resistors and watts

I know how to use ohms law to calculate what size resistor I need but what I really need to know is how to tell/calculate what watt rating I need to use whether it be 1/4, 1/2, 1/8, 1,10 and so on.

Topic by pattyshaw 7 years ago  |  last reply 7 years ago


What do 1/4, 1/2, 1 or 5 watts values mean on a resistor? Answered

I know that this is such a basic question but what do those values mean when selecting a resistor? 

Question by blkhawk 7 years ago  |  last reply 2 years ago


What is a 1/4 watt resistor? Answered

Alright, So I know the basics about resistors and what-not, but as I was buying beginner supplies, I noticed there were resistors in OHMs and Watts, What's the difference between the two? And like, can the unit Watt be transfered into OHMs? And which one would I use when my general area of working would be around basic LED work and noob stuff like that xD?

Question by E D E N 9 years ago  |  last reply 2 months ago


using 1 watt LEDs with a 4017

I want to build a chaser type light array using a 4017 counter divider circuit, 555 timer and the ever popular 1 watt luxeon LEDs, but I don't think that the 4017, or the 555 can withstand the current that will be going through them. I know in most cases you can simply toss a heatsink on the component and it will be fine, but I don't know if this will work with the ICs. https://www.jameco.com/webapp/wcs/stores/servlet/ProductDisplay?langId=-1&storeId;=10001&catalogId;=10001&productId;=12749Here is the spec sheet for the 4017. Thanks

Topic by John Culbertson 11 years ago  |  last reply 11 years ago


1 watt Frequency Doubled Violet Laser

I want to make a 1 watt violet laser, by using a 1 watt 808 nm laser and channeling the laser through a KTP crystal. Judging from my humble knowledge of second harmonic generation, That should create a 1 watt violet laser beam. Correct?

Topic by Nexoid 8 years ago  |  last reply 8 years ago


How can you tell or measure how many watts a resistor can handle.? Answered

Let's say I salvage a few resistors from an old electronic, how can I tell if it's a 1/8 watt or 1/4 watt etc? I have a multimeter if need be.

Question by surlistyc 8 years ago  |  last reply 8 years ago


Can someone help me with a simple audio amplifier?

I need to build a simple audio amplifier for an mp3 device for my A levels, but i dont know which amplifier to use, i would like the amplifier to have a variable gain of zero to the maximum and i also have 2 0.5 watt 8 ohm speakers. I was going to use the simple amp from here, but i am not sure if i can get the full 1 watt from the speakers using that amplifier. Any help will be appreciated.

Question by COOL_Q 8 years ago  |  last reply 3 years ago


Can the wattage of a resistor be greater than used in an Instructable? Answered

I am working on a project that calls for 1/4 watt resistors. I only have 1/2 watt at the moment... Is it OK to use these for this project? Thanks!

Question by ElectroFlex 6 years ago  |  last reply 6 years ago


How to power 8ohm 1 watt speakers?

I'm working on a project for school that consists of a wireless speaker. They will be mono speakers.  I have an 8 ohm 1 watt round speaker. I would like to power these.  I've read on lm386 and tsa7052 ic to do this. For the wireless I was going to use dexdex's instructible bluetooth headset hack I'd like to power it all with a 9volt or a lithium hacked out of old product. Are there any things i should know for the amplifier in relation to the type of speaker i will be using?  Will i be able to power the bluetooth headset and the amplifier from the 9v? thanks for your time!

Question by williamhaze 6 years ago  |  last reply 6 years ago


resistor Q

I'm building an LED circuit and I have the right ohm but the W is 1/2 when 1/4 was calculated out?

Topic by mrshow555 11 years ago  |  last reply 11 years ago


Is it true? 2 watt led has 1 diode, and 3 watt led 2 diodes? Answered

Is it true? 2 watt led has 1 diode, and 3 watt led 2 diodes? or can a 3 watt 700ma have both?

