? on steping up voltage

[Dr.Greenthumb]

What is required to step up voltage from a dc battery to 500+ volts?  How does a stun gun produce a million volt charge just from a 9 volt battery?

[Feynman]

Producing High Voltage DC from Low Voltage DC

suppose input = 12VDC, output = 2000VDC

1) Run low voltage 12VDC into 'inverter' to produce approx 12VAC at 60-10,000hz. The frequency is up to you. An inverter is usually two transistors, two capacitors, and four resistors. It converts DC to AC.
2) Now you take the 12VAC and run it into a step-up transformer to get 480VAC.  (assuming a winding ratio of 40:1)
3) Take your 480VAC and run it into a voltage quadrupler  (basically some HV diodes and some caps) to get 1920VDC.
4) Now you have about ~2000VDC, so you can run it into some filters to make it nice and smooth (optional).

[Dr.Greenthumb]

will a dc-ac converter work? bought a 700 watt one from harbor freight. it puts out 115VAC. When you say a step-up transformer, could the same step up transformer also be used as a step down transformer if hook up the other way around?

[Feynman]

Oh yeah, that'll work perfect.    Just be really careful cause 700watts is a powerful inverter.

So take that 115VAC and run it into a high voltage transformer.  High voltage AC will come out the other side of the transformer.   You can either multiply this higher, or else you can convert it directly to DC.

To multiply higher...
Use a voltage doubler, tripler, or quadrupler.

To go direct to DC...
Use a bridge rectifier to convert the AC back to DC. 

[Dr.Greenthumb]

Awesome thanks for your fast reply. I will have more question as time goes on about electronic components.The class I took at my local college was only for automotive electronics. But it did lead me here! I cant get enough of it all now.