Re: LM555 as a Astable Multivibrator help!!

pranthony@xxxxxxxxxxx wrote:

Hello
The basic circuit I am using is at this link:
http://i9.photobucket.com/albums/a60/phil54/lm555circuit.jpg
The resistors are set at 470k and the caps are .1 uf. This gives me a
10Hz
pulse.

Here is my problem I need help with.I am wanting to use this to pulse
the neg.post of a ignition coil to groundcoil to ground.,( to cut
ignition in and out to add it shifting).Now my problem is this circuit
pulses positive.
I can soldier and put things together but when it comes to designing
something like this I am lost.
Can someone give me some help here.
Thanks

that's good that it does.
use that signal to drive a NPN transistor in common emitter mode.
use a decoupling resistor of course so not to over drive the tranny.
the collector should be on the - side of the coil.
P.S.
you mite want to have a small cap from the - side to common other
wise, you mite be seeing your tranny in semi after life land.
there are other ways like, not allowing the tranny to go into
cut off? etc...



--
Real Programmers Do things like this.
http://webpages.charter.net/jamie_5

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