Question by MistaMasta 6 years ago  |  last reply 6 years ago


Free Radio Berkeley ~1 watt PLL xmitter

Hiya, I was wondering if anyone here has put together the FRB "1 to 1.5 Watt No Tune PLL Transmitter/Exciter"?? I have some questions...

Topic by nak 12 years ago


Need a 30 watt "LASER"

Looking for an inexpensive laser cutting/engraving system. I will be taking it apart and  customizing it to fit onto another machine.  Currently, we have a rotating blade to cut sheets of material, but this set-up causes many issues.  A contact free solution would be best.  So I want to mount the laser carriage above the cutting area; the rest of the laser parts will be contained in a metal cabinet under the machine.  The laser would need to be able to travel 12-16 inches in 1-2 seconds and cut through 1-5 mil paper/poly material. I have a fair amount of experience with lasers, I have know how to sight them in and understand the technology.  We currently have 45, 100 and 400 watt galvo head lasers, as well as a 90 watt XY laser set-up. So, what website would you direct me to, to purchase an inexpensive laser system?

Topic by benjaminleebates 4 years ago  |  last reply 3 years ago


Home made led light with 5w phone charger watt usage?

I have a led bulb which is 5w and I also have a homemade light bulb powered by a phone charger say also 5w. Question is Am I really saving any energy by using a phone charger unit it states it uses 5w? am I using 5w while is plugged 5w or am I using mAX OF 5W OF IT? DOES IT ALSO use 5w when it is only plugged but not powering my led bulbs . bulbs 5v 1 amp, 50 leds. thanks in advance. Also do you know a way to make a water proof glue at home?

Question by celalboz 3 years ago  |  last reply 3 years ago


2 ohm 1/2 watt 5% Resistor - Replacement

I'm trying to find what 2 resistors I could use in parallel to replace a single 2 ohm 1/2 watt 5% resistor. E24 series. Red/Black/Gold/Gold Thanks,

Question by Howard_S 5 years ago  |  last reply 5 years ago


mission of sputnik 1

Russian technology satellite. One launch, 1957.10.04. Tikhonravov's 1.4 metric ton ISZ satellite was to have been launched by the new R-7 ICBM as the Soviet Union's first satellite, during the International Geophysical Year.    But it was not ready in time, so Korolev hurriedly developed Sputnik 1 as a replacement. It became the first artificial satellite of the earth. Sputnik 1 had 1 watt of power, producing an 0.4 second duration signal on the 7 and 15 m bands. Four antennae were deployed at 35 degree angles. Power was provided by three silver-zinc batteries. Thermo-regulation was by a ventilator. The 580 mm sphere had a mass of 83 kg and was made of highly polished Aluminum AMG6T alloy 2 mm thick. It was built without drawings due to the quick time schedule. Korolev was everywhere, supervising all aspects of its construction. It functioned for 21 days.      AKA: PS-1. Gross mass: 84 kg (185 lb). First date: 1957-10-04. Number: 1 .     the word sputnik is russian word for traveller

Topic by Waren-Neutron 8 years ago  |  last reply 8 years ago


if you have a 39ohm resistor at 1/8 watt how many ohm 1/4 watt resistor will work in its place?

I was looking for a chart or cross referance resistor chart with no luck

Question by oldgoat118 8 years ago  |  last reply 8 years ago


LED 3 Watt Testing

I recently purchased 13- 3 watt LED's.  I'm trying to establish a high out put LED light.  I also purchased a LED Driver Transformer 48 Watt 120 Volt to 12v DC 4 Amp. First I would like to test each LED using the same divider.  I'm thinking that if I create a voltage divider two 330 ohms to limit the current and reduce the voltage to about 6 volts that would allow me to test with the driver that I purchased.  Secondly, will this driver be enough to drive all my LED's and would I have to reduce the voltage down too since it appears to push out enough wattage and amperage for the total number LED's I'm putting together?   I'm building my circuit based on this video. http://www.youtube.com/watch?v=4qYZahe2s5o&NR;=1   Assistance would be greatly appreciated.  Regards,

