Disposable Camera Nixie Tube Driver

56,372

107

73

Published

Introduction: Disposable Camera Nixie Tube Driver

Before I get too far in this instructable, I would like to say that this was not my original idea. You can see two implementations of this idea already on Flickr. The links are:
http://www.flickr.com/photos/mdweezer/322631504/in/set-72157594420700670/
http://www.flickr.com/photos/samwibatt/1610784412/

On with the instructable! This documents how to turn a regular disposable camera into a high voltage power supply capable of driving 2 or 3 medium-sized nixie tubes, for roughly $8.

***Disclaimers***
This instructable works with voltages in excess of 250V. This is more than enough to give you a potentially fatal electric shock if handled incorrectly. If you are unfamiliar with how to work with high voltage, please refrain from performing this instructable. Exercise caution throughout the following steps to avoid electrical dangers. If you choose to undertake this instructable, you do so at your own risk.

This instructable involves soldering. A soldering iron becomes very hot during its use, to the point where it can cause instant second-degree burns. Exercise caution throughout the following steps to avoid burns. If you choose to undertake this instructable, you do so at your own risk.

Step 1: Gather Materials and Tools

For this instructable, you will need:

A disposable camera
A potentiometer of 100Kohms or higher
A resistor of 50Kohms or higher
Wire cutters
A small screwdriver (may not be needed, depends on your camera)
A multimeter
A soldering iron
Solder
Red wire
Black wire

Step 2: Disassemble Camera

This step is going to vary depending on the camera you choose to take apart. I will post a pictorial description of how I took mine apart, but know that not all cameras are alike.

Also, this step is probably one of the more dangerous steps, because you do not know if the capacitor is charged currently. Do not touch the capacitor or the flash circuit at this point, it may still have energy stored that could electrocute you. Being electrocuted is a bad thing.

Once you expose the capacitor, I highly recommend discharging it. This can be done by touching both wires coming out of the bottom of the capacitor with a screwdriver or other metal object. Make sure the object you use to discharge with has an insulated handle, and only use one hand to minimize risk of electricity flowing across your chest. I also recommend wearing safety goggles, because if the capacitor is charged, sparks will fly, and you don't want one of those sparks in your eye. (sparks can also known as superheated airborne metal fragments)

Step 3: Attach Wires.

To make this circuit more convenient to use, it is time to add some wires. Notice the capacitor has a stripe on it. The black wire will connect to the lead beneath the stripe, and the red wire will connect to the other lead.

Step 4: (optional) Make It Safer

This step is optional, but I highly recommend it.

Solder a resistor across the leads of the capacitor. This will enable it to self-discharge in a controlled manner. You can use any resistance over 50Kohms, but the lower the resistance, the faster the circuit will decrease to a safe voltage. I clocked mine, at 100Kohms, the circuit went from full power (about 230V) to a more reasonable 20V in about a minute. 50Kohms makes the circuit safe in about 30 seconds.


Alternatively, you can completely remove the capacitor and never need to worry about stored charge again.

Step 5: Case It Back Up.

In the interest of maximizing safety, I chose to put the circuit back into the camera's shell. I ran the wires out of the rear viewfinder window, so I had to poke a little piece of plastic out of the window.

Step 6: Create the Circuit and Use.

Now, wire up the circuit for the nixie tube. Put the potentiometer in between one of the leads and the nixie tube, and adjust as needed. With my IN-12A tubes, 200Kohms pass about .3 mA, which is enough to illuminate the tubes, but is not very bright. Experiment with your own tubes (use the multimeter here). Sorry for not showing pictures of the calibration process, but this circuit blew out my multimeter when I accidentally created a short circuit. Like I said, be careful.

When the camera is on, the high voltage is present, so please exercise caution when using this.

Share

    Recommendations

    • Make it Move Contest

      Make it Move Contest
    • Clocks Contest

      Clocks Contest
    • Oil Contest

      Oil Contest
    user

    We have a be nice policy.
    Please be positive and constructive.

    Tips

    Questions

    73 Comments

    The capacitor just blown up in my face :S

    What would be the easiest way to step this (mine outputs ~260V) down to 200V? I am looking to drive 3 IN-1 (ИН-1) tubes.

    2 replies

    Easiest: increase the series resistance. I don't know the properties of your tubes in particular, but if you model them as a 200V ideal voltage sink, then use Ohm's law to find the resistance needed to get your tubes rated current at 60VDC.

    Is it elegant? No. Not at all. Will it work, sure!

    Thanks, that was helpful, but it turns out the power supply is so piss-weak it steps down to below 200V as soon as you hook anything up to it. No adjustment required!

