timer circuit?

Discussion in 'Camera Building, Repairs & Modification' started by John Koehrer, Mar 12, 2010.

  1. John Koehrer

    John Koehrer Subscriber

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    1)I'd like to have a timer or circuit that would allow for longish exposures AND activate a solenoid to depress a cable release. having a display would be nice but a VR would work & I could put reference marks on a holder of some sort.

    2)For the room of darkness a pair of timers, the first one actuating the second.
    Again a display & separate controls would be nice.

    3) Golly, it would be nice if the solution were simple & available at Radio snack, but I can work with perf board & point to point wiring
     
  2. ic-racer

    ic-racer Member

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    Before I get to #1 above, a possible easy solution for #2 would be to plug the second Graylab timer into the safelight output of the first Graylab.
     
  3. ic-racer

    ic-racer Member

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    Just thinking on #1 that there would be thousands of timing options but for the Solenoid for a large format shutter, I'd look for a Horseman setup. They made a nice little solenoid that ran from a 22V battery. They made these into the 90s and they frequently show up on ebay.


    Here is another solenoid a little bigger and not a pretty as the Horseman one:
    http://www.siliconchip.com.au/cms/A_30322/article.html
     
    Last edited by a moderator: Mar 12, 2010
  4. Mike Wilde

    Mike Wilde Member

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    If you are starting from scratch, look up 555 IC's. They are the swiss army knife iof integrated circuit timers chips.
     
  5. Nicholas Lindan

    Nicholas Lindan Advertiser Advertiser

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    If your skills extend to programming there is the http://www.arduino.cc/.

    There are libraries of software for driving LCD displays and keyboards. Lots of companies make accessories for the Arduino. There are several boards like it for the hobby robot crowd.

    555's are just so steam-punk.
     
  6. unclemack

    unclemack Member

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    Hi, programmable multi-input/output process control from a pc isn't that expensive these days. These people (others too I'm sure) sell a stand-alone unit that may suit you. I think it's their "Hawk" model. Choice of output devices via relays or s/s.
    http://www.pc-control.co.uk/
    For the darkroom the Jobo process timer 4 works well for me, cost about £15 used - 4 sequential timers, hit button to start next timer. No time display though. Have a paterson triple timer too, 3 timers run concurrently, also OK and with lcd display x 3 but smallish buttons.
    Or did you mean an enlarger timer?
     
  7. John Koehrer

    John Koehrer Subscriber

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    Thank you all.
    So far cascading the Gralab may be an instant solution.

    Looking at the beginning of the article with the solenoid(can't get the rest w/o buying it), will it accept a timer of some sort to activate it?

    An electronic stop watch or timer with an output for a relay would be neat. That would give me the ability to use the solenoid & control it with the watch.

    I guess it would be nice to be portable too.

    I'll check out the Jobo timers too, that may be more elegant but not necessarily more efficient as I already have the Gralabs.
     
  8. Chan Tran

    Chan Tran Member

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    John, you need the timer to activate trip the shutter of a large format camera?
     
  9. Chan Tran

    Chan Tran Member

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    I was thinking and I think it would be easier to use an air can and solenoid valve to operate the bulb type shutter release cable. I would get a timer from Red Lion Controls. Run the whole thing on 12V battery.
     
  10. John Koehrer

    John Koehrer Subscriber

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    Well, I've found a load of timers with output for relays. Not very expensive either. Now it's time to roll the dice & see what happens.
    Chan, that sounds good too. I've got a pneumatic plunger on a small bulb so I'll take a look at Red Lion.
    One of my problems is almost anything I do is going to look cobbled together. The Red Lion might make the cleanest install.
    Thank you.
     
  11. Chan Tran

    Chan Tran Member

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    John, since you live near me I think I have things around the house that can make for you what you want. Let me know.
     
  12. unclemack

    unclemack Member

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    Hi, thought of this when I first awoke this morning. Guess why?
    Record your voice on an MP3 player announcing elapsed time every 10 seconds or so and any reminders you wish for each step of a given film's process and name the file for the film, eg. "FP4 id11 push one.mp3" - just press play to start.
    That way if you need to pee (not exactly in the first flush of youth myself if you must know) you'll be back in time even if you have to stop...erm...mid-stream :-(