Ilex electronic shutter question(s)

Discussion in 'Large Format' started by bob fowler, Feb 6, 2004.

  1. I've been seeing a lot of the Ilex #3 electronic shutters on the big
    auction site. The vast majority do not come with the control box and
    are selling for very little money.

    My question(s): Does anyone know the correct control voltage to the
    solenoid? and: What were the fastest speeds that these were
    physically capable of?

    I have a couple of lenses in #3 Acme Synchro shutters (the set &
    release type, not self cocking). One of them is marked up to 1/200th
    and the other (a newer model) to 1/150th - Both really top out at
    about 1/125th on my tester.

    I went ahead and did a "buy-it-now" on one for $25.00 (including some
    unmarked glass) as a "let's see what this puppy can do" project.
    Making the timing circuit should be very easy, but I'd like to know
    the proper control voltage so I don't fry the solenoid.

    Thanks in advance for any help ya'll can throw my way.
  2. My understanding is that Melles Griot purchased Ilex. Here is what the 1988 Melles Griot catalog says about operating their shutters with customer supplied circuitry instead of with a purchased controller. Probably the same or very similar approach will work with older Ilex electronic shutters.
    "To open the shutter a DC signal four times the rated solenoid voltage should be applied to the bi-post connector for three to five milliseconds. To keep the shutter open, a holding DC voltage of one-half the solenoid rating must then be maintained after opening. Removal of this signal will quickly close the shutter."
    "Standard solenoids are rated at 48 V DC. (Optional ratings of 3, 6, 12 and 24 V DC are available on special order.) Thus the nominal operating signal should be 192 V DC for three to five milliseconds for a standard solenoid, and the holding signal should be 24 V DC."​
    This seems fairly straightforward. The main issue with a used shutter is the nominal solenoid voltage. Probably 48 is the most common value, though it could be that earlier shutters used a different value. Perhaps if you open the shutter the solenoid might be marked with its nominal voltage.
    The catalog has a graph showing the relationship between the electronic control signal and the opening and closing of the shutter blades. The shutter blades begin opening 5 milliseconds after application of the signal and open over a 3 millisecond interval. The 5 ms delay is described as "repeatable and constant" but the 3 ms opening time is described as "a function of both aperture and shutter age, but is neverthess typical. The graph shows the 4X nominal voltage being applied for 8 to 10 milliseconds instead of the 3 to 5 milliseconds described in the text, so probably the exact time isn't critical as long as it is long enough to open the blades and not so long as to burn out the solenoid."
    The Melles Griot shutters have a bi-post connector for flash synchronization. The drawing shows the pins of the sync connector as closer together than the pins of the bi-post connector for the control signal.
    There is a circuit design posted on the web by Georg Holderied: The design is full-featured rather than minimal.
  3. Thanks for the info and link to the controller circuit, it's given me a lot of ideas!

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