    P.S. You could also just use a trimpot as a quick-and-dirty voltage divider, if needed.

    ive accedentialy shorted one of those caps with my finger.

    i guess as long as its on the same hand, theres no worry (not across the heart) but it HURTS LIKE HELL

    12 replies

    I was burned by a transformer from a scanner fluorescent lightbulb. Luckily it was just across my finger. Hooked up to a computer power supply, ouch... I had charred spots on my finger.

    I only got shocked by a small transformer, nothing big, it was the transformer that comes with the "Radioshack Learning Lab" kit.

    Hey! I have that kit. It's pretty useful. I'm still learning from it. I also made a shocking circuit from it and you could adjust how much the shock hurt. I don't think that kit is still being sold, is it?

    Its true, if you only work with one hand, and zap yourself only through that one hand, you are less likely to stop your heart via electrocution.

    That being said, enough of a zap can create internal burning, putting the victim into shock, so there is always the chance of a fatal shock when working with voltages above 36V (some sources say as low as 12V).

    Always remember, electricity is our friend, and just like any friend, you better treat it with respect, or else you will get burned.

    I got a shock of a car battery once, despite my beliefs that there isn't enough potential difference to across our body

    All depends on the person, some can feel shocks from sources as low as 10V, some don't notice till much higher.

    I got shocked by an EL wire inverter and it wasnt pretty. It's output was 200 volts ac but it only ran off 2 AA cells. So, i guess it is a matter of current, not volts. My slayer exciter outputs 4000 volts and it burns my finger!

    Current and voltage play parts in how dangerous it is, but current is the main factor.

    Yes. If you don't have enough voltage, you cant pull the current needed, however high voltage doesn't meen that it will pull a large current. the power supply high not provide enough of a puch.

    U=R*I

    so if R is high and U is low, I needs to be low or the math wouldn't add up

    Pretty much any wall wart can kill you, hence why GFIs trip at about 4 milliamps (but wont work unless current isnt returning, like using two hands to stick two bare wires into the hot & neutral of a GFI, it wont ever trip if Iin=Iout).

    Higher voltage makes the current able to travel along or penetrate your skin.

    While that's true voltage is not what kills you. Tazers operate at 1mill+ volts! It's the amperage that is dangerous.

    A few people have been killed in my old line of work, 48v DC systems in telecom offices.

    I only got ring voltages on my forearm when reaching in to hook up wirewrap connections on the AT&T switch.

    You dont always know that cap energy wont go in your finger, up a nerve of vessel and navigate its way to a vital organ and not right out again.

    you could DIE

    Um... its not the voltage that kills its the amps... and realistikly think about it. Can u touch both ends of the 1.5V battery with out dying? V=ir therefore if you increase the voltage u decrease the current thus making it not deadly. HOWEVER THIS DOES NOT APPLY IF U HAVE A PACEMAKER!! That zap can stop it... basicly: Yes use caution when working with electricity No u wont die if you touch the cap. It will hurt a LOT tho. BTW a car battery can kill even if it only has 12V because it can out put MASSIVE amout of current!

    1 reply

    What you said does not make sense. "V=ir therefore if you increase the voltage u decrease the current thus making it not deadly." Basic algebra states that increasing V while holding R constant will result in an increasing I.

    You are correct, that it is current that kills, not voltage. However, the human body has a skin resistance of approximately 47kOhms, when dry, so you need a reasonably high voltage to generate a dangerous amount of current across the chest. Basic V=IR shows you only need about 1V of potential difference to generate the generally regarded to be "lethal" current of 10uA across the chest, but don't forget the cross-section of the chest is rather large in comparison to the heart, so not all of the current flows through the heart.

    Once you exceed about 36V though, that cross section difference is not always enough to prevent a lethal current from flowing through the heart. Some people are more sensitive to it than others (some people can feel a jolt with as little as 10V), sure, but you won't see me grabbing two terminals at a 36V potential difference with opposite arms. Because these capacitors can let out a jolt at upwards of 300V, you see how they can be dangerous; only one pulse of "enough" current is needed to do very weird things to the heart.

    This is why when working with high voltage, you want to use only one hand, and pocket the other. This way, current is not inclined to flow through the chest; it will stay in the arm, maybe cause external and/or internal burns, but that's a far better fate than stopping the heart.

    It is actually known that a 9V battery can kill; if you manage to pierce the skin with both terminals in such a way that the current chooses to flow through your bloodstream into one arm, across the chest, and out the other, enough current is generated to stop the heart. This is because blood is rather low-resistance, so a high current is generated. Without your skin acting as a safety resistor, even surprisingly low voltages can be very dangerous.