to make a custom mold and to fully enclose the staotr pack and wires with casting resin or an insulating casting mix.Make sure to keep the output wirese free at the their ends ;)What if I don't want to build a complicated three phase rectifier and just use a single phase system as it was?Firstly chances are your coils are already connected in a three phase configuration, just all in series.But working out a suitable magnet configuration to suit this is much harder if you want to use both sets of coils.In a series configuration like the original you also have to accept the losses from these connected coils.The higher the overall resistance the lower the possible output ;)Main problem however is to get the magnet working properly.The standard 9 or here even 18 magnet configurations still works, especially with the added shielding from behind.But the coils also produce a magnetic field, which grows with the load.Means that an top of all you also have the coils working against the magnets and create even higher losses.Explains why the simple folks prefer not use the inner coil set if they go with a single phase system.So either accept the losses and just use the outer coils or do it fully and get far mor output.And by the way: a 3-phase rectifier modlue is only a few cents more than a standard bridge rectifier ;)Ok, and why do I bother to write all this?People like to tinker but most don't really invent.Following some simple instructions is easy, trying to work it yourself much harder.The reward however is that you actually start to know what you are doing :)And what works for a ceiling fan can be used for these ring style washing machine motors too ;)Anyways...We need to get back our roots.Start thinking for ourself again, work things out instead of just looking them up.If people would be aware that a simple ceiling fan could provide about 3 times the output power of its rated installation value instead of only just about half......Super strong magnets allow real output even without re.winding all coils.And what works here works for other things too.We only learned to use magnets in a striaght way because we can not bend them.But we can bed the magnetic field lines to our advantage!The simple shielding used in this mod is nothing more than a shortcut to enhance the field strenght where it is is needed.By a simple coil modification we basically bet two electrical generators for the price and size of one.Apart from stating how easy it would be to place multiple stators and magnet rings into one generator the magnets itself also allow for even more output.If you ever played with hook magnets or speaker magnets then you know how much stronger they are compared to just the magnet once they seperate after hours of fun for you.Imagine you would replace the single bar magnet with two block magnets that are joined by a magnetic shunt like out simple shielding before.If the magnet blocks now would have a slightly smaller footprint than your individual poles:Imagine you create a hlaf ring shaped magnetic connection between the two blocks that also goes aruond the outer perimeter up to the outside of the magnets surface?I mean the surface facing the stator poles?Damn your imagination is good, yout it right away!Of course we would then have a magnet that allpies its full strength focussed onto each pole of a coil!And of course the resulting field would be far stronger than just using the magnet blocks itself and still significantly higher than just adding a shielding or connection between them.The affect of the next coil coming is also drastically reduced, which in return also increases the efficiency.In terms of numbers:If a fixed neodymium magnet would provide us 100$ field strength as the base point with no shielding (just the magnet blocks alone);A fully shielded and connected system, like in a hook magnet combined with a U-style magnet, would reach above 400% here.....Adding witchcraft to the mix ;)Although I know better I just assume some of you have now a working double-three-phase-ceiling-fan-generator.And that would mean you also have some fans to spare from your long experiments.Modern ignition coils seem to have nothing in common with our ceiling fan or resulting generator.So why do I try to use them anyway?For the ignition only one polarity is prefered so the spark works and travels as intendet.Means the "wasted" energy from the othe half of the pulse seems to be lost.The electronics do a lot here but magnets too ;)The core of the coil has magents at either end, turning it into one long magnet that still has the right properties to act as high voltage transformer system with the coils.The coil appear to be pre-loaded and with the ignition pulse it has to overcome the magnetic field pre-set by the magnets.And when the electrical impulse is off the same magnets also accelerated and increase the resulting fall back impulse - which provides the spark.Unless you have a suitable laser cutter or simlar cutting tech available somehow it will be hard to modify the metal plates of the stator.But if you could...Imagine you could add magnet inside the plates that are inside a coil.The same pre-loading would happen.Does not really help in terms of adding outpur as our rectifier would suffer badly here.It does give ideas though...Shielding works fine for the magnets, same for field shaping.Electromagnets use the same techniques...So why not use some leftlever transformer cores to add more "shortcuts" for the coils?Strips of transformer core sheets added either side of the coils increase their field strenght and result in better output!Three packs either side of the stator pack are usually no problem.Now take your leftovers and do a standard mod.Compare the max output on the same windmill with what you get from my mod(s).The only real magic I used here is that I actually bothered to combine multiple and already used methods to drastically increase the available output of an otherwise utterly useless generator mod ;)Warnings:If you take the above mods serious and to the their extreme than it is imperative to make sure you have safety measures in place!Assume the lowest rating for the magnet wire and if in doubt stick with a max output voltage of 800V.These mods are potentially lethal if you don't follow what is common sense to everyone dealing with high voltages for a living!Most people will start without any gearing or belts and use the wind directly.Even here it is easy to get far higher RPM than what the thing ever did under your ceiling.Without some fixes you will need transformers to reduce the output voltage accordingly.Only other option is to limit the max speed to what your DC-DC converter can handle.Making mistakes with mangets can cost you a lot of time and work, make sure to mark their poles somehow to prevent putting them in wrong.If in doubt then double check!Always keep in mind what the magnet wires and your connections can handle!You don't want any arcs or overheating.Some added electronics to monitor wind speed, rpm's, load and temperature of the coils can turn out vital once you upscale.Before letting your new generator do its thing make sure you tested all to the max!Use a drill or so to speed it up and check the limit regulation for the converters.Measure the actual volts and amps going through your coil sets at assumed max speed and max load.Monitor the coil temp while doing so to ensure nothing is out of limit!You are kidding me here right?A scrap ceiling fan shall provide more output as a wind generator than what was used to spin it as a fan?And of course I need not one but two 3-phse transformers...Pretty clear it is all a fake because nobody could replicate any of it unless limited to what the converters can handle...Didn't I say to think outside normal restraints already?A single phase transformer uses two coils in the most basic configuration.For example one side for 240V and te other for 12V.But some of them are more efficient than other ;)A 3-phase transformer uses 6 coils, two for each phase.And there are plenty of standrad transformer cores out there that would allow us to use this configuration.The worst being the MOT, or microwave oven transformer.Very lossy for a reason but good as an example as these have three core stems ;)Now that you see that you will that a lot more transformers actually allow you to replace the two coils with 6 ;)Ok, but why not use a rectifier first and not use a transformer or two at all?The resulting output voltage will without a gear REDUCTION be much higher than what a cheap DC-DC converter can handle.And at such speeds the effiency would be very bad too.You would need huge capacitors of good quality to deal with the now more impulse like output.And considering the primary side of the transformer does not require anything thicker than the wire on the coils of the fan...Not hard at all to find some suitable tansformers to salvage - or to use some nice ring transformers ;)No kidding around, just facts and possible options you might want to explore.Does that now mean I get free energy?Sure, if you mean you get the free nergy from the energy of the wind at no cost.No if you think a ceiling fan could ever power your house.Internal resistance, size and wire/connection properties set our limits.Not to mention that they are designed to be dirt cheap.If you are in a windy region and assume a realistic 300W minimum output from a 100W fan then adding more stage multiplies this.These fancy upright windmills are not just powerful but also would allow to use one modded fan either end.If big enough and with enough wind force throughout the year you could just add a second or third stage to ech end.With 3 on both ends the resulting output would then be suddenly 1.8kW per windmill....And all from scrap parts with only the costs for the magnets...No wind? Then use water....None of it? Get some greyhounds and build a big hamster wheel :)You get the general idea I hope...

Topic by Downunder35m   |  last reply