Beseler lamp delay for printing

[Phoebe]

I have just set up a used Beseler 23CII which has the Dual Dichro S colorhead. The problem is that the light does not always pop on as soon as it is switched on sometimes causing a delay of over 1 second. I have tested this both with the enlarger plugged directly into a wall socket and run through two different timers. Again, when the timer is started it may activate the light immediately or be delayed.
The previous owner claims he didn't have this problem and I tend to believe him. I had the enlarger in storage for 2 years before finally setting it up. Any suggestions as to where I can begin troubleshooting?

Regards,
Phoebe

 

[glbeas]

Have you opened the lamphouse and verified the lamp is plugged into its socket securely? Other than that it may be a defective lamp or if you have a voltage stabilizer it may be there.

 

[Les McLean]

Some enlargers do have a delay from when the timer is started to when the lamp switches on. If the Beseler is one of them you need a timer that allows you to set a delay so that it starts with the enlarger.

 

[BWGirl]

You know, mine tends to consistently do this. I start the timer & maybe 1 second later, the light comes on. I have a Beseler 23cII condenser head. I would think that if this is the case, and it's consistent, it should not be a problem. I timed mine against a digital timer to see the lapse & now I just figure the delay into the exposure time.

If, however, this is an intermittent problem, I'd check the bulb like Gary says.
Jeanette

 

[Loose Gravel]

An integrating timer with a light sensor would compensate for this. The MetroLux II even measures the light after the switch is turned off (decay light) and calculates this a part of the exposure.

 

[Phoebe]

Thanks for all your replies re the enlarger delay problem. I will try all your suggestions. I think that the unit is supposed to have its own voltage stabilizer and the directions said not to add an external one. But everything is worth a try.

Phoebe

 

[g.frost]

Hello, I've been lurking here for a while on APUG but when I came upon your post today
I just had to register so I could reply. I have a Dual Dichro with integral power supply
like yours and several years ago mine started to have the same problem. ....Well after
a while it just got much worse until it was unpredictable when and if it would turn on.
I contacted BESELER tech support about the problem and they were most helpful.
There is an 'opto-isolator' in board that goes bad after many years that causes the
problem. As I am handy with a soldering iron and such things, I was able to order the
part from Beseler and replace it myself. (it needs to be removed and replaced on a
curcuit board) As long as the one second delay is predictable you can continue to use
it but I would plan on replacing the part in the near future. Mine has been working fine
since the replacement. (though lately it hasn't seen much use as I'm using another
enlarger) I would recommend to order the part rom Beseler so you have it when the
time comes. Hope you and other Beseler Dual Dichro owners find this helpful.

 

[Phoebe]

enlarger delay problem

Hello, I've been lurking here for a while on APUG but when I came upon your post today
I just had to register so I could reply. I have a Dual Dichro with integral power supply
like yours and several years ago mine started to have the same problem. ....Well after
a while it just got much worse until it was unpredictable when and if it would turn on.
I contacted BESELER tech support about the problem and they were most helpful.
There is an 'opto-isolator' in board that goes bad after many years that causes the
problem. As I am handy with a soldering iron and such things, I was able to order the
part from Beseler and replace it myself. (it needs to be removed and replaced on a
curcuit board) As long as the one second delay is predictable you can continue to use
it but I would plan on replacing the part in the near future. Mine has been working fine
since the replacement. (though lately it hasn't seen much use as I'm using another
enlarger) I would recommend to order the part rom Beseler so you have it when the
time comes. Hope you and other Beseler Dual Dichro owners find this helpful.

I believe that this is exactly my problem. I do need to fix this as there is not a consistent delay. Hopefully Beseler still carries the part.

 

[g.frost]

Phoebe, it's been 5-6 years since I ordered the "opto-isolator" part from Beseler.
I expect they will still be familiar with the problem and have the replacement part but
please follow up here on this thread so others can get their Dual Dichro S fixed.
If you need any details on the part or how to replace it, feel free to contact me.
The opto-isolator goes bad gradually with use: somewhat like a light bulb that gets
darker with age. It is directly related to how long the enlarger light is on. It does not
go bad with storage or non-use.
Good luck, Gary Frost.

 

[Phoebe]

I am in contact with a very helpful person at Beseler. He is trying to help me but Beseler no longer carries parts or does repairs. He hasn't given up yet. I will post to the list when I have solved my problem. I am being optimistic.
Regards,
Phoebe

 

[paul ron]

parts are not made by Beseler... generic replacements?

Electronic parts are generally standard parts since Beseler is not in the electronics business. I suggest you try taking the part out and going to an elecrtonics shop to see if you can find a generic replacement.

