Path: utzoo!attcan!utgpu!jarvis.csri.toronto.edu!mailrus!wuarchive!cs.utexas.edu!uunet!mcsun!sunic!tut!santra!saha.hut.fi!c37189h
From: c37189h@saha.hut.fi (Suomalainen Harri Olavi)
Newsgroups: sci.electronics
Subject: Re: Flash tubes
Keywords: flash, tubes, xenon, strobes, timing lights
Message-ID: <25056@santra.UUCP>
Date: 9 Sep 89 09:12:23 GMT
References: <10919@fluke.COM>
Sender: news@santra.UUCP
Reply-To: c37189h@saha.hut.fi (Suomalainen Harri Olavi)
Organization: Helsinki University of Technology, Finland
Lines: 26

In article <10919@fluke.COM> inc@tc.fluke.COM (Gary Benson) writes:
>    A. What the "bias" voltage is for a typical small flashtube, and is it
>       DC or AC? If AC, what frequency?

Flashtubes need a DC supply of ~100V-500V. When you connect a spike of a few
thousands of volts to the trigger connection (eg. from the spark plug) your
flashtube triggers. You should have your hi-volts energy stored in a capasitor
of 10uF...470uF. After your strobe has been triggered your capasitor (connected
on the stobe) discharges through the flashtube.

>    B. Where I can get a "ballpark" schematic to start playing with,
>       modifying, etc?

There were some shematics in Modern Electronics, July and August 1988.

The most typical circuit is made the following way:

You connect a oscillator to a 6.3V-120V transformer in 'reverse'. At the high
voltage section you rectify hi-volts with a couple of diodes, store energy in
a capasitor and connect the capasitor to the strobe. One end of the capasitor
should be also connected to lo-volts ground connection. You connect the trigger
connection to your spark plug.  You can power a step-up circuit like this
from your car battery.
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