From: Thorfirstname.lastname@example.org (P!erCer)
Subject: Ignition Coil Power Supply Final Question
Date: 13 Jan 2003 10:54:57 -0800
NNTP-Posting-Date: 13 Jan 2003 18:54:58 GMT
I have built my supply, a 555 timer/Dual 2N3055 configuration that
pulses power at regular intervals down my feed wire.
It was based on this config, but has two 2N3055s and two coils:
There are many BIG ASS DIODES between the 2N3055s and the coils that
protect from backpulses. The coils are hooked up in anti-parallel, so
that the pulse from the 2N3055s goes into the negative on one and the
positive on the other. The other side of the coil is grounded. From
what I understand, since I am feeding the coils with pure DC and not
allowing any sort of back flow, the output will be a very high
positive voltage on one coil and a very high negative voltage on the
other, depending on the polarity of the magnetic fields, which should
be opposite because of the way I hooked the coils up. One coil will
always be the positive, while the other will always be negative, and I
should get a long pulsed DC spark from on to the other. I do still
have some questions, however.
In the coil, when the magnetic field collapses, is high voltage only
produced at one end? I would think that high voltage would be
produced at both ends and sent back through the ground wire too...but
it isn't. Why?
I can see no way this config is going to produce AC, but then again
this project was basically the third electronics thing I've built. I
appreciate the people on this forum who know what they are
doing...this will be DC, right?
And a last quick question:
For the 2N3055s, I should connect the positive to the emitter, the
pulse from my signal generator to the base, and the output to the
casing of the whole thing, which is the collector. Right? Why the
hell did they make the CASE the collector instead of just a third pin?
Couldn't that be dangerous, if you mount a metal heatsink on it and
then somebody touches it to see if it is hot? I do things like that.
If more semiconductors are like this one, it worries me.
Thank you for your time,