Bese;er Dichro45 and Gralalb 545

[Kilgallb]

I have a Besler Dichro 45 and a Gralab 545 timer. The timer works perfectly with my old D2 enlarger. With the Dichro 45 head the light is on all the time when plugged into the timer. The timer can be off or on, no difference.

I suspect the 545 timer switches neutral instead of hot.

Has anyone else had this problem with the Dichro45 and the Gralab 545?

 

[glbeas]

That Dichro runs way more wattage than the D2. Are you sure it didn't fry the contacts in the 545?

 

[Bob-D659]

This page has the connection diagrams, http://backglass.org/duncan/darkroom/beseler_dichro_45_head.pdf

Is yours hooked up the same way? Also is the timer plugged into the same circuit as the enlarger? The timer is controlling a power relay in the head, and is only supplying a control voltage, it is not switching the main power to the bulb itself, if you are connecting everything properly.

http://www.gralab.com/pdfs/545.pdf if you don't have the manual for the timer.

UL labs don't like switched neutrals, so I doubt it, unless someone replaced the power cable/end on the timer.

 

[joh]

I have a Gralab 450 timer, it works very well with all my enlargers and heads
except with my Aristo VCL 4500. The VCL has a power relay too, and it needs very little
energy to switch the lamp on...it seems to little energy for my Gralab timer.
The Gralab lets the time run off, jumps to the starting point and lets time run off again,
and again...and again...
I noticed, that if i put a second electrical part to the power outlet from the Gralab,
so that more energy must be switched, it works without any problems.

 

[Kilgallb]

Thanks for the suggestion. It worked. (I used a safelight for the test load)

 

[joh]

maybe a simple resistor between timer and head will do the trick too.
I have not tested it till now...