Here I will show you how easy it is to make a simple high voltage DC crank up generator without the need for fancy transistor flyback circuits such as the famous Joule Thief. This whole thing should not cost you more then $20. In some cases you may already have the parts on hand.
Please be aware that this circuit produces high voltage though not extreem and with a week power source you can feel safe but the shock will make you notice for sure if you do touch the output! Try not to just to be safe and smart. If you feel like experimenting some more with this and use it to charge high voltage capacitors please take some serious caution as the built up charge can discharge in an instant and you could die and have an out of body experience as you watch yourself thrown across the room. Ok so now that the word of caution is over let's get to the fun stuff :)
Step 1: Getting the Parts.
We will need a few parts the make this go should cost less then $20 to make this. The main part is the crank up generator. The one I found was a kids toy flashlight for a few dollars. Some small motors may work as well if you can turn them very quickly somehow. Here is the list of parts needed.
-The Crank up Generator
-Wall AC to AC down converter power supply ( can be found in yard sales or flee markets for very cheep. The lower AC output the better it is )
-Wall AC to DC power supply. ( any small 120 volts AC to 12 volts DC should work. Again can be found in yard sales and flee markets for very cheep )
Step 2: Prepare the Crank Up Generator.
Now it is time to modify the crank up generator. As you can see mine was a flashlight. I took the bulb out and ran two small wires and soldered them inside the connection points where the light bulb used to sit. I taped the wires up around the base to ease off on the tension inside as you can see in this picture. *You may also try some small motors if you have any of those on hand if you can figure out a crafty way to spin them fast it may work.*
Step 3: Connecting the Generator to AC Transformer
In this step we will take our AC-AC transformer. This is an easy task as we don't need to get inside of the AC adapter. We just connect it to the generator.
-Take a took at the power supply. We will connect it in reverse. So chop off the power connector at the end of the wire and strip the tip of the cables. This now becomes the input. So connect the crank power cables to the input cables. The wires have no order + or - as this is still AC at this point.
Step 4: Gutting Out the AC-DC Wall Power Supply
Depending on the power supply you may have to carefully hacksaw the box open. I was lucky enough to have a model that was held together by 4 tiny screws, the whole thing came apart nicely.
We need to gather some parts inside this power supply for our circuit. Here are things to look for and carefully pull.
-Transformer ( We will use this transformer to step up the AC voltage once more )
-Diode bridge ( Every AC-DC power supply has one. It looks like a black square with 4 connection points. Smaller versions may have 4 stand alone diodes close to each other instead. This is the same thing. If that is the case those can be used as well but comes with an extra step if you are not sure what configuration is needed to build a diode bridge )
-High Voltage Capacitor ( Every AC-DC power supply has one. It should be near the diode bridge. The function of this capacitor is to filter out the signal so we can get a good DC compatible signal out of the diode bridge.
Step 5: Your First DC Power Supply!
Now it is time to take our parts from the AC to DC power supply and re build the DC power supply stage of our circuit!
-First locate the diode bridge. Look for the + and - symbols on it. Take those pols and solder them to the capacitor. Take note of polarity and make sure that the capacitor - is connected to the - of the diode bridge!
- The remaining two pols become the AC input.
You just built a basic AC to DC power supply and this model is the foundation of how every one is built!
That's correct all you need now for some clean DC output is an AC source!
Step 6: Putting It All Together Now!
Now it is the time to slap everything together.
-Remember your AC transformer that is just chilling, connected to your crank up generator just doing nothing! Well it is time to connect this to the transformer you pulled out of the AC-DC power supply. Now again we will connect this in reverse. So Where the plug goes from the AC-AC transformer is where on the loose transformer (the pull from AC-DC transformer) I just used tape to keep it all together wrapped the two wires good around the plug polls. Leaving the plug part of the loose transformer free. You may chop the plug and trim the wire tips. Your stepped up AC voltage point is going to be right here!
-Remember that simple AC-DC power supply we built? It is time to connect the output of our loose transformer ( The former wall plug in side ) into the input AC polls of the diode bridge.
Relax that's it we are done!
Step 7: Taking It for a Test Drive
Now we are all done. Depending on parts of course. Your voltage will vary but should be somewhere within this ball park. Go ahead carefully touch your volt meter to various voltage points in this circuit and enjoy the high voltage produced!
I have attached a movie of myself cranking up the circuit and you can see peak voltages of over 300 produced! And slowly notice it lower as the spin from the crank slows down and dies completely finally killing all power generation.