A disappointing beginning

Peter De Smidt · Oct 24, 2005

Ok, so I bought an 810H De Vere enlarger a number of years ago. Last spring, I re-did the basement to accomodate it and installed it. This took months, as the floor was uneven, I had to build an alignable frame to hold the vacuum easel... And I had Tony at Lightwave in London craft me an adapter so that I could use my RH Designs Stop Clock Pro with the enlarger. So tonight I've finally got everything ready. The chemicals were mixed... I plugged in the RH timer and hit focus. Everything came on correctly, and so I focused the enlarger. Next, I changed the timer over to 'test strip' and went to get a piece of paper. When I got back to the enlarger, all of the lights on the Stop Clock were out. I checked the fuse and tried plugging the timer in elsewhere to no avail. Nuts! That was my favorite piece of darkroom equipment. This wasn't a very auspicious beginning for my 8x10 enlarging!

-Peter

jmdavis · Oct 24, 2005

Metronome?

It would work until you have things fixed with the RH time.

Mike Davis

JHannon · Oct 24, 2005

Hello Peter, sorry to hear about the trouble, it must be frustrating. I just have a question. Have you unplugged the enlarger and anything else plugged into the stop clock pro and tried turning it on? Just an idea but something may be loading it down...

--John

Peter De Smidt · Oct 24, 2005

Hi John,

Yep, I gave that a try. Unfortunately no go.

Mike, that's a good suggestion. Unfortunately I don't have a metronome. I do have other timers that I can use, but they aren't f-stop timers. Yeah, I know. I'm really spoiled.

Donald Miller · Oct 24, 2005

It would appear that electrical load design parameters were inadequate.

ChuckP · Oct 24, 2005

Peter,

What do you mean by adapter? Sounds like you will need to use something between the timer and the enlarger. An AC relay is a simple way. The timer controls the relay coil and the enlarger is connected to AC through the relay contacts. You would need the enlarger current to size the relay. Sort of old fashion but simple. Hopefully your timer will be easy to fix.

Chuck

Bob F. · Oct 24, 2005

If you run a computer in the darkroom, the software from here (http://www.bonavolta.ch/hobby/en/photo/fotolab.htm) is useful. The Dry-side software includes an f-stop based test strip calculator. Enter the base (middle) time, the number of steps and the interval in stops (0.3333 for 1/3 stop, 0.2 for 1/5th stop etc) and it will calculate times for each strip. I use my laptop with a red acetate, cardboard and gaffer tape slip-over cover on the screen...

Failing that you can download a PDF of an f-stop exposure table from the writers of "Way Beyond Monochrome" here: (Dead Link Removed).

Cheers, Bob.

Peter De Smidt · Oct 24, 2005

ChuckP said:
Peter,

What do you mean by adapter? Sounds like you will need to use something between the timer and the enlarger. An AC relay is a simple way. The timer controls the relay coil and the enlarger is connected to AC through the relay contacts. You would need the enlarger current to size the relay. Sort of old fashion but simple. Hopefully your timer will be easy to fix.

Chuck

Hi Chuck,

The adapter is simply a cord with a plug on one end that fits into the De-Vere timer plug, and on the other end it has a fixture that the timer plugs into. Lightwave are experts with De-Vere's, and so I'd think that it'd be done properly. It's my understanding that the circuit in the enlarger already contains a relay. I had to replace it when I first got the enlarger to get the head to power on. The enlarger does seem to work ok with a couple of De-Vere timers, but I've lost footswitch capability and F-stop timing. I'll look up some of the f-stop tables.

Thanks, all, for your suggestions.
-Peter

BWGirl · Oct 24, 2005

Hey Peter!

Have you tried emailing the people at RH Designs with this problem? They may have a suggestion or two as well. I guess if the enlarger manufacturer is still around I would emailing them as well.

Hope you get it all working together. I know I'd be lost without my StopClock Pro.

Jim Chinn · Oct 24, 2005

I don't think the timer failure has anything to do with the electrical load if the fuse is still ok. You would have blown the fuse on the timer before any load would have effected it.

Woolliscroft · Oct 24, 2005

Does the enlarger still work without the timer? I know US mains sockets work differently to ours in the UK, but the spur fuse might have gone and we have fuses in the plug you put in the wall. If you do that might have gone.

David.

Peter De Smidt · Oct 24, 2005

Hi All,

Yes, I've emailed RH Designs, and Richard answered promptly. There is a second fuse inside the unit that very rarely blows. Mine did. Hopefully replacing it will be all that's needed to get it running again.

I've been using the enlarger with a De-Vere timer in the meantime, and that seems to be ok, although it's a pain. I've worked out the F-stop timing to do test strips, but it's not fun. The easel is mounted on a wall, and the timer is on the enlarger a step away. That means that I can't simply lay the cardboard on the easel when I change times. I'll have to make some reference marks on the easel. Plus, I really miss having a footswitch!

I don't think I'm going to risk my StopClock with the big De-Vere again.

Donald Qualls · Oct 26, 2005

Remember the old rule of electronics: "A $2.79 transistor will always protect a three cent fuse by blowing first." (okay, it's an old rule, fuses aren't that cheap any more)

JHannon · Oct 27, 2005

Donald Qualls said:
Remember the old rule of electronics: "A $2.79 transistor will always protect a three cent fuse by blowing first." (okay, it's an old rule, fuses aren't that cheap any more)

Very true Donald, I have seen this rule in effect many times. Hopefully it is not a "solder in" type fuse.

--John

A disappointing beginning

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