Comments for Projects :: NoSomos http://projects.nosomos.org Because we like doing it ourselves Tue, 13 Dec 2011 10:14:31 +0000 hourly 1 http://wordpress.org/?v=3.1.1 Comment on Flash trigger by helen http://projects.nosomos.org/flash-trigger/comment-page-1/#comment-58 helen Tue, 13 Dec 2011 10:14:31 +0000 http://nosomos.org/projects_wp/?page_id=56#comment-58 could you explain in more details how did u connect the arduino to the camera ? could you explain in more details how did u connect the arduino to the camera ?

]]> Comment on Camera and flash trigger module by Richard http://projects.nosomos.org/2009/03/camera-and-flash-trigger-module/comment-page-1/#comment-56 Richard Fri, 11 Nov 2011 19:11:58 +0000 http://nosomos.org/projects_wp/?p=21#comment-56 Love the article. I'm having issues getting the flash trigger to work, though. The voltage across the hot shoe leads seems to overwhelm the opto isolator and leave the circuit closed, regardless of the input on the input on the other side of the opto. Any thoughts? Love the article. I’m having issues getting the flash trigger to work, though. The voltage across the hot shoe leads seems to overwhelm the opto isolator and leave the circuit closed, regardless of the input on the input on the other side of the opto. Any thoughts?

]]> Comment on Ambilamp video! by Anonymous http://projects.nosomos.org/2009/09/ambilamp-video/comment-page-1/#comment-2 Anonymous Wed, 20 Jan 2010 18:49:29 +0000 http://nosomos.org/projects_wp/?p=30#comment-2 Are you planning on putting the specs up anytime soon? :) I'm very curious about this project. Are you planning on putting the specs up anytime soon? :)

I’m very curious about this project.

]]> Comment on Flash trigger by Anonymous http://projects.nosomos.org/flash-trigger/comment-page-1/#comment-5 Anonymous Sun, 10 Jan 2010 19:50:33 +0000 http://nosomos.org/projects_wp/?page_id=56#comment-5 How can too high a voltage damage the octocoupler? Every octocoupler Digikey sells offers at least 1500V isolation. How can too high a voltage damage the octocoupler? Every octocoupler Digikey sells offers at least 1500V isolation.

]]> Comment on Flash trigger by admin http://projects.nosomos.org/flash-trigger/comment-page-1/#comment-6 admin Sun, 10 Jan 2010 15:07:52 +0000 http://nosomos.org/projects_wp/?page_id=56#comment-6 Well, I guess that voltage isolation means that if you put more than 1500V in the input, current can jump to the output, so there is no more isolation between them. For example, a 4N29 optocoupler is rated for 5300 Vrms for input-output isolation voltage. But 1.5V max for Vf ("forward voltage", that is voltage applied to the photodiode in forward way) and 80mA max for If ("forward current", that is, current passing through the photodiode in forward way). Higher values than 1.5V or 80mA in the input will break the optocoupler but current will not jump to the output. I guess that if you use an older flash, with higher trigger voltage, it can fry your optocoupler, but the discharge won't be enough to reach the arduino, <strong>but I cannot take responsability if that ever happens.</strong> <strong>Use at your own risk!<strong> Well, I guess that voltage isolation means that if you put more than 1500V in the input, current can jump to the output, so there is no more isolation between them.

For example, a 4N29 optocoupler is rated for 5300 Vrms for input-output isolation voltage. But 1.5V max for Vf (“forward voltage”, that is voltage applied to the photodiode in forward way) and 80mA max for If (“forward current”, that is, current passing through the photodiode in forward way). Higher values than 1.5V or 80mA in the input will break the optocoupler but current will not jump to the output.

I guess that if you use an older flash, with higher trigger voltage, it can fry your optocoupler, but the discharge won’t be enough to reach the arduino, but I cannot take responsability if that ever happens.

Use at your own risk!

]]> Comment on Flash trigger by admin http://projects.nosomos.org/flash-trigger/comment-page-1/#comment-8 admin Mon, 23 Nov 2009 19:58:35 +0000 http://nosomos.org/projects_wp/?page_id=56#comment-8 Yes, in fact there was a pin mismatch between the code and the schematic, should be solved now. Thanks for finding it :-) Yes, in fact there was a pin mismatch between the code and the schematic, should be solved now. Thanks for finding it :-)

]]> Comment on Flash trigger by Anonymous http://projects.nosomos.org/flash-trigger/comment-page-1/#comment-7 Anonymous Sun, 22 Nov 2009 19:55:41 +0000 http://nosomos.org/projects_wp/?page_id=56#comment-7 Great work, and thanks! It seems to me that there is a pin number mismatch between the code and the schematic. Great work, and thanks!

It seems to me that there is a pin number mismatch between the code and the schematic.

]]> Comment on Flash trigger by Anonymous http://projects.nosomos.org/flash-trigger/comment-page-1/#comment-14 Anonymous Sun, 18 Oct 2009 08:44:14 +0000 http://nosomos.org/projects_wp/?page_id=56#comment-14 Regarding high-voltage flashes, there is no problem as long as you use a suitable optoisolator. Digikey has SCR and triac output versions that can handle 400V for less than $1. Regarding high-voltage flashes, there is no problem as long as you use a suitable optoisolator. Digikey has SCR and triac output versions that can handle 400V for less than $1.

]]> Comment on Flash trigger by Anonymous http://projects.nosomos.org/flash-trigger/comment-page-1/#comment-13 Anonymous Fri, 15 May 2009 08:43:07 +0000 http://nosomos.org/projects_wp/?page_id=56#comment-13 Without any knowledge of electronics, I copied your circuit. (Thanks to you and Glacial Wanderer for the great detail!). I got everything working except that I could not get the optocoupler to trigger the flash. In fact, I was frying the oc! I was using an old flash unit;- many of the older flash units have a big trigger voltage, too high for the optocoupler. (There is a site which shows the trigger voltage of most strobe flash units;- http://www.botzilla.com/photo/strobeVolts.html). In the end I replaced the oc with a relais (Zettler AZ473-2CB-5DE). It's a shame about the speed loss due to the relais but the circuit works now, even with my old flash unit. Adrian Without any knowledge of electronics, I copied your circuit. (Thanks to you and Glacial Wanderer for the great detail!).
I got everything working except that I could not get the optocoupler to trigger the flash. In fact, I was frying the oc!
I was using an old flash unit;- many of the older flash units have a big trigger voltage, too high for the optocoupler.
(There is a site which shows the trigger voltage of most strobe flash units;- http://www.botzilla.com/photo/strobeVolts.html). In the end I replaced the oc with a relais (Zettler AZ473-2CB-5DE). It’s a shame about the speed loss due to the relais but the circuit works now, even with my old flash unit.
Adrian

]]> Comment on Flash trigger by Anonymous http://projects.nosomos.org/flash-trigger/comment-page-1/#comment-9 Anonymous Fri, 15 May 2009 08:38:00 +0000 http://nosomos.org/projects_wp/?page_id=56#comment-9 Laser pointers are very delicate. It is very important to respect the exact voltage and polarity of the unit. Adrian Laser pointers are very delicate. It is very important to respect the exact voltage and polarity of the unit.
Adrian

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