Topic by lancruz 7 years ago  |  last reply 7 years ago


Testing 3 Watt LED's

I recently purchased 13- 3 watt LED's. I'm trying to establish a high out-put LED light. I also purchased a LED Driver Transformer 48 Watt 120 Volt to 12v DC 4 Amp. First I would like to test each LED using the same divider. I'm thinking that if I create a voltage divider two 330 ohms to limit the current and reduce the voltage to about 6 volts that would allow me to test with the driver that I purchased. Secondly, will this driver be enough to drive all my LED's and would I have to reduce the voltage down too since it appears to push out enough wattage and amperage for the total number LED's I'm putting together? I'm building my circuit based on this video. http://www.youtube.com/watch?v=4qYZahe2s5o&NR;=1 Link to website data of 3 Watt LED. http://ledsupply.com/indusstar-1up.php Assistance would be greatly appreciated. Regards, 

Topic by lancruz 7 years ago  |  last reply 7 years ago


Testing a 3 watt LED? Answered

I recently purchased 13- 3 watt LED's. I'm trying to establish a high out-put LED light. I also purchased a LED Driver Transformer 48 Watt 120 Volt to 12v DC 4 Amp. First I would like to test each LED using the same divider. I'm thinking that if I create a voltage divider two 330 ohms to limit the current and reduce the voltage to about 6 volts that would allow me to test with the driver that I purchased. Secondly, will this driver be enough to drive all my LED's and would I have to reduce the voltage down too since it appears to push out enough wattage and amperage for the total number LED's I'm putting together? I'm building my circuit based on this video. http://www.youtube.com/watch?v=4qYZahe2s5o&NR;=1 Link to website data of 3 Watt LED. http://ledsupply.com/indusstar-1up.php Assistance would be greatly appreciated. Regards, 

Question by lancruz 7 years ago  |  last reply 7 years ago


electrical safety question Answered

1) how many 100 watt equivalent bulbs can i safely run into a normal heavier guage orange household extension cord? 2) can it be unsafe to leave the extension cord plugged in and powering the safest number of light bulbs on for days and weeks at a time?

Question by hobbssamuelj 9 years ago  |  last reply 9 years ago


WickedLasers Unleashes 1w Blue Laser Upon the Masses, or All Your Lightsaber Dreams Have Been Fulfilled

The good folks at Wicked Lasers unveiled their latest handheld high power laser: the Spider III Pro Arctic packs a blistering 445nm, blue, 1W beam that can SET YOU ON FIYAH for a mere $197.97. Wait wasn't the last one like 2 grand? Yup. Go check it out yourself, the website is loading slowly, presumably trampled under cyber foot as loads of people go to drool and purchase theirs. I'll wait. ... Yeah, it is real. Yeah, I want one too. Lasting 2 hours on a single charge, and sporting a scifilicous anodized aircraft aluminum body, this beauty packs quite a punch, apparently it is capable of setting bare flesh on fire almost instantly. Ouch. Now I REALLY want one. Who needs a gun when the tactical laser will make any offender scream and run away?

Topic by KentsOkay 8 years ago  |  last reply 8 years ago


How much will it take to burn out a 1/8 watt 1 ohm resistor? (and capacitor question)

I love electronics, and pranks, so I want to rig some things to "fail" by releasing smoke, and I figured what better way than resistors? I was wondering though, if I get some 1/8th watt 1 ohm resistors, will I be able to burn them out with the voltage from say, a USB port, or a double a battery or two? I was also wondering, is there anywhere online I can get some electrolytic capacitors, not super tiny ones, but moderate size that are only a couple volts?

Question by XOIIO 6 years ago  |  last reply 6 years ago


Would I be able to put one 100 ohm 1/4 watt resistor in place of two 50 ohm 1/4 watt resistors? Answered

The attached picture explains my question a little better. Thank you guys!

