On Tue, 20 Oct 2015 20:01:39 +0100, Ian Field wrote:

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On Monday, October 19, 2015 at 10:04:36 PM UTC-4, Tom Miller wrote:
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On Monday, October 19, 2015 at 2:45:30 PM UTC-4,
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On Monday, October 19, 2015 at 12:53:45 PM UTC-4, Tom Miller wrote:
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On Monday, October 19, 2015 at 9:52:07 AM UTC-4,
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Hi all, I found this thing.. see pictures

https://www.dropbox.com/sh/sxd1cq8qbdyali4/
AAA6O9NqKQPvbX4QLzNAK-Vaa?dl=0
In the back of a drawer at my house. The previous owner was a
pack rat,
who also worked for the phone company.
It looks like some high voltage flashlight.
What sort of voltage do I apply to the leads?

Thanks,
George H.

As per Boris - yes, it could be a timing light - but definitely a
stop-action device of some sort. I expect that there were other
parts associated with it - strobe-type timing lights have an
induction trigger device, usually, as one example. + & -attached
to the battery, and the inductor clamped to #1 cylinder
spark-plug wire.

Peter Wieck Melrose Park, PA

++++++++++++++++++++++++++++++++

But there is no trigger electrode. It might be Neon. Can you hit
it with some high voltage, maybe from a lawn mower spark plug?
See what the discharge spectrum looks like.

Hmm OK, I could try that.

I'm a little leery of mixing electronics with my lawn mower.
Way back when, a motor wouldn't start, and I convinced myself it
was a spark problem. I couldn't see a spark after all. I wanted to
see how much voltage I was getting so I hooked up my DMM (though a
series resistor), Pulled the cord to turn over the engine, and
promptly blew up my DMM. :^(

George H.

Tom, Sorry I chickened out and didn't put it across any of my
working motors. (The last thing I want is to blow out the spark
drive... I'm not really sure, what I'm saying. Is it ok to put a
dead short across my briggs and stratton?

George H.


Doesn't the spark plug do just that when it fires?
Yeah, I didn't say my fear was rational.
I had a bunch of old engines, I think most were "re-cycled" this past
summer.
Hmm, OK I'll hook it up to my old tractor.
(Ferguson to-20) If I blow out the coil it's easy to put in a new one.


What damages magneto ignition systems is open circuit, wire off plug
events.
Then the coil arcs internally.


Don't you have any kind of transformer that could make a HV spark with
say a 9 volt battery? A filament transformer maybe?

9V battery and transformer? (how does that work?)

When you touch the battery across the low voltage winding, it builds up
lines of magnetic flux around the core - when you break the current, the
lines of flux collapse onto the core and induce a high voltage spike in
the big winding.

Most 9V batteries are very low energy density and won't keep up the
current through a low voltage winding - and doing that wouldn't serve
any useful purpose anyway.

Hook one wire of the low voltage winding to one battery terminal, then
hook a loose length of wire to to the other end of the winding and just
flick it on the other battery terminal.

You might get a small back emf spark as you break the primary current,
but you should be able to rig a gap for a half-decent spark from the big
winding.

The coil from a relay might be a better idea than a tranny. Some of those
have a great many windings of fine gauge wire which would put less of a
load on a 9v battery. I've got some here showing over 400 ohms resistance.