OR

Perhaps mr Frost, the part itself has a number and manufacturer as do many electronic parts. If you can open the box and tell me what the name n numbers on the part is, I can look it up for you and the others in my reference books or right here on the internet at Allied Electronics, one of the largest and oldest distributer of parts.

I am sure it's an easy soldering job on the printed circuit board with no more than 4 connections. The opto isolator is to keep one voltage separate from another, to isolate an AC from a DC, higher from a lower voltage or used as a relay. Specs aren't critical as long as we get them within range, current is what kills them.

 

[gainer]

I guess if it were mine, I would look for an optoisolator that has the same pin layout. There are also solid state switches that control AC with a DC signal that can handle well over 3 amps. They have the equivalent of an optoisolator built in.

My advice won't help much if you are not an old, old electronic experimenter. The first article I ever had published was in Popular Electronics in 1960. It told how to build a transistorized automobile radio vibrator using power transistors and an oscillator circuit. Ther's a good chance that most of you don't know what I'm talking about, but in those days, anyone who had a radio in an automobile would have known. Thet were used to convert DC to AC so a transformer could be used to get high voltage for the vacuum tubes. Oh, oh. I used another archaic phrase.

 

[paul ron]

I subscribed then...

What did you publish in PE? What was your pen name? I might still have some of them in the closet.

When I was a kid I would save my 25¢/wk allowence to buy electronic parts from Lafyette on 14th street NYC, or made a regular run to Cortland street to buy parts by the pound form the junk shops to build projects from Popular Electronics Mag. Another mag was Ham Radio which later became Radio Electronics when it turned over to Ziff Davis. Ah yes the dayz when the sweet smell of flux n ozone was in the air. Oh oh don't forget the model glue, my memory is shot... where am i?

 

[mobtown_4x5]

"high voltage for the vacuum tubes. Oh, oh. I used another archaic phrase"

'nuthin archaic about that , brother.. I have 4 12AX7 and 2 EL34 (or something like that) in my class a/b tube amplifier.

For electric guitar, like so many things, the best is always analog.

-Wish I could get one of you ham radio guys to build me some custom tube gear...

Matt

 

[g.frost]

OK, I managed to dig up the old part in a box of parts. The printing on the case is:

"VACTEC 82 12 VACTROL VTL 9B8" the can has 4 leads and about 3/4" high by
about 1/2" diameter. Inside looks like a small neon lamp next to a photo sensor.
Yep, the neon bulb is blackened. Thanks for your help to hunt down a replacement
Paul. If you find something I may order a backup as well.

 

[g.frost]

...Or that could be "VACTROL VTL 988"

 

[paul ron]

waiting for a reply

i found a unit that seems like it should work, it is used in similar applications. I can't find any specs of the or a listing of the number unit you have, so... I e-mailed the companies and am waiting for a reply to see if they list the vactrol we have and if it will be compatable with it.

if I can have someone to measure the voltage/impeadance at the input/output I can better match it. otherwise we are at the mercy of the manufacturer. If I can get a circuit diagram of the unit I can figure it out just as easy. Beseler hasn't answered either. I will call later this week.

 

[Phoebe]

Okay, I have an answer back from Beseler. As folows:

"Yes , you are correct it is an opto-islator and it is marked R2 on the PC board. On the board you will notice a metal piece about the size of a nickel with a cross cut out in the middle. (this was for adjusting voltage) Then you will also notice two silver components that are cylindrical in shape and rounded at the tops. The one to the lower right is the one you would want to change.( the one further away from the plugs that go into the board. Just look at it and I think you will easily find it. It is manufactured by a distributor called Perkin -Elmer and the part # is VTL- 5C3 but it is
different and I am not sure if it has a sequence it must be soddered into the board. Allied Electronics at 800-433-5700 is a company that carries perkin-elmer parts so if you want to give it a shot."

I did check with Allied (they also have a website) who has the part (Allied#980-0710) in stock. The rub is that the part costs $3.00 dollars and the minimum order is $25.00. There is also a company called Newark who carries Perkinelmer parts (773-784-5100). I went with Allied so I can get this fixed. As I am living in Canada I would have preferred a Canadian supplier to make ordering simpler but I could not find one.

As for specs. I believe I came across them on either the Perkinelmer or Allied site.

Will post again when I have the enlarger fixed. I'm taking it to a local electronics outlet.

Regards,
Phoebe

 

[paul ron]

Couldn't wait?

I saw that part you found and sent off an e-mail to Perkins asking if they had specs on the original part vs the one you found, they haven't replied yet.