Question by Jakester98 4 years ago  |  last reply 4 years ago


5 mm led's 8 LUMENS PER WATT!?!?!? [answered] Answered

Well i was thinking, 5mm LED's take about 1/10 of a watt, correct?  and from this calculator found out Cree 5mm led's are .806 lumen's. i assume they are 1 tenth of a watt. well, my calculator states they are 8 lumen's per watt (if i could run them at a watt.)  i figure they are 1/10 of a watt because because this 500 led light makes takes about 50W as in the video and led's give less than a lumen of light. so far, it seems leds just last long and emit blueish light. is incandescent light better? with 20 lumens per watt from halogen?

Question by -max- 7 years ago  |  last reply 7 years ago


8 Watt Guitar Amp Help

I've been fartin around with electric and acoustic guitars for about the past 5 years. Only now am i getting decent (by no means good, but better, i guess...). I've been wanting to make a small amp with a small speaker for some time now.I saw this circuit the other day. Its VERY simple.http://www.aaroncake.net/circuits/amp.aspIt says to reverse the values of R1 and R3 for use as a guitar amp. there's some other stuff too. I was going to see if i could pick the stuff up at radioshack tomorrow, and maybe make it an after-work project for the week. Maybe cut up some wood and make a nice box for it. 1)Do you think these parts would be available at radioshack? and what do i need to look for if i cant find the exact IC? 2)Any special soldering tips? 3)What kind of pot do i need to add, and where, for a volume knob?4)Is there any extra things you think that needs to be added?5)Are those triangle things grounds? as in 12v negative? And what about the other wire from the guitar? 6)Also, what ohmage speaker do i need to use? What am i looking for in a speaker?7)Will 8 AA batteries do the job?8)Do i need to add like a fuse or something somewhere? Going straight into the IC...i dont know. If anyone knows of simpler or better designs, let me know. I seem to really [insert proper four-letter word here] up electronic things. I think thats all the questions i have here. To respond you can just go like..1)i think that....like that. Hopefully that will make it easier to answer all my ignorant questions.Thank you!Jason(sorry if i seem like a a$$ here. Its 1:35am, I've been looking this stuff up for two hours, and i dont feel like i got any further....)And since i dont have a suitable picture, have yourself a look at my LEGO steam engine: (after the third try of trying to post the video with unsuccessful results, i realized that i was posting the embed code int eh URL place...need....sleep....)

Topic by John Smith 10 years ago  |  last reply 10 years ago


increasing wavelength?

Is it plausible to increase the wavelength of, say, infrared light? I have a 808 nm 1 watt laser and i am struggling with researching if it is plausible to do so, and if it is then how it would be accomplished?

Question by Nexoid 8 years ago  |  last reply 8 years ago


Suitable transistor or IC to run 1 Watt LED in low voltage? Answered

I want to run 4 x 1Watt LEDs from a 3.7V source (10000mAh). LED DC Forward Current: 350mA The purpose is to sue it with a motion sensor. Please suggest a transistor or IC with maximum efficiency. Update: I found that the "IRF 540" Mosfet is a good solution.

Question by shijilt 2 years ago  |  last reply 2 years ago


Run a few 1 watt LEDs using transistor from 3.7v ?

Hi , I want to control 5 X 1W leds using a LDR. It will be running on a 3.7v 4500mAh battery . I have the LDR circuit. The problem I face is , normal transistor are not capable of running 5W leds (1W X 5) , it just heats up. i tried some high power transistors , they seem to provide less voltage to the leds. I need a transistor , which can be used as a switch , it should work well in 3 v , should be able to handle max 5W. Any one have any idea ?

Question by shijilt 4 years ago  |  last reply 4 years ago


Resistors? Answered

I'm trying to do the evaporator workaround for the Ford Fusion. Instructions from this page say to use 37kOhm 1/8 watt resistor. No one has this. Can I use other wattage rated resistors such as 47 kOhm 1/2 or 1/4 watt ?

