Single Power Transistor Stepup Transformer

[John Poland]

Just wondering is there any circuits out there or web sites in constructing
a simple oscilating circuit with a power transistor without having to use a
lm555 timer or any other chip just to fire up a ignition coil or a step up
transformer.

Just want to constrct a simple circuit just to test and experiment with
ignition coils or setup transformers.

I know there is circuits out there that use feed back from the coil to fire
the base of the transistor, Iam just after a oscilating circuit that can
swtch off and on to fire the coil.

Thanks John

 

[Eddie]

use a relay with the break contacts in series with the relay coil, and the
make contacts in series with the transformer

"John Poland" <J.poland@ecu.edu.au> wrote in message
news:41cbe88d$0$10037$5a62ac22@per-qv1-newsreader-01.iinet.net.au...

Just wondering is there any circuits out there or web sites in
constructing
a simple oscilating circuit with a power transistor without having to use
a
lm555 timer or any other chip just to fire up a ignition coil or a step up
transformer.

Just want to constrct a simple circuit just to test and experiment with
ignition coils or setup transformers.

I know there is circuits out there that use feed back from the coil to
fire
the base of the transistor, Iam just after a oscilating circuit that can
swtch off and on to fire the coil.

Thanks John

 

[John Poland]

"John Poland" <J.poland@ecu.edu.au> wrote in message
news:41cbe88d$0$10037$5a62ac22@per-qv1-newsreader-01.iinet.net.au...

Just wondering is there any circuits out there or web sites in
constructing
a simple oscilating circuit with a power transistor without having to use
a
lm555 timer or any other chip just to fire up a ignition coil or a step up
transformer.

Just want to constrct a simple circuit just to test and experiment with
ignition coils or setup transformers.

I know there is circuits out there that use feed back from the coil to
fire
the base of the transistor, Iam just after a oscilating circuit that can
swtch off and on to fire the coil.

Thanks John

 

[KLR]

On Fri, 24 Dec 2004 22:41:57 +0800, "Eddie"
<eddie_bounce@optusnet.com> wrote:

use a relay with the break contacts in series with the relay coil, and the
make contacts in series with the transformer

owch

must be a better way than that

but if you insist - I would be putting a capacitor on both sets of
the relay contacts to supress the arcing.

Try searching net for circuits to run Jacobs ladder, plasma ball
displays etc, these will likely use an ignition coil to provide the
EHT, and you can copy the drive circuitry.

SC also did a kit for such a device, but I think it used a 555 based

circuit. as I recall there was plenty of useful advice in that
article too.

"John Poland" <J.poland@ecu.edu.au> wrote in message
news:41cbe88d$0$10037$5a62ac22@per-qv1-newsreader-01.iinet.net.au...
Just wondering is there any circuits out there or web sites in
constructing
a simple oscilating circuit with a power transistor without having to use
a
lm555 timer or any other chip just to fire up a ignition coil or a step up
transformer.

Just want to constrct a simple circuit just to test and experiment with
ignition coils or setup transformers.

I know there is circuits out there that use feed back from the coil to
fire
the base of the transistor, Iam just after a oscilating circuit that can
swtch off and on to fire the coil.

Thanks John

 

[Albm&ctd]

On Fri, 24 Dec 2004 18:02:48 +0800, "John Poland"
<J.poland@ecu.edu.au> wrote:

Just wondering is there any circuits out there or web sites in constructing
a simple oscilating circuit with a power transistor without having to use a
lm555 timer or any other chip just to fire up a ignition coil or a step up
transformer.

Just want to constrct a simple circuit just to test and experiment with
ignition coils or setup transformers.

I know there is circuits out there that use feed back from the coil to fire
the base of the transistor, Iam just after a oscilating circuit that can
swtch off and on to fire the coil.

Thanks John

You can use a power transistor for switching the heavy igntion coil

load but must ensure it can withstand back emf. I've used humble
2n3055s with a diode across them but they don't last long. You could
make a set of mechanical contacts with a small motor, cam and a
microswitch via resistor to the base of the power transistor if you
want to be strange.

Al
Ahh Christmas, the time when big business hearts glow with warmth when they rip you off rather than giving.