Introduction: Capacitor Charger

Picture of Capacitor Charger

This project details the process of building a device capable of charging a flash capacitor (the type of capacitor found in disposable cameras).

What possible use could anyone have for a capacitor charger?

You'd be surprised /lie

Action packed video after the jump.




Is it not fascinating?

Step 1: Materials

Picture of Materials

The materials will end up running you somewhere between 0 and 20 dollars.

1. Disposable camera w/ flash
2. Soldering iron and solder
3. A few square inches of 1/4" thick wood, acrylic, glass, etc.
4. Super glue / hot glue
5. Momentary push button switch
6. Syringe tips (Come with ink cartridge refill kits)
7. Wire
8. AA battery holder

Step 2: Disassembling the Camera

Picture of Disassembling the Camera

Before removing the case on the camera, take a photo using the flash to make sure the capacitor is fully discharged. If there is no film left in the camera (thus making taking a photo impossible), then charge the flash, and slam the bottom of the camera down on a hard flat surface. The force should be enough to trip the shutter, which should set off the flash.

The next step is to take apart the camera. We must pretend to be the cameras friend so she doesn't get scared and call the police before you get a chance to harvest her organs. The conversation should go something like this:

(1st picture)

Me: Why, Mrs. Kodak you sure do look warm in all those clothes.

Mrs. Kodak: Well it is kind of hot in here.

Me: No reason to be uncomfortable. Let me help you take them off.

Mrs. Kodak (shyly): I don't know, my husband is going to be home soon.

Me: What, that 24 shot roll of film? I bet he has never even properly pleasured you ... let me guess, he just sits inside of you as you expose yourself to him.

Mrs. Kodak (offended): Hey!

Me (seductively assertive): Its ok baby, let Billy show you how a camera should be held.

(2nd picture)

Me: There don't you feel better without all those uncomfortable clothes.

Mrs. Kodak: (blushes)

Me: (pulls out screwdriver and smiles menacingly)

Mrs. Kodak: Whats that flat head for?

Me: It puts the lotion on the skin, or else it gets the hose again.

Mrs. Kodak: Huh? ...... Ahhhhhhh! hrmfffff .... gurgle gurgle

(3rd picture)

Me: *Rips Mrs. Kodaks guts out*

Harvest the circuit board from the camera's insides, and dispose of the rest of the body in the woods.

Step 3: Modifying the Circuit and Assembling Board

Picture of Modifying the Circuit and Assembling Board

To check to make sure the capacitor is fully discharged: Take an old screwdriver and bridge the gap between the capacitor's two leads.

Unsolder the capacitor and battery clips from the circuit board (make sure to keep note of their polarity).

Tip: Using two different colors of wire will help you remember polarity

There should now be four empty connections in the circuit board, two for the battery and two for the capacitor. Solder a foot long section of wire into each of these empty holes.

Finally, set the flash charge button/switch so that it is normally closed instead of normally open (picture 4).

The pushbutton switch, battery holder, and syringe tips will all go on the top of the board, while the circuitry and wire connections will go underneath.

Before drilling the acrylic (plastic, wood, w/e) piece, lay out the different components on the the top and bottom of the board to make sure everything will fit. Once you have found an orientation where all the pieces fit, drill holes in through the board, and attach the components.

Use hot glue to seal the syringe tips and battery connector (the pushbutton has a screw on nut) in place.

Step 4: Making the Connections and Adding Legs

Picture of Making the Connections and Adding Legs

The pictures will be of more help then my written description

Wire connections:

(the circuit board battery wires)

1. Solder the positive circuit board battery wires to one lead on the pushbutton switch, and solder lead on the pushbutton switch to the positive terminal on the battery holder.

2. Solder the negative circuit board battery wire directly to the negative terminal on the battery holder.

(Capacitor wiring)

1. Wire the negative circuit board capacitor wire to one of the syringe tips, and the positive circuit board capacitor wire to the other.