Question by DaleH48 2 years ago  |  last reply 2 years ago


What to do with a 45 watt solar panel?

I have 2 solar panels 1 is (15w) and the other is (30w) they both produce around 3 amps together in good wether Anyone have some good ideas on what to power with it. it is charging up a 17ah battery

Question by Daniel Deacon 7 years ago  |  last reply 6 years ago


Lens for FOCUSSING a 3 Watt LED upto 5 Meter Distance

I want to Lens to focus a 3 Watt LED for distance of 1 meter to 5 meter without diverging. The light must traverse as a beam upto distance of minimum 1 meter and maximum 5 meters.Can anyone suggest me the type of LENS and its details.

Question by aalishaan 2 months ago  |  last reply 2 months ago


LED Fixtures

I need instructions on how to construct an LED system with remotely located 1 watt fixtures with the furthest fixture being 50' from the power source I'll need to drive at least 10 of the 1 watt bulbs. Thanks for any help 

Topic by zappenfusen 9 years ago  |  last reply 9 years ago


Building 2 speakers and linking them to a home cinema amplifier, need some help

1. For one speaker I'm linking 1 8 Ohm 8 Watt and 1 8 Ohm 5 Watt speakers, should I link them in series or parallel? 2. Do the speakers need any additional amplifiers?

Question by ElectroHops 9 years ago  |  last reply 9 years ago


resistor parallel

Sir I need 100ohm 3 watt resistor but cannot find it in market, in market I find 100ohm 1watt resistor ,plz tell me how I acquire (100ohm 3 watt resistor) value. can I parallel three 100ohm 1 watt resistor to get my value

Question by robinhoodxx 4 years ago  |  last reply 4 years ago


50 watt electric and bass guitar amp?

Good day to all, i'm new to this site hope i can gain more knowledge in electronics here, since i have been doing alot of programming lately.. i am planning to build my first higher wattage amplifier for both guitar and bass, i already have built smokey amp and its other cousins like the ruby amp and some guitar effects. i will build the two amps simultaneously and put  it in one housing.. the speakers will be separated and also the circuits and all.. does any one have schematics for this kind of amplifiers?? it should bea solid state amplifier, because its hard to find tubes here and also it is expensive.. correct me if i'm wrong 1. "instrument >>>preamp>>>poweramp>>>>speaker" ? 2. is it possible for example to use a smokey amp as the preamp section and connect it to a 50 watt power amp? 3. what type of speaker should i use for the guitar and for the bass? should it be a woofer or sub-woofer? coz i dont have a clue on speakers.. tanx in advance..

Question by VAustin89 7 years ago  |  last reply 6 years ago


Resistors are too warm

Hello,I am building a multi-touch surface using the FTIR method and after the surface is powered for about 10 minutes there is a heated smell in the room, I have noticed that the resistors are very warm and that a couple have started to brown or burn. I really need this table to be able to be safely powered at least 18 hours a day.Here are my specs:LED's:I am using 88 Infrared LED's (T 1 3/4 INFRARED LED, http://www.allelectronics.com/make-a-store/category/340250/LEDs/Infrared/1.html )--8 LED's per series--forward voltage of 1.5v --forward current of 100mAResistors:I am using 2, 10 ohm 1/4 watt resistors parallel (so 5 ohms) with each of the 11 series'Power Supply:The power supply output's 12 volts DC and 1.2 ampsWhen I calculate using http://led.linear1.org/led.wiz it says I only need 1ohm 1/4 watt resistors, I haven't tried this yet but it doesn't seem to me that this would rectify the situation. My guess was that I need 1 watt resistors, but the calculator didn't seem to agree.Any thoughts as to what my problem is? is it safe to go with 1 ohm 1/4 watt resistors? or do I need 1 watt resistors? Any help would be very appreciated, thank you!

