Stun gun IC 555?

Hey! i would like to know what the IC 555 does?
i´m really a rookie on electronics so i really need help!

check this link

the 555 is setup in astable mode to make it "pulse" every specified time period (very fast). This must happen because the transformer only magnifies CHANGES of voltage due to magnetic field fluctuations, so you cannot just throw constant voltage to the transformer, you need to throw it lots of short pulses.

good luck

david

Stun gun???

okay thanks alot!!
but I have another question concerning the stun gun schematic by Mark Stoker...
Where is the switch...? how do you controle when you want to chock someone?
(pardon my bad english )