Connect with us

Disco Strobe light to Camera Strobe

Discussion in 'LEDs and Optoelectronics' started by eight08, Dec 7, 2010.

  1. eight08

    eight08

    14
    0
    Apr 16, 2010
    Hey guys. I was wondering if you could help me with my project.

    I have a disco strobe light, potentiometer is at the back, with controls the rate of FPS.

    My question is, is there any way to convert it into a camera strobe, just with 1 shot per trigger? How would i convert it? I was thinking of connecting it to a 1 shot multi-vibrator circuit, 555 timer design. I need it to be fast as in sync with the camera's on board flash.

    Thanks guys!
     
  2. Resqueline

    Resqueline

    2,848
    1
    Jul 31, 2009
    Almost certainly. I don't think you'll need much extra except perhaps for some galvanic isolation for the trigger, since the whole strobe circuit may be at mains voltage.
    Please provide us with a diagram, or at least two good shots (of the pcb, top & bottom).
     
  3. eight08

    eight08

    14
    0
    Apr 16, 2010
  4. Resqueline

    Resqueline

    2,848
    1
    Jul 31, 2009
    I believe all you need to do is remove the diode KV65 and replace it with an optotriac (or a reed relay). Then there is the question how to drive the optotriac with the camera.
    I believe the camera just connects their flash shoe contact to "ground". If so you'll need a small power supply. A couple of penlight batteries would last a loong time.
    Parts: 1 optotriac, 1 resistor, 1 battery holder. Does this sound like a viable solution to you?
     
  5. eight08

    eight08

    14
    0
    Apr 16, 2010
    Thanks for your reply!

    How fast would the reed relay respond? My camera dose not have the hot shoe mount, unfortunately, it it just a bridge type camera with a pop up flash, I was thinking of triggering it with an LDR trigger, to a multivibrator circuit, connected to an SCR, so as the voltage from the multivibrator fires the SCR, the SCR shorts the connection of the strobe. I just need to find the leads in which to connect the legs of the SCR in the strobe. :D

    Oh, and i would like to use the disco part of the strobe too, not totally making it into a camera strobe. Maybe a switch to switch between functions?
     
    Last edited: Dec 8, 2010
  6. Resqueline

    Resqueline

    2,848
    1
    Jul 31, 2009
    Reed relays are quite fast (a millisecond?) but not anywhere near as fast as thyristors (10 microseconds?) and in particular transistors (0.1 microsecond?).
    No need for the opto-triac-isolator if you use an optic trigger. I dont think there's any need for a monostable mvb either, just an LDR and an SCR. I'll try to dig up a circuit.

    Yep, a changeover switch will do fine.
     
  7. (*steve*)

    (*steve*) ¡sǝpodᴉʇuɐ ǝɥʇ ɹɐǝɥd Moderator

    25,206
    2,695
    Jan 21, 2010
    The issue with firing a flash (at least with cameras having a shutter on the film plane) is that you have a very short time to fire the flash -- often only a few thousandths of a second -- that is true even if the sync speed is 1/60 sec!

    I would not recommend any trigger that involves a relay. Admittedly, a reed relay is fast, however an optocoupler is faster, requires less power, and is not significantly more expensive.

    Triggering one flash from another flash is actually a relatively simple problem. There are cheap commercial devices, and the circuit is not difficult.

    There are some examples here, here, here, or here (and there are many more).

    Note that if your camera emits pre-flashes, either to assist focus or for "red eye reduction" then you will have to disable that feature or do something like this.
     
  8. eight08

    eight08

    14
    0
    Apr 16, 2010
    Thanks for your reply guys!

    Thanks Resqueline!
    I built one before, with a solar panel and an SCR which I found in instructables.com, and it worked fine, but upon moving it to a better casing, it suddenly didn't work and I haven't gotten around to that.

    Thanks for your examples (*steve*), but I would like to keep it DIY and keep the cost down if possible. The trigger I guess is not a problem.

    I've built one before, a wireless one using an SCR and LDR at the camera's flash and it synced fine with a little tweaking at a shutter speed of 1/200s. My camera has a manual flash and it emits one burst.

    Those have stopped working and I haven't started troubleshooting as my exams are coming up. Thanks for the help guys!
     
Ask a Question
Want to reply to this thread or ask your own question?
You'll need to choose a username for the site, which only take a couple of moments (here). After that, you can post your question and our members will help you out.
Electronics Point Logo
Continue to site
Quote of the day

-