Topic by hapticdata 10 years ago  |  last reply 10 years ago


mini laser driver for 1 w blue laser pointer?

Hi anyone here?  I need help with the construction of mini (using smd)  for 1 watt blue laser driver. I find it difficult to obtain the circuit for the driver. I would be grateful if anyone can help me. Thanks in advance. Tony1gunalan

Question by Tony1gunalan 6 years ago  |  last reply 6 years ago


How can I identify the power rating (wattage) of my scavenged resistors? Answered

I am currently making a mini guitar amplifier, from this instructable, https://www.instructables.com/id/Make-a-Sweet-Portable-Guitar-Amp/, and i need a 1kΩ resistor. I have accumulated a few components by de-soldering and scavenging parts from old, and broken electronic devices. When I found out i needed a 1kΩ resistor, I looked up the ring code for that value and scanned over my broken electronic circuit boards to see if i could find a match. Which i did, but i do not know how many watts the resistor is rated at. The resistor in question is no more than 3mm in length. I know that quite a lot of resistors are more like 5mm in length. Can you tell from the physical size what the resistor I have is?(I will include a couple of pictures)

Question by mdog93 8 years ago  |  last reply 8 years ago


How do I power 1 watt leds, can these not be hooked up straight to a power source with an appropriate resistor? Answered

I have on ebay a number of cheap 1 watt leds, please see the pictures below.  Some look like large LEDs with perhaps thicker then normal anode and cathode leads coming out of them, others look like they are surface mounted onto a circular, flower shaped circuit board with possible multiple soldering point to apply power.  I am hoping to power 24 of the 1 watt LEDs off a modified computer power supply (I use these for powering everything that needs a bit more amperage).  LEDs are Forward Voltage: 3.2V~3.4V  Forward current: 350mA.  In some of these adds they refer to them also being able to supply the driver, is this a term for a power supply?  I was planning on running it off the power supplies 5v out with an appropriate resistor.  The all share the same forward current, while the forward voltage varies from 300mA to 350 mA.  Can I treat these as regular LEDs, mind you they will get quite hot I assume, or am I missing something?

Question by iminthebathroom 8 years ago  |  last reply 8 years ago


inverter

I am making an inverter whivh converts 12 V dc to 230 V ac i am using 2 33 ohm resistor of 1 watt to connect the load on transformer whenever i switch on the ckt the 1 watt resistor are heating to much and multimeter does not show any voltage i am using 12 Volt dc 2.5AH battery as power supply what is the problem

Topic by AbhishekR2 4 years ago  |  last reply 4 years ago


Speaker and Amplifier Wiring Please Help!

As you can see I have a car amp and some speakers, can anyone with speaker or amp knowledge please tell me (or even better draw a diagram :D) of the best (most efficient / loudest) way to wire all these up, the specs are as follows… AMP 2/1 channel amplifier Max power – 400 watt 4 ohm stereo – 2 x 75 watts RMS 2 ohm stereo – 2 x 100 watts RMS ROUND SPEAKERS (midwoofers) 4 ohm 25 watt RECTANGE SPEAKERS (tweeters) 4 ohm 4 watt Thanks for your help! (P.S my plan is to build a portable sound system powered by a car battery)

Topic by superrob 7 years ago  |  last reply 7 years ago


How do I change Low current DC to high current DC?

Suppose I have a high voltage source of DC with fractional milliampere current.  How can I increase the current? I think Watts is fixed with respect to source. So, if there is 12000 Vdc at 1 milliampere (12 Watts??) I should, in theory, be able to get 12 Vdc @ 1 amp. Practicality aside, is this correct? Practicality engaged:  Is 12 Vdc at 1 amp possible, and how?  4 amps???   

Question by Walap42 6 years ago  |  last reply 6 years ago


LED run time computation?

If a cell of 10 volts were to operate on a joule thief circuit on 2 1-watt LEDs. How long will that last?

