inc@tc.fluke.COM (Gary Benson) (09/08/89)
Hello -- at one time in my life I owned a handbook printed by a manufacturer
of flash tubes. It was a handy little publication, about 50 pages I'd say,
chocked full of interesting info aobut flash tubes. Well, I don't have it
any more, but I wish I did. Maybe someone who reads this group can help.
I have a small flash tube from a camera's flash attachment, and I'd like to
build a small timing light with it. The last time I built one, it was easy:
just followed the schematic in my flash tube book. There wasn't much to it
as I recall -- the spark plug wire went directly to the flash tube's
trigger. But the anode and cathode needed some circuitry between the battery
and the tube, but I can't remember, and being no engineer, have not the
foggiest idea how to design a circuit.
Does anyone have any idea:
A. What the "bias" voltage is for a typical small flashtube, and is it
DC or AC? If AC, what frequency?
B. Where I can get a "ballpark" schematic to start playing with,
modifying, etc?
C. Where I can pick up some hobbyist-level information about flash-tube
circuits. Besides Radio Shack, I mean. They haven't had what I needed
in my last dozen or so trips there.
D. The name of the company who might have published a book such as the
one I just described? Address and/or phone number would be nice too!
Thanks!
--
GaryBenson_-inc@tc.fluke.COM-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_
-_-_-_-_-_-_-_-_-_-_-_-_-_-_-Tell the girls to slice the ham thin -J.C. Penneyc37189h@saha.hut.fi (Suomalainen Harri Olavi) (09/09/89)
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. --- E-mail: c37189h@saha.hut.fi * If you're feeling good, don't * UUCP: ...!mcvax!santra!saha!c37189h * worry - You'll get over it! *