DC to DC UPS (Help!)

Hi i am trying to build a sort of DC TO DC ups for my modem/router, please look at the image attached for my project plan. I was able to find many charging circuits online but i cant understand what value relay and capacitor should be used. can any one help me with this project. Thanks in advance. http://i52.tinypic.com/v2v38n.jpg

Topic by spooge   |  last reply


dc inductor

Do inductors work with pulsed dc? like would they become more resistive with frequency? Or would they do nothing because it's not ac and the electrons can't "bump" into eachother.

Topic by guyfrom7up   |  last reply


DC transformer? Answered

Transformers work with AC power, but can you use pulsed DC power to run one?

Question by Jimmy Proton   |  last reply


AC or DC? Answered

Is there a way to tell if something i AC or DC power if you dont know, my multimeter will read ac on the dc setting and vice versa.

Question by Jimmy Proton   |  last reply


DC power + or -? Answered

I have looked at lots of Instructables and websites, but there is a 50/50 split that power flows positive to negative and negative to positive. Which is it? I use both, depending on the circuit I am building it is easier to build one way over the other (NPN and PNP Transistors usually) But I have heard that it used to be thought that positive flowed to negative but I have since heard that the new idea is that it flows negative to positive. I know that everything is supposed to flow from higher concentration (+) to lower (-) but we could have batteries labeled wrong so I don't know. Very confused.

Question by Electric Spectre1   |  last reply


DC motor

I had a 220v angle grinder. It was burnt. I take the rotor of the grinder out. Its completely fine. Now i make a DC motor using this rotor and magnets(for field current). My question is, how much maximum DC volts this motor can take to get the maximum RPM. Because the motor was 220v AC, Will it run on 220v DC?

Question by Shezi007   |  last reply


dc motors

Hi: Can anyone tell me why my 24volt dc motor which I just got rebuilt will only work on 12 volts and immediatly overheats and stops with 24 volts? Thanks, Royal

Topic by cra   |  last reply


DC Motor

Hi Guys, I have a 15.6 volt dc motor taken out of a handheld vacuum cleaner. is this suitable to use in a small wind generator as a project with my kids. when i attach it to a power drill and spin it from the shaft i dont seem to get any power generation. If i connect it to a 12v battery is spins real fast. any help would be appreciated sam

Question by sam301   |  last reply


Changing DC Circuit to Pulsed DC

I am interested in changing my fixed current DC circuit to pulsed to increase the brightness of my LEDs. I really have no direction when it comes to making this pulsed circuit. I have looked into precision full wave rectifiers that I think are what I would be looking for. I am not sure what type of pulse width I would want. The one that I think would be ideal would be a Mouser DF01M, I am not sure if a pulse width of 200 microseconds is fast enough.

Topic by JimmyWatson30   |  last reply


Changing DC Circuit to Pulsed DC

I am interested in changing my fixed current DC circuit to pulsed to increase the brightness of my LEDs. I really have no direction when it comes to making this pulsed circuit. I have looked into precision full wave rectifiers that I think are what I would be looking for. I am not sure what type of pulse width I would want. The one that I think would be ideal would be a Mouser DF01M, I am not sure if a pulse width of 200 microseconds is fast enough.

Topic by MarcusJubin   |  last reply


Desktop PC DC - DC UPS ?

This might sound stupid, but I was watching some guys build batteries to Electrical Cars using Laptop batteries like Tesla does (18650 battery Cells)  and I got thinking about creating an UPS for my PC. If Im not mistaken, most UPS convert AC to DC current and in a mains power loss they convert back DC to AC which is not very efficient I assume. So why not instead of going thru that process, why not power the PC components directly from the UPS in the event of a power loss or power supply failure?? My idea was to build a UPS that works completely on DC power, from its input to its output. So the PC power supply would charge it and the UPS would power the PC components in case of a power failure. I would be using this on a server so I dont need monitors or other stuff. All that would be require would be power regulators for 12V, 5V and 3.3V right? Wouldn't that be more efficient? (the battery would last longer due to less power loss on conversions I think)  And wouldn't it be cheaper?  Thanks, Ralms

Question by RicardoM146   |  last reply


how to reduce 5v dc to 2.5v dc?

I need to reduce a 5v power supply to 2,5 v for a certain application, I've got a converter that can do it, but want to do it using some electronics any ideas?

Question by fjchorn   |  last reply


Amplify 1.5v DC to 5+v DC?