Question by ZjY 2 years ago  |  last reply 2 years ago


0. What is Current ? 1. What is Voltage? 2.What is Frequency?

My Dout is : 0. What is Current ? 1. What is Voltage? 2.What is Frequency? I know Definition. But i need practical example for this thing OK. So what is my dout is 1. When voltage increased current is also increased !      But in some case When voltage increased current decreased OR voltage decreased current increased. How it is possible Current is depend on voltage so When Voltage is zero then current is also zero only know For Example: When 100 Watt bulb receive high voltage then high electron will flow through tungsten of bulb then bulb will give high brightness ok Then same 100 Watt bulb receive low voltage then low amount of electron only flow through the bulb then bulb give low brightness This is the Rule or Nature So Current is depend on voltage only. Then how voltage decreased when current increased. This is my basic dout not only this and many dout about frequency also And Thank U for Replying ME. Thank U

Question by Xzyamaha 6 years ago  |  last reply 1 year ago


DC to DC Convertor?

Does anybody have a circuit that is able to turn solar power from a solar panel (preferably 1 watt) to make enough juice to recharge an iPad? The iPad requires 10 watts of power to charge. I wanted too use Adafruit's mintyboost but I don't think that has enough power to charge the iPad. Any suggestions?

Question by blinkyblinky 7 years ago  |  last reply 7 years ago


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 7 years ago  |  last reply 6 years ago


LEDs from ebay? Answered

Is ebay a reliable source of LEDs? I bought a 3 watt LED off there once (http://cgi.ebay.com.au/3-X-POCKET-LUXEON-3-WATT-LED-TORCH-FLASHLIGHT-LIGHT-3W-/320514643442) and it had kinda poor performance...but I don't know whether it was because the torch itself was poor or if the fact that buying it from ebay was what made it bad. Any how, I'm looking for a 1 - 3 watt LED, and a (narrow beam) lens for it, and was wondering where I could get it all for under $10 (AU). WOuld ebay be a reliable choice?

Question by .Unknown. 8 years ago  |  last reply 8 years ago


Help wiring an LED array

I'd like to buy some LEDs off ebay and build some LED arrays but I'm confused as to how to wire it. For example, lets say I have 100 watts of LEDs (aka 1 watt x 100 LEDs or 10 watts x 10 LEDs) as an extreme example and each LED has a max voltage of 12 volts. Then lets say I have a power supply that provides 100 watts at 12 volts. How would I wire it? I'm worried that if I hook it up, lots of LEDs will just burn out. Just help me understand what I need to watch out for here. I'm obviously a super novice. Have pity.

Topic by WillE2 4 years ago  |  last reply 4 years ago


Different collor high powered 3 watt led strings on one constant current power supply? Answered

Greets, Can i connect 3 different collored led strings to one constant current power supply? This is my power source, gives min 9v and a max of 48v @ 700mA Mean Well LPC-35-700 https://www.meanwell-web.com/product_info.php/products_id/LPC-35-700 My leds all 3 watt 6 x 630nm red - 2.5v/3v - 750mA 2 x 660nm deep red - 2.2v - 700mA 2 x 460nm blue - 3.4/4v - 750mA Can i create these string? 1 string with 6 x 630nm = 18v @ 700mA, should have no problem to run, right? 1 string with 2 x 660nm = 4.4v  (9v min from power) 9v - 4.4v = 4.6v / 0.7mA= 6.57 ohm resistor i should add to this string, correct? 1 string with 2 x 460nm = 6.8v (9v min from power) 9v - 6.8v = 2.2v / 0.7mA = 3.14ohm resistor i should add to this string, correct? Can my power supply handle this? Since it changes voltage. If i can use this, which watt resistors would i need? I would also for example like to add 1 potentiometer for the 460nm blue leds And add 1 potentiometer for the 660nm deep red leds Am i asking to much here or can this be done? Thnx JB

Question by MistaMasta 6 years ago  |  last reply 6 years ago