Digital timer for Durst CLS 450?

[gnd2]

I've got a Durst enlarger with the CLS 450 head, STA 450 timer/stabilizer and TRA 450 power supply.

Was wondering if anyone had any ideas for adding a digital timer to this? Hopefully without doing too much hacking.

Doing color separation negs and looking for something more accurate and reliable than the old analog timer circuit. I've calibrated it but don't have a whole lot of faith in it's consistency.

I also like to do split grade printing so having a timer that lets me enter both exposure times and not have to keep adjusting would be nice.

[Drew Wiley]

Isn't that only a 250W colorhead? There are plenty of affordable used Gralab pushbutton timers available which can handle that with sufficient accuracy. With color separations you generally want exposures of at least 10 seconds so that the turn-on and afterglow portion of the cumulative interval, when there is a color shift, is minimal.

[gnd2]

10 sec pft. Enlarging a 35mm slide to 4x5" FP4+ through the RGB filters is getting me around 70 sec at f22-f11 depending on the filter (yes, I have the heads dichro filters switched out). When I move up to 8x10 I'm afraid I may run out of aperture and have to start pushing multiple minutes of exposure :eek:

Yeah, just a single 24V 250W bulb, but how would I integrate the Gralab and keep the power stabilization of the STA? Put it in focus and just power the whole shebang through the Gralab? Does the stabilizer have ramp-up? Put the Gralab between the timer and PS?

The STA has timer and focus footswitch inputs which I've never used, could something be hooked up to that?

[ic-racer]

The STA has timer and focus footswitch inputs which I've never used, could something be hooked up to that?

???

[gnd2]

Oh, I figured it out.

I was assuming the timer input on the TRA 450 was a low voltage control signal. Turns out it's just standard AC so I can just plug any ordinary enlarger timer in to it. That sure makes things easy. I would have replaced the timer years ago if I had known that. Maybe I should find another stabilizer too and get the STA 450 out of the equation altogether.

Now to find a timer. The Gralab might be just the ticket, thanks! Edit: ooh, the Gralab 451 only does whole minute intervals above 99 seconds, that could be a problem.