Hi, Anyone know if I can amplify 1.5v DC to 5+v DC (pretty much any value over 5 works) using the LM358 IC (https://www.sparkfun.com/products/9456)? The datasheet (http://www.sparkfun.com/datasheets/Components/General/LM358.pdf) specifies the power supply range as 3V to 32V however the input voltage range is -0.3V to 32V (top of datasheet page 2). I've done some googling but I'm still not sure about the difference between these two.  Any tips or links on wiring this guy up would be awesome, Thanks!

Topic by sciguy77   |  last reply


dc-dc Buck vs boost efficiency

Hi guys. When you  use solar panels and have gadgets with different voltage requirements  that you want to power up. I need atleast  2 different outputs, 5v and 12v  ,   so which is most efficient ,  12/15v panels that you  regulate to 5v , or  5v panels boosted  to 12v? is there any general advantage in either case and i,m talking about using  cheap ebay switch regulators / boost converters,  not anything expensive hi tech. regards

Topic by kristerh   |  last reply


ac too dc

Is there a way to convert dc too ac power?

Topic by minecraftpotato   |  last reply


DC to DC converter

Hi ppl, for electronics A level coursework i am hoping to build a DC to Dc converter to use to power high power leds. As far as i understand it will convert DC to AC, use PWM to alter the current out, and then convert this back to DC giving a constant current out. These are available in devices (known as buckpucks) but for my coursework i hope to build a similar thing on Breadboard. This is really a question for the engineers and if they could give me some advice on anything to do with this it would be great! Thanks ppl

Topic by drummer ian   |  last reply


DC motor regulation

I am planning to build a small gearbox that depends on a steady rpm from a 3V dc motor. I understand that the output rpms will change in correlation to the fluctuation of input power. My question is, if I used a regulator to regulate the input voltage from 5V to 3V, will that keep the motor rpms steady?

Topic by Tman179   |  last reply


DC To AC Converter?

Hello, It Is Now Summer where I live, and it is getting VERY hot. I Want to put in an Air Conditioner, but whenever I do, My electric bill goes through the roof! I have an old car part (Cannot remember what it is called, its the part that uses the turning engine to charge the battery or something like that... I Cant remember) and I would like to use that (made into a mini wind turbine) to charge my spare car battery, and use a DC to AC Power Converter to power the air conditioner... I Have an DC - AC converter, but its not powerful enough... I Need To Build One That Can Power The Air conditioner.... Soon... Its Starting To Get REALLY hot... Thanks...

Question by Tuckoguy   |  last reply


Increasing DC voltage

I need to increase the voltage of a battery from ~30v to ~230v, the only way i can think of doing this is somehow pulsing the DC rapidly to create a sort of "pseudo AC" then using a standard transformer to increase the voltage, followed by the standard rectification process. My problem is how to pulse the DC (bearing in mind the pulse will probably need to be in the order of kHz, and the device being powered at 230v has a power rating of 400W) and how to after the rectification process implement a pwm system. In addition, the method of increasing the voltage strikes me as extremely inefficient, so if anyone has any other ideas I would be very great full. Thank you for any help you can provide.

Topic by csharpdeveloper   |  last reply


DC MOTOR CONTROLLER

RELATED TO DC MOTOR CONTROLLER (EV VEHICLES) 1: Need for large number of capacitors in the power circuit (store the charge and dissipate to which part of the component mosfet or diodes ??) ? 2: what are diodes parallel to the mosfets for ? ( other than preventing the back emf coming from the motor ) and is it have anything to do with firing angle ? 3:advantage of using many mosfets in parallel than using a single mosfet and on what basis must that mosfet chosen? I am from India a college student pursuing my electronics engineering and making motor controller,i am able to get all the circuit details and how the motor controller works but i have above few doubts

Topic by doraditya   |  last reply


DC time delay? Answered

Here's the situation-I close a switch completing a circuit,providing DC power to a load(6 volt,0.1 A).But I do not need the load to start functioning as soon as the switch is closed i.e,only after a delay of say..30 seconds.I googled for "Time delay circuits" but the ones I got were either dealing with AC or the transistor -capacitor(Time Constant) based circuits that makes a load function for a preset time after the circuit switch is opened.I think I could achieve this "pre-delay"  with elements such as transistors,resistors,capacitors etc. but I can't figure out how.Please suggest possible circuits that can be used to achieve my purpose.

Question by Adarsh_tronix   |  last reply


Large DC motor

I'm looking for a relatively cheap motor that would be large enough to spin around a nerf Vulcan. I don't know much about what kinds of motors would be good, or where I could get them. From what I've found, they're not that common and they're super expensive. Does anyone know where I could get one for under 100 dollars? It doesn't need to be fast. Thank you in advance for your help.

