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#1
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Another question
Sorry that I am being such an annoyance, but I have another question. I dont
want anyone to go through the trouble of providing an entire circuit. In fact I want to do it myself. I just wanted to be pointed in the right directions. What parts do I research, etc. Anyway, here is the problem. I want to electronically trigger a photo flash of unknown trigger voltage. The flash provides the voltage. The circuit simply needs closed to fire the flash. But here is the trick. Photo flashes, especially older ones, have a wide range of trigger circuit voltages. At the low end it could be only 3.5v. On the high end it could be 300v. I have 3 flash units. (3.5v, 15v, and 55v) Although I read that there are a few old units that go 100v and higher. Much above 5v can be death to a modern electronic camera. So I want to make a circuit such that I can use any of mine, and maybe other, flash unit with a electronic camera. (Either mine or a friend's.) So, what kinds of componets do I research that can give me the ability to trigger a flash with a range of 3.5 to, say, 100v? I have done a search and found high voltage transistors that can handle 200v (collector to emitter) but still only need 5v at the base. Someone has mentioned looking into something called an SCR. That same person suggested an opto-isolator for best possible protection of the camera. What about a voltage regulator? (I might be using someone else's $1000+ digital camera, so I want to be extra carefull. Last thing I want to do is to return to them a fried camera.) I have found sites discussing the theory of some of these components, but they dont really give the practicle trade-offs as to when you might want to use one verses another. Again, I am not looking for an exact circuit, just an idea what to best spend my energy researching. Thanks in advance, Henry |
#2
Posted to alt.electronics
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Another question
"Henry" wrote in message
om... Sorry that I am being such an annoyance, but I have another question. I dont want anyone to go through the trouble of providing an entire circuit. In fact I want to do it myself. I just wanted to be pointed in the right directions. What parts do I research, etc. Anyway, here is the problem. I want to electronically trigger a photo flash of unknown trigger voltage. The flash provides the voltage. The circuit simply needs closed to fire the flash. But here is the trick. Photo flashes, especially older ones, have a wide range of trigger circuit voltages. At the low end it could be only 3.5v. On the high end it could be 300v. I have 3 flash units. (3.5v, 15v, and 55v) Although I read that there are a few old units that go 100v and higher. Much above 5v can be death to a modern electronic camera. So I want to make a circuit such that I can use any of mine, and maybe other, flash unit with a electronic camera. (Either mine or a friend's.) So, what kinds of componets do I research that can give me the ability to trigger a flash with a range of 3.5 to, say, 100v? I have done a search and found high voltage transistors that can handle 200v (collector to emitter) but still only need 5v at the base. Someone has mentioned looking into something called an SCR. That same person suggested an opto-isolator for best possible protection of the camera. What about a voltage regulator? (I might be using someone else's $1000+ digital camera, so I want to be extra carefull. Last thing I want to do is to return to them a fried camera.) I have found sites discussing the theory of some of these components, but they dont really give the practicle trade-offs as to when you might want to use one verses another. Again, I am not looking for an exact circuit, just an idea what to best spend my energy researching. Thanks in advance, Henry Henry Use an optical isolator See http://dkc3.digikey.com/PDF/T053/1570-1571.pdf choose one with Vceo greater than 200V It isolates your trigger signal from the flash and if you connect the plus wire from the flash to the collector and the minus wire from the flash to the emitter it should act like a switch which closes when you put current thru the optocal isolator diode Dan -- Dan Hollands 1120 S Creek Dr Webster NY 14580 585-872-2606 www.QuickScoreRace.com |
#3
Posted to alt.electronics
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Another question
"Dan Hollands" wrote in message ... "Henry" wrote in message om... Sorry that I am being such an annoyance, but I have another question. I dont want anyone to go through the trouble of providing an entire circuit. In fact I want to do it myself. I just wanted to be pointed in the right directions. What parts do I research, etc. Anyway, here is the problem. I want to electronically trigger a photo flash of unknown trigger voltage. The flash provides the voltage. The circuit simply needs closed to fire the flash. But here is the trick. Photo flashes, especially older ones, have a wide range of trigger circuit voltages. At the low end it could be only 3.5v. On the high end it could be 300v. I have 3 flash units. (3.5v, 15v, and 55v) Although I read that there are a few old units that go 100v and higher. Much above 5v can be death to a modern electronic camera. So I want to make a circuit such that I can use any of mine, and maybe other, flash unit with a electronic camera. (Either mine or a friend's.) So, what kinds of componets do I research that can give me the ability to trigger a flash with a range of 3.5 to, say, 100v? I have done a search and found high voltage transistors that can handle 200v (collector to emitter) but still only need 5v at the base. Someone has mentioned looking into something called an SCR. That same person suggested an opto-isolator for best possible protection of the camera. What about a voltage regulator? (I might be using someone else's $1000+ digital camera, so I want to be extra carefull. Last thing I want to do is to return to them a fried camera.) I have found sites discussing the theory of some of these components, but they dont really give the practicle trade-offs as to when you might want to use one verses another. Again, I am not looking for an exact circuit, just an idea what to best spend my energy researching. Thanks in advance, Henry Henry Use an optical isolator See http://dkc3.digikey.com/PDF/T053/1570-1571.pdf choose one with Vceo greater than 200V It isolates your trigger signal from the flash and if you connect the plus wire from the flash to the collector and the minus wire from the flash to the emitter it should act like a switch which closes when you put current thru the optocal isolator diode Dan -- Dan Hollands 1120 S Creek Dr Webster NY 14580 585-872-2606 www.QuickScoreRace.com That simple huh? ANd I was getting ready for this complex circuit. Thanks, Henry |
#4
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Another question
Decide which voltage flash unit you would like to use first. Then go from
there. |
#5
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Another question
deadcarnahans wrote:
Decide which voltage flash unit you would like to use first. Then go from there. Looking at your lack of context over several posts, I would have sworn you were a newbie posting from Google Groups --nope--you're just a newbie who is otherwise unschooled. FYI: http://66.102.7.104/search?q=cache:8...give-a-context |
#6
Posted to alt.electronics
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Another question
"JeffM" wrote in message oups.com... deadcarnahans wrote: Decide which voltage flash unit you would like to use first. Then go from there. Looking at your lack of context over several posts, I would have sworn you were a newbie posting from Google Groups --nope--you're just a newbie who is otherwise unschooled. FYI: http://66.102.7.104/search?q=cache:8...give-a-context Not at all. Just a person who is doing too many projects than I have time and resources for. Henry |
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