Intro: High Voltage Power Supply
While working with electronics, chances are sooner or later, you'll want or need a high voltage power supply.
This is a version you can make at home in a short amount of time.
Of course you should be careful while working with high voltage and electricity in general.
If you indeed hurt yourself in anyway, do not blame me, it is just natural selection at work.
In the second step I will supply a list of the things you need and where to get them.
Also if you find this instructable interesting, perhaps you'll like some of my others:
Step 1: Things You Need
For the power supply you will need:
- Flyback transformer
You can get one from an old CRT television or computer monitor. When you open one, the flyback should have a thick red wire attached to it. Stick a screwdriver into the ground, connect it to another screwdriver with some wire so it is connected to ground and CAREFULLY touch the end of the red wire of the flyback with it.
YOU NEED TO DO THIS, BECAUSE THE CIRCUIT COULD STILL CONTAIN SOME CHARGE AND TOUCHING THE RED WIRE COULD SERIOUSLY SHOCK OR KILL YOU
If you did this, you have discharged the circuit and it is now safe to desolder.
Snip off the red cable, where it connect to the suction cup. The longer the cable, the better.
Now you need to desolder the bottom part of the flyback transformer to take it off of the circuit board.
You can buy a new one or even try using some old ones that don't work anymore (they MIGHT work).
Look for one that's rated for lots of W. Even weak ones should work, but the higher wattage it has, the stronger your supply will be.
This is basically all you need, apart from some wires, hot glue and heat shrink if you want to make it safer.
Step 2: The Mysterious Pins of the Flyback???
In this step we will need to find 4 pins on the flyback transformer. Remember the red wire connected to the flyback? That's one of the pins. Only 3 to go!
Finding the other ones is a little more complicated. DON'T WORRY, it's not THAT complicated.
First draw out the pins on some paper so you can mark the correct ones. You might think you won't get confused later, but trust me, soldering a wire to the wrong pin and wondering why the finished product isn't working is not a happy experience.
For the next part you can use a battery (or multiple connected in series) or a 12V adapter. Now that you've got your pin layout drawn, you should connect the - of your 12V source to your multimeter. Connect the other multimeter probe to the red flyback wire. Connect the + of the 12V source to an alligator clip.
With this setup you can search for the pin that's connected to the red flyback transformer. Simply set your multimeter to the 20V range, touch every pin with the alligator clip and measure the voltages. All will be around 0V, except for one, which will be around half a volt.
That is the pin you've been looking for!
Now for the other two pins that we need.
Set your multimeter to resistance (200ohm scale). Touch the probes of the multimeter together and note the resistance. Later, when you measure the resistance between the pins, you should subtract the resistance of the probes.
Touch the first pin with the black probe of the multimeter and the second pin with the red one. Note the resistance. Now leave your black probe on the first pin and keep connecting the red probe to all of the other pins, again nothing the resistance.
When you cycle through all of the pins, move the black probe to the second pin and cycle through all the other pins again. Continue doing this for all of the pin connections.
The two pins you are looking for, should have a resistance of around 1ohm. (maybe 0.9, the others will be around 0.3ohm or waaay higher than 200ohm)
FOR THOSE OF YOU WHO DO NOT WANT TO READ ALL OF THAT:
-you need the red wire
-connect 12V to the red wire in series with a multimeter and measure the outputs of each pin. The one with the highest voltage is the one you want
-you also need to find the pair of pins that have a resistance rating of around 1ohm.
Step 3: CFL:
The flyback pins were the hard part. Now you only need to get a working CFL and (gently) pry it open with a screwdriver or use a cutting tool to cut the edges off. What we want is the circuit in the CFL, so be careful not to damage it!
Also, the gas in the glass tubes of the CFL is not exactly healthy, so be sure to not break them. Although if you do, don't worry too much, noone dies from a lightbulb.
Clip off the wires that connect the circuit to the socket of the lightbulb. Those wires obviously need to be connected to 230V, as your lightbulb would be.
You will also notice that there are 4 pins on the CFL circuit. They used to be connected to the glass tube that lights up. Solder a wire to the outer most pins. (we will only be using 2)
It is also a good idea to cover the bottom part of the CFL circuit with hot glue. It seems to prolong the heating of the circuit. To be safe you should not keep it on for longer than half an hour at a time, since it gets quite hot. Wait for it to cool down and then turn it back on again.
These wires will be connected to the flyback transformer in the next step
Step 4: Connecting It All Up
Be careful to put the heat shrink on the wires BEFORE you solder them. You don't really need the heat shrink, but having the extra insulation doesn't hurt.
The wires you just soldered to the CFL circuit...remember those? You should not solder the ends of those wires to the ends of the pair of pins on the flyback with the 1ohm resistance.
Next solder a wire onto the pin that connects to the red wire of the flyback.
Use some helping hands to bring the end of the red flyback wire and the end of the wire you just soldered close together. A few centimeters should do, but they SHOULD NOT TOUCH.
Stand back, hold your fingers crossed and plug the CFL input into a socket.
There should be plasma forming between the red wire and the wire that you put next to it. Now quickly turn it off.
If there was no plasma, try pushing the two wires closer together and plugging it in again.
If there is still no plasma, check if your connections are correct.
If all went perfectly and you got that magical spark of plasma, you can heat up your hot glue gun and put a generous amount of hot glue on the flyback to prevent sparking between the other pins. Just fill up the bottom with hot glue and let it harden for a few minutes.