One other way to get around this is to use a realy that would do exactly the same thing. If I know what the voltage at the input is we can find a coil of matching voltage and pop that in, the contacts on the other side are just for switching no matter what the the current draw is.

There are many other better optoisolators also higher rated and faster, besides, won't die in time as this one seem to do. If you over rate the current carrying capability you may solve a design flaw Beseler was making a nice living from.

You should have posted the fact you needed a minimum order and maybe others could have joined in on the order? Also, I may have been able to get it locally and mailed one to you. NYC still has some electronics parts sources.

Please let us know how it works out?

 

[g.frost]

Phoebe, Please do follow up here and let us know if your part solved the problem.
I presume you ordered extras to 'fill' your $25 minimum order. If that is the case
I would be happy to buy 1 or 2 off you at higher price to help you recoup your
cost. I'm sure there are more than a few others out there with a Dichro 'S' head
that will be needing this part in the future. ...Let's also hope the replacement part
has a longer life span. Good Luck, Gary Frost

 

[paul ron]

I've got an answer from Perkins-Elmer about the Vactrol's specs

I just got an answer from Perkins-Elmer about the VTL9B8 Vactrol. They sent me data sheets for the VTL9 series and another sheet of the newer replacement Vactrol specs.

The Vactrol you have is a neon type, meaning it has a small neon bulb on the AC side of your circuit, your on-off switch... and a photocell on the lower voltage DC side, your lamp regulator circuit. It's main function is to isolate the AC side form the DC side via a light beam on the photocell. When the neon light is "on" the photocell conducts and turns the lamp circuit on. This Vactrol's input is 80Volts AC or 85Volts DC. The newer LED style Vactrols run on 3Volts DC. I have a feeling Beseler used this Vactrol in a 115VAC circuit thus the reason they burn out in such a short time.

There are 2 solutions...

ONE.... Install a really. A really is nothing more than an elecro/mechanical switch. When you turn on your enlarger, the relay's magnet (this would be the AC neon bulb side) pulls a switch closed (where the photocell was in the Vactrol) causing it to conduct, turning on the DC enlarger lamp circuit. This can be soldered directly in place maybe using wire to adapt it to the solder pads of the Vactrol.

TWO... Another more difficult modification would be to use a newer LED style Vactrol. Since they operate on 3volts DC. You'd have to drop the voltage 112volts AC @40ma using a resistor then converting the AC to DC using a voltage regulator circuit. It's not difficult and can be done but... do you want to go to all the trouble?

If you have any questions, e-mail me at automax1@juno.com maybe I can explain it better.

Paul, NYC

 

[glbeas]

Seems to me a third solution would be to tape a neon bulb to a CDS cell of the right value with black electrical tape and solder it in. It would be pretty much the same thing.

 

[paul ron]

If it were mine I would open the little can and replace the neon bulb. How many people will do that? I suspect most just want to purchase a replacement part. It sucks that Beseler wouldn't repair it with some retro fit part knowing this is a problem.

The relay would be the cheapest way to go. I did see an article about a way to make your own Vactrols but they were LED style.

Do you have this same enlarger? Can you measure the voltage at the vactrol's neon lamp? Is it AC or DC?... Does the voltage keep the neon hot all the time and peaks at breakdown voltage? If you can get me some more info I can look up neon bulbs as a way to replace the burnt out one.

 

[g.frost]

Hello Paul and thanks for all the time and effort you have put into this issue.
I have the Dual Dichro 'S' head and will open it up and take the voltage measures
for you. Right now it is packed away and not being used so it may take a few days
to get around to it. I did take a dremel to the failed part and open it up. The idea
of replacing only the neon bulb looks feasible. If I recall, the halogen lamp in this
enlarger is 82 volts, so they have to step down from 115 somewhere in there.
I'll post back here when I get it out and take the measures. Thanks again! Gary

 

[paul ron]

What to measure...

If you are going to measure the voltages, what is important is the voltage accross the neon bulb when the box is idle and in the turned on mode. I assume the timer turns this on and off but the voltage stabilizer is on the entire time.

Then measure the voltage on the photo cell side to see if it has an idle and on state voltage. If there is an idle state which keeps the circuit hot at a standby voltage it will have to be shunted in, the realy will just have to add the difference to bring it up to working voltage.

It is a shame these units will become trash if there is no easy fix. Perhaps I may be able to get buy one broken for $50 now?

I wonder what ever happened to the other person that got a part? That part has an LED adn will cook as soon as it is turned on.

Let me know when you have the measurements?... e-mail em to me at automax1@juno.com

Paul, NYC