1. Glue on some legs. I used a combination of super glue and hot glue.


1. Most disposable camera circuits have LEDs to indicate when the flash is fully charged. Bend (or rewire) the LED so it is visible to you when you are charging the capacitor. It will be useful in letting you know when the capacitor is fully charged.

Step 5: Using

Picture of Using

(After checking to make sure it is discharged!) Straighten out leads on the capacitor that was previously unsoldered from the circuit board. Trim the leads down to about 1.5 cm and bend them so then will easily fit in the syringe tips.

Insert a battery into the charger, and you are ready to go.


1. Insert a fully discharged 330v flash capacitor into the syringe tips. Make sure the capacitor has proper polar alignment with the charger.

2. Push and hold the button until the LED illuminates.

3. Remove the capacitor.

Uses for a charged capacitor:

- You shall see


Secretly_an_Engineer (author)2016-05-01

This got weird for a moment...

Hotel Lima (author)2014-09-10

Do you think it would be possible to arrange two charging circuits from two disposable cameras in either parallel or Series to increase the speed of the charge. Im planning to use capacitor banks so i need a faster charge. Or if you know another way to "safely" charge a cap bank faster.

scamp (author)2008-06-02

who likes this one? its a 25 volt i think and 1000 mF would that hurt badly/kill some one?

Sandisk1duo (author)scamp2008-09-05

25v is not enough voltage to go thru skin (sorry) 50+ volts and you start to feel it, but if you lick you finger and touch the terminals of the 25v capacitor, you just might be able to feel it You need a 300V+ and a couple(20+) hundred uF to leave a mark

ggiihh1 (author)Sandisk1duo2008-12-29

if 25v can't go through skin how come if you can test a 9v battery w/ your tongue?

rdavis2 (author)ggiihh12013-12-31

please please put a 300v capacitor on you'r tongue and tell us how that goes for you

Sandisk1duo (author)ggiihh12008-12-29

cuz your tongue is wet, and has WAYY more nerves then your skin, so you can't really tell how food tastes with just your finger (duh)

ggiihh1 (author)Sandisk1duo2008-12-29

maybe i CAN taste with my fingers!

Sandisk1duo (author)ggiihh12008-12-29

well you are the only one that can do that....

Gamernotnerd (author)Sandisk1duo2009-01-31

Not so cool if you are a garbage man.

MrPyro1010 (author)Gamernotnerd2009-07-24

or taking a dump ..... hahaha

josh1324 (author)MrPyro10102010-09-10


ggiihh1 (author)Gamernotnerd2009-02-01

Luckily i'm not.

davidprosser (author)ggiihh12009-01-02

how cool would that be though...... ??? hmmmm .

Madrias357 (author)Sandisk1duo2009-08-08

Note to all people here: this is not a good suggestion for finding out whether or not the capacitor's charged...

Sandisk1duo (author)Madrias3572009-08-09

yeah, that's true

mettaurlover (author)Sandisk1duo2009-01-07

hm... what would a 250 volt 4500 capacitor touched you?

Sandisk1duo (author)mettaurlover2009-01-07

depends on if it is charged or not... charged, i wouldn't like it one bit... discharged, sure!

Sandisk1duo (author)Sandisk1duo2009-01-07

although i do have a 330v 4000+ uf capacitor

mettaurlover (author)Sandisk1duo2009-01-09

wow... i now have a 50 volt 4500 uf capacitor with solder on the ends of the leads... it contact solders anything it discharges through...!

Wesley666 (author)mettaurlover2009-02-20

I have a capacitor rated at 500v at 10000uF, how much would that hurt?

Emett_builds (author)Wesley6662012-02-09

Probably kill you withh a full charge.

Wesley666 (author)Emett_builds2012-02-11

Depends if it can deliver any sort of current. If it can discharge 500v doesn't mean it will have anywhere near the amperage to kill you.

mettaurlover (author)Wesley6662012-02-11

Well, depending on how large the capacitor itself is, it could kill you. If it's large enough, it could actually have the amperage to kill you, but if it's as small as it could get while still having that capacity, probably not.

master key (author)Wesley6662009-06-17

I have a capacitor thats 16v at 68000uF and another a 50v 6800uF

mettaurlover (author)Wesley6662009-02-22

a lot. i'd not put that anywhere near my skin if i was you...

