More Leica Focomat V35 issues-Electrical help needed...

Ok,

Well, the plot thickens a little with my newly acquired Focomat V35...

When I got it, I couldn't get the Focometer 2 to interface with the enlarger...thanks to member
youngrichard, got an instruction manual pdf for the Focometer 2.

NOW, the enlarger bulb (two bulb replacements) burned out...apparently Leica recommend a voltage stabilizer between the Focometer 2 and the enlarger. Upon testing the power at the bulb socket....no power. Yet the Focometer 2 supply to the enlarger tested fine.

I went onto the wiring diagram at bonovolta.ch and his wiring diagram for the V35 shows the voltage selector switch on
the rear is not even wired...? Ultimately, if dedicated to USA 110V, I could eliminate it...I am curious how complicated the wiring is to the lamp...?

Upon opening the base, I ran a meter on the switch and several components and they are hot, but the wires leading from the coil up the column to the lamp have no power... Any suggestions.

Best,
Jason

CropDusterMan said:

I went onto the wiring diagram at bonovolta.ch and his wiring diagram for the V35 shows the voltage selector switch on
the rear is not even wired...? Ultimately, if dedicated to USA 110V, I could eliminate it...I am curious how complicated the wiring is to the lamp...?

Click to expand...

It is not wired because that sample seemingly was a 220V only version, lacking that switch and the respective transformer.

What do you want to eleminate? And what do you want to re-wire at the lamp side?

To me it seems you do not understand the concept of voltage switching and thus are led astray. Be careful.

What version is the sample you yourself got? 110/220V switchable?

Both in the USA as in Europe the mains voltage has risen meanwhile, thus putting higher secondary voltage at the bulb too.

AgX said:

To me it seems you do not understand the concept of voltage switching and thus are led astray. Be careful.

Click to expand...

Hi Agx,
I hear you Mate...
I do understand the concept of voltage switching, I am a certified aircraft mechanic. I realize these
units were cost effectively created for a worldwide market, and thus the voltage selection opens
markets for the items sale on both sides of "the pond" with a single design...just wish I didn't have
to tear into it.

I was hoping to see if someone on APUG had experience with the unit and the problem
I'm experiencing who could perhaps streamline my approach to problem solving.

My observation of the online page mentioned was just an observation. My unit has multi voltage options.

German engineering

The Germans (bless them) had a very large talent in over-engineering things, especially in the olde days. (My ancestors came from Germany, by the way). So I think you have to expect over-engineering. I have an Exacta that has three ways to NOT take photos. And it has a knife inside the camera body. (Can't waste film...) You need to do more digging.

I do not see any overengineering. At that photo refered to even parts are left out/simplified to save a little money.

Ya, I agree...overall, it looks pretty simple...the whole autofocus and such, that's another thing.
I am going to spend a little time troubleshooting it...my experience is that there is usually always
a work-around.

If the Focometer is working fine, then why not find the hot wire that goes on and off according to that device and rewire it from there directly to the bulb? You only need a voltage stabilizer if you are doing long exposures. Are you running it on 220V? It should be easy to bring that down to 110 just for the bulb and let everything else work as planned. If you are NOT getting juice on the side of the component that powers the lamb, the component must be fried. Sorry, I can't be exact, as I do not have any idea what you have, but this is not that complicated EXCEPT that you are dealing w/ alternating current. DC is a lot simpler. Careful w/ 220. I hate that stuff, as it will kill you. If you have any way to convert the enlarger to 110 I would do it.

NOW, the enlarger bulb (two bulb replacements) burned out...Upon testing the power at the bulb socket....no power.

Click to expand...

I can't really follow this. You had two working lamps and they burned out testing the unit? Now you have two burned out lamps and no power at the socket?

Can you post the Focometer instructions or a picture of how have your Focometer configured. It has had european sockets. How did you wire that to your USA 110v enlarger? The output of the Focometer is 110v, yet it has a European 220v socket? Is that correct?

Ultimately, if dedicated to USA 110V, I could eliminate it...

Click to expand...

The last thing I'd concern my self with is modifying the equipment, especially if it is not currently working.

Upon opening the base, I ran a meter on the switch and several components and they are hot, but the wires leading from the coil up the column to the lamp have no power...

Click to expand...

Looks like you may have fried your transformer. What is the voltage on the primary you are measuring? 110/120v? The secondary tabs on the transformer are zero voltage?

The lamp is halogen and is 12V 75W
Am thinking icracer's got it right with the transformer, but if no output to the why would the lamp go?
I'd still clean the snot out of the socket. Might even just replace it.

