555 Voltage Doubler

Batteries are a great way to add portable power to your project/device but often you require higher voltages than a single (or multiple) batteries can provide, this usually means connecting many batteries together to get the required voltage (which could add unwanted weight).

This Instructable uses a common 555 timer IC (available pretty much everywhere) to double the voltage of the input DC source while only using minimal external components. This circuit is only practical for low current devises where the input voltage (for the voltage doubler) is between 4-20Vs.

(Shown in Picture ^^^^ ~6V from 4X1.5V batteries being increased to ~13V)

Step 1: Materials and Diagram

The circuit is pretty straight forward to build. You can either build it on a breadboard for a temporary power supply or solder it onto a PCB and use it with batteries for a compact, light weight and portable power source.

Components

• C1 100nF ceramic capacitor
• C2 1nF ceramic capacitor
• C3/4 4.7uF electrolytic capacitors
• D1/2 1N4004 diodes
• R1 39Kohm resistor
• 555 timer IC

You will also need some hook up wire for the links
Follow the schematic above for wiring details or follow on for breadboard instructions

Step 2: Building the Circuit (on a Breadboard)

*Refer to image for Vin,Vout and GND*

*Refer to image for breadboard pin connections -solid line indicates connection between breadboard holes*

Step 3: ​The Ground

Start by connecting the two GND rails on either side together, this is where everything connected to GND will go to.

Step 4: ​The 555 Timer

Simply place The IC in the middle of the breadboard with the little notch (or dot) at the top of the IC (point it up)

*refer to diagram for pin location*

Step 5: The Components

It's time to add the components!

We'll add them in steps



1. Connect one pin of C1 (100nf Capacitor) to the right GND and the other to pin 5
2. Connect one pin of C2 (1nf Capacitor) to the left GND and the other to pin 2
3. Connect the Resistor (R1-39kohm) from pin 2-3
4. Connect the pin of D1 without the silver (might be white) band to Vin and the other pin (with the band) to a free spot on the breadboard
5. Connect the negative pin of C4 to pin 3 and the positive pin to a blank spot on the breadboard below the IC
6. Connect the non-banded pin of D2 to the positive pin of C4 and the banded pin to a blank spot on the breadboard
7. Connect the negative pin of C3 to the right GND and the positive pin to the banded pin of D2


*your board should look something like the picture above*

Step 6: The Links

Now we must add the links (Using hookup wire)

We will also do this in steps



1. Add a link between the banded pin of D1 (that's the one connected to Vin) and the non-banded pin of D2 (this will also connect D1 to the positive pin of C4) -note this is the yellow link
2. Add a link from IC pin 4 to pin 8
3. Add a link from IC pin 8 to the Vin rail
4. Add a link from IC pin 2 to pin 6
5. Add a link from IC pin 1 to left GND
6. Add a link from the banded pin of D2 (or the positive pin of C3) to Vout


And we're done!

Step 7: Final Testing

Connect a 4-20V power source (batteries work well) to Vin (positive terminal to Vin negative to GND)

Use a multimeter to measure the voltage at Vout (Vout is the positive output terminal and GND will be the negative)

If the Circuit is not working make sure check all connections and components

-Note this will only double for input voltages above about 4V (you will get some increase for lower voltages but not double)

Comments

[RyanC266]

Hello! What would be the max. current this can safely supply?

[MrSirLRD]

it will only supply about 100mA

[daphnem1]

will this design work for an input voltage of 0.3v ?? thank youu

[MrSirLRD]

No it won't, it needs at least 4v

[Deepflower]

Hi I have a project.My problem is voltage doubler circuit.I will make it in a breadboard.But I dont know this diagram is a true diagram for my project.Can you help me ?

[MrSirLRD]

Yeah sure, what do you need to know?

[tab328]

would there be any difference if i used 1n4002 diodes? the first diodes i found were those, i probably have the 4004's so no biggy if they dont work

[MrSirLRD]

I think they will work fine

[tab328]

It all worked ok, but it doesn't double negative voltages. I was using this to amplify output to a motor that would be going forward and reverse; It worked great for forward but I got nothing for reverse, I suppose I will be stuck with a slower motor. Aww well, but hey I can use this for a bunch of other things!

[MrSirLRD]

That's a strange set up, you would use a boost power supply to go into some sort of motor controller or simple H-bridge instead of trying to increase the voltage after the control.

[tab328]

thanks a million for the info guys; I ended up finding some brushed esc's with reverse which is what i was trying to make with a servo and the amp. I dont have the proper fets on hand so by the time i got those here, it would probably be too late. the esc's (hopefully) arrive tommorow but thats irrelevant to you guys i guess

[Prpsjeans]

There is a negative votage doubler you can make with pwm and diode steering. With a couple of fets i think you could do that with your motor and have forward and reverse. I cant remember the name of it, but it is an offshoot of the original diode and capacitor doubler used in many crt sets. Had a russian name like kokrov or someghing like that... hope that helps.

[fmarquis]

Just a comment on my previous comment... I was able to significantly increase the current output by changing the two 4.7uF electrolytic capacitors to two 22uF ones. It can now power a computer fan, but the voltage drop is again too important to be useful for this application.

[Imetomi]

Hi, thanks for sharing, what is the maximum current of this circuit at the input and at the output?

[EricC2D2]

hello all, first circuit i've built to date with a 555 timer ic, don't have a picture yet because i placed a diode in the wrong place and fried half my breadboard....anyhoo, my question is did anyone else have to change the 39Kohm resistor? At first my circuit was not working correctly. my circuit uses batteries of various sizes, ranging from AAAx4 700mAh , AA x16 - 2000mAh), 9V - X 2 - 200mAh , all NiMH rechargeables . Plus 1 12v 12AH SLA. needless to say, i checked and rechecked all connections. I was stumped, so i took wednesday and made sure all the batteries were charged. thursday morning took the circuit completely apart and reassembled it (again with 39Kohm resistor). Vout was only 1v less than Vin . ie.12v IN > 11v OUT. So i started looking for another diagramme, and out of the many i looked through they were all basically the same in design except for R1 which was 33Kohm. long story short, i changed the resistor and the circuit worked like a champ. Then i got smart and placed a diode in the wrong place, the rest is up in smoke.. HAHAHA my multimeter showed 18v@ 0.20A on the 10A setting, while using the circuit to power my 80mm 3-wire pc case fan at the Vin pin of the 555ic chip. i had 14v @ 0.14A from Vout to the pc fan. thanks for reading, will post more info and pictures soon.

[EricC2D2]

Ok, after spending the morning trouble shooting my circuit, i discovered that R1 @39Kohm is not a problem.... so my first working build was with a regular 555 timer ic, well that one got toasted, so i grabbed another one out of my box put the circuit together and it was a fail.. now my circuit is correct, so i swapped the 555 timer ic for another one thinking i had a bad 555 IC. last 555 IC also, only had 2 in my box, and again fail. circuit did not work properly. so i had one more option and that was to use a 556 timer IC instead and it works like a champ... out of the 3 555 timer IC's i had only one was a normal one,a 555NE, the other 2 are 555CS timers and simply would not work.

[jmalunes]

hello. is this gonna work if I'll use 12v source or above 12v?

[MrSirLRD]

Yeap!, I wouldn't use an input of above 25V though

[JamesH12]

I was able to build this on a prototyping board. I added a switch for convenience. The video is here... http://youtu.be/Gm72yHZItmk?list=UUMHBaxQIUeA5RS5w6U2XPfQ Thank you! For the Instructions, and your hard work. Much appreciated.

[MrSirLRD]

You're welcome and i'm glad it worked for you!