Topic by alecnotalex   |  last reply


Converting Dc to Ac

Ok this is my first post on this site so forgive me if i sound stupid...i like to tinker with things so just to tell a little about things i have done...completely rebuilt a pc..wired up an adapter for an old xbox to work on pc...the easier things....fixing frayed speaker wire....rebuilt/and upgraded a zune 30gb to zune 60gb the usual stuff...my most proud is overclocking my amd 64x2 4000+ to 2.9Ghz.....everyone said it couldnt be done...........anyways on to my question.......i want to know what all i will need to convert Dc to Ac power for a set of old desktop speakers i found in my closet.......i have an idea of what i want to be able to do.......put them in a backpack and make it portable.....currently i have two old 7.2v 1200mah Rc car batteries that i would like to use to power it.....and i also have a charger for them...it can charge and discharge...its old but works....so now my next step is what else am i going to need to complete this project...i dont know a whole lot about electricity but know enough to follow directions...if someone has already done this or knows how to and could walk me through what i need to do i would greatly appreciate it....

Topic by Celestial_Artisian   |  last reply


DC supply for inverter

Hello. I need to figure out the component values for a "simple" high current power supply... and whether the component costs would even be feasible. I plan on buying a 3Kw output 12 DC inverter for use in Spain. I have several US devices that I don't want to run off a step-down transformer as running them at 50Hz instead of 60Hz will cause heating and eventual failure (I experimented with my Technics power amp, it got very hot and started to smell, then the output went way down... it's now on the "one of these days I'll open this up and take a look" pile). So, what I need to design is a 220 to 12 volt/300 amp unregulated supply. Ideas, anyone?

Topic by tsmyles   |  last reply


DC Motor Problem?

Hi , to whoever is reading this .I wired 2  3v dc toy motors in series and I used about 4.5v as the power source. As I powered it up one motor spun fast and the other spun slower , so I thought the one running slower was defective an so I bought another motor and wired it in series with the  that was spinning fast and thought their speeds would be equalled, however the new one I bought started running faster and the old I one I had that spun faster began spinning slower than the new one. I tried the new one with the old one that had been spinning slower and arrived at the same result.. Could this be because I wired the motors in series ? I  Really need help s o please help me and thank you in advance and for taking the time the read this.

Question by Strontium   |  last reply


AC to DC Converter

Anyone know how to convert an AC to DC without using the Neutral Cable. Just a Single Live wire. Is there a way to split the incomeing Live wire to positive and negative phase and convert to DC from there? ANyone have any ideas?

Topic by Paradigm812   |  last reply


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   |  last reply


Converting AC to DC

I have a single phase 3.5 hp AC motor, I would like to convert to a 12 volt DC.I'm no electrical expert but I think it can be done.From watching youtube vids and asking Mr. GoogleI understand a DC motor runs slower say 1750 rpm,where my AC motor spins at 3,450 rpm.I also understand a DC motor has brushes.Besides the speed being different, and changing the cord out,is there any reason WHY this couldn't be done?Any potential drawbacks?Any help or knowledgeable advice would be much appreciated.Thanks guys,skip

Question by xhdskip   |  last reply


WANTED: DC motor

I'm trying to build a wind turbine. If anybody has a DC motor from a old treadmill, electric scooter, etc. I would love to have it. The idea motor would be one with highest volts per rpm. That means low rpms and high volts. Let me know if you have something.

Topic by JSTArollin 


sony dcs-w50?

Not only is my lcd screen cracked but my flash doesn't work, saw how to fix screen need instruction to fix flash in my camera,?????  HELP

Question by woody55   |  last reply


PIR DC Motor? Answered

Hi all, I am trying to set up a dc motor controlled by a PIR sensor using an arduino.  When the PIR sensor is triggered, I would like the motor to turn on for half a second and then off.  However, no matter what "delay" I write into the sketch, the motor always stays on for around four seconds.  Could someone please help me? The sketch I have written is below and have provided a picture of my set-up: const int pirPower = 12; const int pirIn = 13; int motorPin1 = 3; void setup(){ pinMode(pirPower, OUTPUT); pinMode(pirIn, INPUT); pinMode(motorPin1, OUTPUT); digitalWrite(motorPin1, LOW); digitalWrite(pirPower, HIGH); } void loop(){   int value= digitalRead(pirIn);     if (value == HIGH){       digitalWrite(motorPin1, HIGH);       delay(2000); //will not start if = 0-20.  The signal is stronger the higher the delay goes.  Time active remains the same.       digitalWrite(motorPin1, LOW);     } }

Question by Josh_Lucas   |  last reply


How to step down 110V DC to 46V DC?

Little about the beast: This is a home build rectifier made of x6 KBPC3506 which comes out to total capable throughput  of 210Amp This THING connects to an outlet via thick power cable. I measured the output when plugged and it is 110V DC. So this got me thinking is there an easy way to step down 110V DC to like 46V or 60V? WHY? Well I have an electric e-bike and just as a fun project I wanted to see if it is possible to replace the battery with portable gasoline generator and then AC 110V from generator turn it to DC and step it down to a little more than 46V. Of course I will have little baggie at the back of the bike :-)

Question by Redion   |  last reply


Circuit Design for DC to DC Buck-Boost Converter

Sir, I am Anand from india, I will made a project based on bicycle. I have take 5 to 80v From my Bicycle pedals. Generator power is in AC 3-Phase. I want to made next step. in this I want to this 3-Phase AC 5 to 80V are constant At 48V DC. I put the 4 batteries in series. 12V 20Ah battery I use. I want to charge this batteries please help me. Thank you.

Topic by AnandC10   |  last reply


high capacity joule thief/dc-dc converter

I'm trying to make a dc-dc converter with the following characteristics: Output = 5V regulated at up to 30mA = 150mW Input 1V (or lower) from a slightly flat AAA. Assuming a pessimistic circuit efficiency of 50%, then the input current would need to be 150mW / 0.5 / 1v =  300mA which I think a AAA is capable of supplying. I'm using a variation of "led torch circuit 2" from http://www.talkingelectronics.com/projects/LEDTorchCircuits/LEDTorchCircuits-P1.html, but I've replaced with the 1n4148 with a schottky diode and replaced the 2 LEDs and 29R resistor with a 5k6 and 1k resistor respectively; this should limit the output of the circuit to just under 5v. I have a 150R resistor to provide a 30mA load to the circuit. When the input is 2.4V, the output is 4.62V which is close enough to 5v for me.  But if I decrease the input voltage to 1.14V, then the output voltage falls to 2.7V which is not enough. I have tried half a dozen hand wound transformers with various turns ratios, wire thicknesses and shapes (slug and toroid) but am unable to achieve 5v out (at 30mA) from 1v in. Does anyone have any suggestions as to what to adjust, or perhaps a better circuit?

Topic by GrotBox   |  last reply


DIY 9V DC to 110V AC inverter, and/or 9V DC to 19V DC transformer?

Hi, I want to build a 9V/110V DC/AC inverter, so I can power up things like my laptop with a car lighter socket. It would be always nice to be able to use electronics in the car when I'm traveling... What kind of components will I need and how would the schematic looks like? If DC/AC is a hard task, how would I go about building a 9V/19V DC/DC transformer so I can at least power up my laptop on the go?

Question by ddolbi1   |  last reply


How to make an BJT astable multivibrator run faster than 30Khz that works?

I am working on a dc to dc converter and it works but it seems to me that when i go higher than that it doesn't work anymore. I am using two C945 transistors. The resistor values for R1 and R4 are 1K and for R2 and R3 are 15k . For the capacitors C1 is 2.2nf and 1nf for C1. i have tried putting in smaler capacitors and increasing the two base resistor values. BTW its for a dc to dc converter that im working on. I also have no idea how much inductance on the inductor is. I am try to step up 6V dc to 15 V. It works put its low on power thats what i want.

Question by josh1001   |  last reply


convert 5v DC to 3.3v DC?

Hello would somebody help me with this please, I am not much of a "electronic" kind of guy so this is a big problem for me. I lost the power adapter of our office router WRT54GC (linksys) and my boss has his finger cross on me. I only knew of its power which is 3.3volts 2A DC. From my location, it is very unlikely to obtain a replacement or an equivalent adapter. I have salvaged a power supply of and old printer that gives off 5.0V 2A DC but the router would not run with this voltage. I will really appreaciate it if somebody would be able to help with a step by step explaination on how to lower the 5v to 3.3V . Thank you very much.

Topic by gincasty   |  last reply


how can i drop 1A dc to 500ma dc? Answered

I have an AC-DC power supply with voltages of DC 3 - 4.5 - 6 - 7.5 - 9 - 12V and 1000ma and i want to drop this down to 500ma!

Question by thecookiemonster   |  last reply


Connect a DC plug to a Timer?