Wesley666 (author)mettaurlover2009-02-22

OK, what about a cap rated at 1500v at 120uF?

ReCreate (author)Wesley6662009-04-02

It will probably be discharged before you get a chance of removing it from the charger

mettaurlover (author)Wesley6662009-02-23

pain. that's the only word i can think of as a result of touching that.

Wesley666 (author)mettaurlover2009-02-23


evanwehrer (author)Sandisk1duo2010-05-02

 I have a 16V 77000MFD capacitor....two actually. Their BIG

mettaurlover (author)evanwehrer2010-05-02

I have a 200/680/5442 if anyone knows what the third number means...

silencekilla (author)Sandisk1duo2010-10-02

wrong it only takes 1 volt to kill you and if it goes across your heart you are 70% more likely to die from it

zeosrule (author)silencekilla2011-05-03

Not to be rude but it is one amp not one volt

baecker03 (author)2013-10-19

you can go to any photo processing store (walgreens) and ask for the disposable cameras they will recycle... after getting some weird looks and having your girlfriend pretend she doesn't know you, you will more than likely get as many as you can carry. save you 12 bucks and you don't have to feel guilty about wasting the film. oh, and the batteries which are contained within are nearly new. would strongly advise shorting out the leads of the cap after removing the battery as well. be careful while doing this, as there is a fairly loud snap / large spark when this happens. could also use some type of dummy load as well to avoid the snap i guess.

BOOM OWWWW (author)2013-08-30


whiskeysausage (author)2013-06-16

can you 'trickle' charge a capacitor?

I understand that a capacitor must be charge by the same voltage that the capacitor can hold before the plates reject incoming. I.e. - a 9v battery can charge a capacitor to 9volts. No more no less.

There is though, no mention of amperage. Can you trickle charge a capacitor at 9volts, but 0.001amps, and over time, achieve a fully charged capacitor capable of discharging 9v worth of energy at 1 amp?

Or is there a pre-determined 'amp' rating that capacitors must be charged at?


agm88 (author)2012-11-16

epicly fuunnyy and weird at the same time =)

wolf996 (author)2012-03-02

Ewww!!! Silence Of The Lambs Reference!!!

what of you overcharge the capacitor? what happens?

With the circuit and capacitor described in the 'ible, you can't "overcharge" it. It actually never reaches a complete charge. It just keeps getting closer and closer.

If you were to use a cap that wasn't rated for the voltage that the circuit supplied, the cap would fail. I think the cap would internally short itself out, then kill the charging circuit. I don't think t would explode or anything, but you never know... My bet is that it would just stop working.

bibbibbib (author)Dodge2010-12-13

so its like an asymptote?

Dodge (author)bibbibbib2010-12-14

Exactly. When you graph the charge pattern you get an asymptotic curve.

guitarmonk15 (author)2010-06-24

where did you get the syringe tips? Is there anything you could use as a substitute, like an ic socket?

Dwarg (author)2007-12-31

gotta add this in, (clears throat) BWAHAHAHAHAHAHAHAHA!!!!!!111one!!!

sethman (author)Dwarg2009-04-01

what does it do

MediocreNinja (author)sethman2010-05-16

 It does what it says it does, charge a capacitor

tim13211 (author)2010-02-02

would this work if you change the cap with a car battery? B/C i was thinking the input would be from my waterwheel and output would be to the car battery.

Would this work, if not how would I mod the circuit?

webbofthedesert (author)2010-01-14

ha lol, that got wierd somewhere around the first picture, yet it was highly informative, i look forward to putting that convosation into action... and maybe making a capasitor charger.

p.s. first big LOL i've had all week, thanks.

octavian234 (author)2009-11-25

So could i use this to charge a leyden jar?

About This Instructable




Bio: Working wireless-ly.
More by Tetranitrate:Laser Glow BoardE-BolaLaser Tattoo
Add instructable to: