HowTo: Build a flash trigger

This content has moved to http://swannman.github.com/flashtrigger/.

46 Comments

  1. Posted August 28, 2006 at 10:35 am | Permalink

    Thanks Matt for walking through explaining “how does it work” – that was really really useful to me.

  2. Posted August 28, 2006 at 10:37 am | Permalink

    You’re very welcome! Let me know if any part of it is confusing — I know there are parts of the explanation that are still a bit rough.

  3. Posted August 28, 2006 at 10:47 am | Permalink

    Very nice tutorial, I look forward to building my own.

  4. Dave
    Posted August 28, 2006 at 11:42 am | Permalink

    Any chance of a parts list? I know its all there in the text, but a simple list would be helpful.

  5. Posted August 28, 2006 at 12:29 pm | Permalink

    I’m happy to oblige! I’ve added a parts list at the end of the article.

  6. Posted August 28, 2006 at 2:06 pm | Permalink

    Pardon my ignorance…
    This will be my first blind leap into constructing a circuit based on a schematic. I’m assuming that Every point labeled as “Vcc” is where the 5 volt power connects? Second, I’m a bit confused as to the symbol between pin 3 on the 555 and and pin 1 on the 4743a. Thanks for your time. We all have to start somewhere, right?

  7. Posted August 28, 2006 at 3:16 pm | Permalink

    Those are both great questions! Yes, the 5v output from the MAX603 is what all the pins labeled Vcc connect to.

    The symbol between the 555 and the 7473 is just a visual aid to demonstrate that the line is normally low, but will go high for a certain amount of time, then go low again. It’s similar to the symbol above pin 2 of the 555 — which notes that the line is normally high but pulses low.

    Neither of those symbols are an industry-standard, but they helped me remember what’s going on. Hope I was able to shed some light on the issue!

  8. Posted September 1, 2006 at 8:15 pm | Permalink

    ha ha, me again. A trip to the local radio shack yielded a ton of different npn and pnp transistors. What should i be looking for? Thanks again.

  9. Posted September 1, 2006 at 9:52 pm | Permalink

    Any of them should work — we don’t need transistors with a high beta for this project.

  10. Posted September 8, 2006 at 6:42 pm | Permalink

    Nice tutorial and explanation of circuit–despite me being lazy and not really saying anything about it. One good idea is to use diode lasers rather than IR diodes since this gives very precise triggering and easy adjustment of sensitivity.

  11. Posted September 8, 2006 at 8:32 pm | Permalink

    Using diode lasers is an excellent idea. I hadn’t done the research to find out what all was needed to drive them, so I took the easy route — but that would definitely improve this circuit.

    Thanks for the suggestion!

  12. Mike D
    Posted September 17, 2006 at 2:04 am | Permalink

    First of all, good job on the tutorial. Second, my flash would not trigger using the suggested relay. I have an old Vivatar flash I bought in the 1970′s. I ran across this website, http://www.carlmcmillan.com/Optoisolated_Adapter.htm which uses an SCR to trigger the a flash. I had an old 2N4171 SCR in my junk box and hooked it up to the outputs of your relay circuit in the manner shown in the above article. It worked. Probably has something to do with the lower on-state resistance of the SCR or not.
    Thanks for the tuturial.

  13. Posted September 17, 2006 at 8:11 am | Permalink

    Glad you were able to get it to work!

  14. John S
    Posted December 30, 2006 at 12:50 am | Permalink

    I thanks posting your circuit and for such a clear explaination of how it works. I was wondering if there is way to modify your circuit so that the flash fires when a common red LED turns on as opposed to when an infared beam is broken? I would like to be able to point a detector at an LED and have the strobe trip the moment the led lights up.

  15. Posted December 30, 2006 at 7:57 pm | Permalink

    Hi John,

    The photodetector listed for this circuit might work as-is, depending on what kind of light is put out by the red LED. Otherwise, you’d need to find a phototransistor that responds to red light — I suspect those should be in ready supply at Digi-Key, Jameco, and the like. Let me know if you find one that works well!

    Cheers,
    Matt

  16. skibum_11
    Posted March 19, 2007 at 4:49 am | Permalink

    please i need your help im not good at electronics but im learning
    i like the way you wrote the explination it really helps,
    here is my problem i need to build a lightning trigger
    im currently in Iraq and i will be in storm seaso shortly unfortuanaty the Schematics i have i have been unsuccesfull could you please look over the schematics and make recomendations first circuit
    http://www.technick.net/code/cp_dpage.php?aiocp_dp=cir_solorb_lightning
    does not fire i think one of the problems is the one of the leads from the 4047 is going to +- power the one im most concerned about is pin 8 the schematic i attach my trigger to my cam with a remote cord
    the second is http://www.astro.uni-bonn.de/~kbagshi/blitze.shtml

    Thanks in advance
    btw i can call or be called i have a US based number

  17. Posted March 19, 2007 at 7:53 am | Permalink

    The schematic at http://solorb.com/elect/lightning/ looks like it should work just fine — I don’t see anything wrong with it…

  18. mike
    Posted November 23, 2007 at 4:38 am | Permalink

    This is very nice tutorial.

    But I’m completely useless with that. Would you build it for me?

    I want to use it with D70 Nikkor and sb600

    Regards
    MIKE

  19. bryan
    Posted December 12, 2007 at 7:02 pm | Permalink

    I love the circuit, having problem locating the PVA33. Any ideas where I can find it or an equivalent.

  20. Posted December 12, 2007 at 11:58 pm | Permalink

    Hi Bryan-

    Any normally-open solid-state relay should work. It doesn’t need to be able to handle a great deal of current.

    Hope that helps!

  21. Ernie Simpson
    Posted January 17, 2008 at 1:52 pm | Permalink

    I have a couple questions about your flash trigger circuit.

    1. Is the 3.3k resistor value critical or could I use a 5k instead without problems?

    2. On the same part of the circuit is that diode a regular LED or is it another type of diode?

    Other than that I just want to say thanks for putting this information out there for other photographers to use.

  22. Posted January 17, 2008 at 2:08 pm | Permalink

    Hi Ernie – a 5K resistor should work fine, and yes that’s a regular diode. That part of the circuit pulls the reset pin low for a brief moment when power is applied.

    Hope that helps!

  23. naveen
    Posted July 3, 2008 at 10:27 am | Permalink

    nice tutorial…
    but i have some doubts…
    can we use 7805 ic which outputs 5v instead of MAX 603??
    and also can we use an opto coupler insted of PVA33N solid state relay??

  24. Posted July 3, 2008 at 10:31 am | Permalink

    Yep, that should be fine.

  25. vijay shamrao kamble
    Posted July 12, 2008 at 4:33 am | Permalink

    your ckt is good.
    can you send the clap triggered ckt? please

  26. quoc
    Posted December 8, 2008 at 8:16 am | Permalink

    frineds,
    I have built a kit using this intrusction. However, I do nto have consistent triggering. SOmetime, I got good triggering all the time, sometime, I got few about of 50 drop. Does IF sensors require certain drop requirement such as speed, aceleration, liquid transparency ??
    Please advise
    See my website for the one I took : http://www.flickr.com/qnguyen4490

  27. Posted December 8, 2008 at 10:09 am | Permalink

    Those photos are gorgeous, Quoc! Nice work.

    How are you making the droplets? I found that the most common reasons for the circuit not to fire were

    a) the emitter and detector aren’t aligned

    b) the droplet didn’t pass exactly between the two

    c) there’s excess light getting to the detector (when the drop falls, other light still keeps the detector turned on)

    d) the variable resistor on the detector isn’t tuned correctly (you want to adjust it until just the slightest interruption in the beam causes the circuit to trigger)

    I found that adding some heat-shrink tubing around the emitter and detector helped — it meant they could only look straight ahead, so it was obvious when they weren’t aligned right and the detector couldn’t pick up ambient light from the surroundings.

    Does it trigger consistently when you pass your hand between the emitter and detector? If (a)-(d) above are correct, this should work every time.

  28. quoc
    Posted December 9, 2008 at 8:05 am | Permalink

    Matt,
    If I use notebook AC adapter to power the kit ( current range is from 3v-12V, is that a problem ?

  29. aditya
    Posted December 9, 2008 at 8:03 pm | Permalink

    hi matt…
    it’s very nice of you to make this circuit availaible…
    m not very gud at elecronics..
    so can u pls mail me the PCB…if u can so that it will be easy for me to get the work done….
    thanx in advance….
    tk cre…

  30. confizzled
    Posted December 13, 2008 at 1:26 pm | Permalink

    hey , I’m new to this kind off stuff so i didn’t completely understand all of it but it was still a good tutorial. being new i have no idea how to convert a schematic to a design for a PCB so if you could post one i could print with eagle cadd that would help a lot. im fairly confident i can take it from there. one more thing id like to have the transmitter and receiver fairly far apart ( 5 ft or so ) and ive seen a set up using a laser and a solar panel type thing…. how ever i have no clue what alterations this would require….

  31. Posted December 13, 2008 at 2:43 pm | Permalink

    @aditya/confizzled –

    Your best bet here might be to purchase a breadboard and assemble the circuit there… once you have that working, you can recreate it on a pre-printed PCB that has similar traces.

  32. Russ
    Posted February 6, 2009 at 5:52 pm | Permalink

    Do you have a PC Board layout for the trigger and power supply?
    Do you have a way to trigger the flash from a flash mounted on the camera with out wiring?
    Do you have a way to trigger the flash from a sound?

    Gread info.

  33. Posted February 7, 2009 at 11:02 pm | Permalink

    I don’t have a PCB layout… if I remember correctly, I soldered this on a prefab board that had traces approximating a breadboard.

    I haven’t built a wireless trigger system.

    You should be able to trigger it from sound if you replace the light trigger circuit with a microphone and wire it such that sound produces a dip in voltage.

  34. new kid
    Posted April 8, 2009 at 7:06 am | Permalink

    hey i have an automatic camera. would this work with that. and please mail me the PCB if possible

  35. Posted May 24, 2009 at 11:12 am | Permalink

    Mat, great schematic. After some time, and some modifications because I use some sifferent components, I got it all working. But what I wonder, how big is the maximum gap between the LED and the phototransistor, I can reach about 2 inch max. But my feeling is it should possible to have a larger gap, so it would allow bigger object to pass through.
    Thanks!!
    Patrick

  36. Posted May 25, 2009 at 5:57 pm | Permalink

    Patrick, you’re very welcome! Two inches sounds about right from what I remember… you could replace the detector with a Darlington phototransistor, those have a second transistor that acts like an amplifier to add some gain — it could probably pick up the emitter from farther away.

    Nice work!

  37. Posted May 26, 2009 at 9:33 am | Permalink

    Matt
    Thanks for the swift reply. I’ll see when I have some time to change it to increase the distance. Meanwhile I added a sound trigger as input detection, I already notice that youreally need the delay for breaking/falling object ;-)
    Great fun to work with, although my workbench gets rather messy by object falling into liquids…
    Give a shout if need the sound trigger schematic.
    Best regards

    Patrick

  38. oddgeira
    Posted June 15, 2009 at 9:34 am | Permalink

    can this be triggered by sound. If yes how?

  39. oddgeira
    Posted June 15, 2009 at 9:36 am | Permalink

    sorry, i didn’t read the whole post.

