EEVblog Electronics Community Forum
Electronics => Projects, Designs, and Technical Stuff => Topic started by: psxpetey1 on December 09, 2023, 10:20:07 pm
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So my project is this triggering a 100v old style pc sync flash using a tlp127 in between it and the camera.
I connected a power source to anode 1.2v 10ma and cathode to ground and the pc sync positive to collector and negative to emitter.
I assume that once I connect the source the tlp would send the collector voltage to emitter to trigger the flash.
But it doesn’t trigger.
Data sheet: https://www.mouser.com/catalog/specsheets/Toshiba-TLP127.pdf (https://www.mouser.com/catalog/specsheets/Toshiba-TLP127.pdf)
Can someone help me out
This was the guide for the camera I was following : http://www.sx2pc.com/ (http://www.sx2pc.com/)
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The TLP127 is very slow to switch, 50µs turn-on time, so maybe its not fast enough to trigger the pulse transformer in the flashgun?
This is probably a consequence of it being a photo-darlington rather than plain photo-transistor output.
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The TLP127 is very slow to switch, 50µs turn-on time, so maybe its not fast enough to trigger the pulse transformer in the flashgun?
This is probably a consequence of it being a photo-darlington rather than plain photo-transistor output.
well this is a very very old flash over 1 minute to charge from 1974 Honeywell strobnar 100. My next idea is to try a led on the emitter to see if the tlp works maybe it’s broken I have extras but ya maybe they do have a flash list on the old page. I have used a constant power source as well so it should turn on and eventually fire the flash you would think.
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That may be the problem I guess I’ll have to open the flash and see what it’s got going on in there I tested it with a led and the tlp was working. With a power source. Funny that the tlp with a constant power source for the led on the collector emitter won’t trigger that led either so maybe like you said the turn on time is too slow maybe 🤔. In his old project he used triacs for high voltage and the tlp for low voltage flashes I guess I’ll have to do some more research and maybe buy a flashbar just to double check my sx70 flash ability as well. Any suggestions for faster photocouplers