John Koehrer said:

The lamp is halogen and is 12V 75W
Am thinking icracer's got it right with the transformer, but if no output to the why would the lamp go?
I'd still clean the snot out of the socket. Might even just replace it.

Click to expand...

Jason,
I'm with John and IC Racer ....... I just pulled down my V35 and found the secondary side of the transformer dead. The primary side was ok. The internals of an old transformer, like that one, are simply raw copper wire coated with varnish, to act as an insulator, wound on a ferrite core. This insulator coating is now several decades old and susceptible to flaking off, esp under heat stress - such as arcing at the lamp socket or in a fatal power surge during a filament failure. My solution, here, was to 1) remove the transformer and replace it with the nominated Philips (it might just fit) transformer (from their website) or 2) hard wire or use the existing mains socket in the base for an external 12 v. supply and rewire the lamp side to go directly to the "new" supply (ala Bonovolta's website). This is not to exclude all the usual caveats about electrical safety with fuses and grounds etc. etc. In the end I actually didn't do either of these, as I gave away my unit - 3 too many enlargers here. Good luck and be careful - remember to check unpowered continuity twice across all connections and make sure there is no leakage to the metal chassis and then check to make sure there is no voltage leak to chassis once powered up. I know that 12 volts won't kill you but a short could possibly damage yet another globe. Cheers, Sam

This Triad F220u might work. It is available from multiple sources in the USA. Not sure about the size, however.

Hi guys,

Ok, So here's the deal...I got the enlarger and brought it home...it was basically given to me,
and I did not test it on site. I brought it home and had no instructions.I was confused as to how the
Focometer 2 plugged into the enlarger because there were two identical outlet plugs from the back of the
Focometer to go into a standard computer-style plug. Without instructions, I didn't know which went to the
enlarger?...outlets weren't labelled. I decided to just use another Gralab timer instead...the enlarger powered
on, and away I went making contacts. A half hour into it, the bulb burned out. I had spares, so I changed it.
That one burned out the next day. The unit was set to North American Voltage 110/120.

Now, after changing the bulb again, the bulb won't come on. It is a good bulb. So, I have been trying to tract
down the source of the problem. The socket has no power reading when tested. Testing the transformer when I
get a chance. Thanks for the feedback guys.

Hopefully that clears up the confusion I created.

If the lamp is indeed 12V 75W I would rather get a 12VDC regulated power supply and have a rock solid voltage to the lamp. AC voltage stabilizer are harder to come by. Another the additional advantage is that such a power supply can generally run from 85V to 260V AC 50/60Hz so one doesn't have to worry about the input voltage either.

Furthermore a AC voltage stabilizer not neccessarily lets you chose the output voltage, thus the AC output might still be to high for an old enlarger, letting the bulb run on too high DC-voltage.

Sounds as though you are in a terrible pickle.
I am not clear - I assume you haven't linked the Focometer up to the enlarger yet? If you have then I take it you have a 110v model - mine is 220 v UK model, there is no voltage selector. If you have a 110v version then that is what the output to the enlarger would be, I imagine
My V35 has a 4-position voltage selector on the back of the base, to choose 110, 120 - 130, 220 - 230, or 240 - 250 volts input. I recall that when I acquired the V35 about 25 years ago, I blew a couple of bulbs quite quickly - can't remember if it was wrong bulbs or wrong voltage selected. But it has all gone like clockwork since.
Have you got a V35 manual?
Richard

Hi Richard,

No, I don't have the V35 manual yet, and correct...I haven't been able to link the Focometer 2 yet...have to first get
more bulbs and do more trouble shooting and potentially make a work around.

While you're still trouble shooting, I'd consider adapting 12V automotive bulb to save some &&&.

So call me cheap. I don't care.

I've two spare V35 bases in the garage doing nothing. If you need any spares you're welcome to them...

Tested the transformer on the Focomat V35 and the leads to the transformer from the power switch/voltage selector were fine,
but the two leads out which do to the enlarger lamp are dead. I've contacted Leica NJ here in the USA and am waiting for reply.
The transformer above posted by Ice-racer might work...

Leica New Jersey have been helping with some ideas...the original transformer is no longer available. Big surprise.

Leica told me that it's 24v coming out of the transformer...? I thought it was 12 volt?

I'm looking at the bonavolta.ch rewiring and it looks like a way to go...

The lamp is 12V AC correct? I've had some issues today finding a transformer.