  40. Jim
    Posted August 24, 2009 at 6:34 pm | Permalink

    Hi, nice strobe layout. Do you think that it also could be used as a simple slave flash (triggers with a camera flash?) Im looking for a delayed flash.

  41. Bradford Beidler
    Posted October 7, 2009 at 6:30 pm | Permalink

    Awesome, thanks for sharing.

  42. Posted February 1, 2010 at 5:46 am | Permalink

    “me really agreed with this project…”
    myself a b.tech 2nd year student…
    while working on projects then …

    we find ur ideas which hepls us to come in front…
    to do something….!!!
    thanks “sir”
    “MOHSIN
    DEEPAK JHA
    KAPIL GOURH”

  43. sayali pradhan
    Posted February 4, 2010 at 6:27 am | Permalink

    hii matt
    i hve never workd on a project yet..into my 2nd year..found ur ckt interesting..cud u plz mail me its pcb diagram..thanks in advance..

  44. anjum
    Posted March 13, 2010 at 1:53 am | Permalink

    iamfirst time trying to do project,urs is an intresting one.iam a be second year student.sir plz send me details ,circuit diagrams ,pcb diagrm and total cost it wud be as soon as possible.sir kindly do the need. i vl b thankful 2 u.

  45. Joshua Gonzales
    Posted September 5, 2010 at 4:54 pm | Permalink

    hello i was just wondering if you knew any cool projects that have two inputs ant two outputs. I have a class project coming up soon and i was just wondering if you had any pointers, or where i could find a good project. Thank you

  46. prab
    Posted September 26, 2010 at 5:19 am | Permalink

    i have new idea from this circuits thanks

11 Trackbacks

  1. By How to build a flash trigger « BotHack on August 29, 2006 at 12:09 pm

    [...] http://swannman.wordpress.com/2006/08/24/howto-build-a-flash-trigger/   [...]

  2. By links for 2006-08-30 « Donghai Ma on August 29, 2006 at 9:23 pm

    [...] HowTo: Build a flash trigger « Movin’ to Seattle (tags: electronics hardware photography tips reference tutorial) [...]

  3. By Making headway « Movin’ to Seattle on September 11, 2006 at 7:27 pm

    [...] I’m nearly finished moving my flash trigger circuit from the solderless breadboard on which it came to life to a more permanent surface… [...]

  4. [...] Check it out! [...]

  5. By Finished! « Movin’ to Seattle on September 24, 2006 at 2:35 pm

    [...] The last knob for my flash trigger project came in this week — so it’s finally finished! [...]

  6. By Gummi splash « Movin’ to Seattle on October 14, 2006 at 8:05 pm

    [...] One evening I set up my flash trigger and spent an hour or so dropping gummi bears into a dish of water… [...]

  7. [...] Well here’s a cool little cat detection and repellent device using a sprinkler controller and some timer delay circuits.  I think there’s a lot of timer delay circuits, especially the 555 being used for a lot of these DIYs, but I think it would be easier to do with BASIC controllers… OR you can probably just buy a ultrasonic rodent repellent for under 40 bucks. But that would really take fun out of life if you could buy everything out of your life… [...]

  8. By British Wildlife Forums - does anyone remember on January 21, 2007 at 1:49 pm

    [...] simple and could be made much cheaper than the commerical product. This site has alternatives and this site has a simple flash trigger circuit Kev Lewis http://www.photosbykev.com It’s not who you feel that [...]

  9. By Color coded « Movin’ to Seattle on February 22, 2007 at 11:32 pm

    [...] comic is particularly amusing for anyone who’s ever spent hours looking up resistor [...]

  10. [...] — this is the guy whose electronics work and XBox hacking got me seriously thinking about dabbling in electronics [...]

  11. [...] något eget. Tex beskriver Johannes Eriksson hur han gjort här. Matt Swann beskriver sitt bygge här. Här var också en bra sammanställning av lite olika trigger [...]

Follow

Get every new post delivered to your Inbox.