I have 2 strands of led lights that go up a Flagpole on my rv, I am trying to figure out how to connect a timer through the DC Plug Thanks in advance Mike

Question by quine9   |  last reply


DC Motor- dead or alive?

I've got a DC motor from a treadmill that when I spin it generates a small voltage then drops off to zero even as the motor continues to spin. Is it shot? Can it be repaired, if so, at what cost.?

Question by haroun   |  last reply


DC power electric controls

I have a great idea and looking for a type of DC electric control that can handle a charging system and power release . IS THIS POSSIBLE !! and can there be a program written that can control the amount of dc power released? of course i want to control multiple incoming power sources and release the energy it creates.   ANY AND ALL IDEAS WELCOMED!

Topic by ramonc123   |  last reply


How to convert dc to ac? Answered

Hi! Can anybody tell me how to convert dc to ac i actually want to convert 9volts dc to 9 - 7 volts ac cause i need to supply this ac voltage to a step-up transformer so that it will convert it into 200volts the real problem is when i provide 9volts dc to the step-up transformer it only gives out 41volts in output but when i gave it 9volts ac from another transformer it gives out 200volts ac and that's what i need but i need it to be battery powered so i need to convert the 9volts dc supply from the battery to 9 or less volts ac that's all i want to ask how to do it!

Question by ubdussamad   |  last reply


Square wave DC transformer Answered

If I was to feed a dc square wave into a transformer would I get a dc square wave as an output?

Question by workinprogress37   |  last reply


Potentiometre for 3v DC Motors? Answered

Hey Guys, Today I Need help selecting a potentionmeter for my 3v dc batteries, The setup will be like this, There will be 4 3v dc motors in parelllel drawing about 800 mah i think with a 6v 2 amp 4 aa cell battery pack. I want it to be so that when i turn the potentiometer to the lowest the motor goes to the slowest speed (or close) and when i do it the other way it goes to the highest speed (at 6v). Thanks in advance. -Prickly Potato

Question by SA-DIY   |  last reply


Universal DC to DC adapter?

Does anyone know where to purchase a universal DC to DC adapter? I'm trying to run a webcam off of a specific amount of electricity from a battery pack. 

Topic by DarrenG   |  last reply


DC Motor Control Help?

A very long story short, I desperately need assistance in knowledge with some motor control. I need to control 2,DC 6v motors with encoders that include 6-pin 2.0mm pitch PH JST cables that break out motor inputs. The bottom line would be what do I need to control these motors, to go forward and reverse, and operate it from a wireless controller? I appreciate any and all help! Also, this is our motor: http://www.trossenrobotics.com/p/Robot-DC-Gearhead-Motor-6v180rpm.aspx

Question by NickWeav   |  last reply


DC motors & stepper motors

I have 13 stepper motors and 10 dc motors for sell. I just have way too many laying around. I would like to sell them all for 40 dollars shipped using paypal. I'm hopping to sell them to help fund my CNC project. I also might be adding more motor as I find them.

Topic by r1dd1ck913   |  last reply


Electric Power DC Generator

I've been toying with the idea of trying to build an electric generator that after receiving initial power to start, could power an electric motor that would in turn somehow power 1 or more generators and would not only produce enough power to continuously power the motor, but also allow it to distribute power for use with an inverter or stored in batteries. Am I crazy that I dont see where anyone has tried this or is it just not possible? Obviously, there would be friction forces from the generator(s) on the motor and it may be difficult to produce enough power to even run the motor, but does anyone know of anyone that has tried this? I've been reading peoples posts and really enjoy looking at other peoples ideas on this site and decided to sign up. Thanks.

Question by AggieTX   |  last reply


DC motors as generators in parallel?

Hey guys, im doin a project, ill be using two cordless drill motors with a maximum output of 12v each and unknown amp atm. My question is this: Both the outputs of those two motors will equal 24 volts, but I want 12 volts and increased amperage - this will, for the most part, be used to charge a 12 volt lead acid battery and I dont require the safety police on this one. So, can I take both outputs of the dc motors and wire them in parallel and have a resultant potental 12v maximum? Or will I have to use electrickery?? I have only a novice/intermediate skill in electronics and my parts come from re-using old scrap technology. tx, Sky

Topic by Sky Graham   |  last reply


Lego apocalyptic DC project

Alright, I'll admit it. I went to brickfair. There, they had an apocalyptic DC there, and I got inspired. However, I think I need quite a few more pieces. I'll post this in a question, too: Anybody know where I could get a ton of legos for a good price? I earn 10 a week, so try to make it fit that. Thx, builder968

Topic by builder968   |  last reply