Time-O-Lite Discovery

Vaughn

Subscriber
Joined
Dec 13, 2006
Messages
10,192
Location
Humboldt Co.
Format
Large Format
I take care of the teaching darkroom for a university. I have been having the enlarger bulbs blowing on me right and left on one of my banks of Beseler 23C enlargers for the past couple years. Sometimes several a day, then a long break. I was buying the bulbs 24 at a time several times a year. I had our electrician to put a voltage recorder on the curcuit, etc.

But I think I discovered the problem this morning. I checked all the Time-O-Lite timers (Masters and Pros) and found one that throws about 400 to 500 volts back into the supply line just as it shuts off. So if someone on the same curcuit has their enlarger light on while this beast shuts off, it might be blowing the bulb with the power spike.

Now the timer is engraved HSC and then a inventory number. The university changed its name from HSC to HSU in 1973...so this beast is at least 35 years old. I suppose it is amazing that it still works at all after 35 to 40 years of constant use (I have others of the same vintage that still work fine, and the back-up timer I put in its place is of the same vintage).

Any electricians out there that might confirm my suspecions about the timer? The way I measure it was to put the timer on a two out-let extension cord. Plugged in the timer to one of the out-lets and put the meter's probes in the other...and watched the needle jump from 110V to about 500V as the timer shut off.

Vaughn

PS...the next question is if it is worthwhile to send it back to the factory to be repaired ($75 to $100 is the average repair bill, as per the company).
 

Mike Kennedy

Member
Joined
Feb 5, 2005
Messages
1,594
Location
Eastern Cana
Format
Multi Format
I have the same timer as a back up.Stumbled on a digital (pardon the lingo) Gralab last summer.Fantastic.
IMO it wouldn't be worth your while to have it repaired.Maybe bronze it as a keepsake for it has served you well.
 
OP
OP

Vaughn

Subscriber
Joined
Dec 13, 2006
Messages
10,192
Location
Humboldt Co.
Format
Large Format
Our other timers are Beseler Digital timers...they are alright, but I have to send them in for repairs regularly. We have 19 enlarger stations, 125 to 150 students per semester, and besides the class times, about 75 to 80 hours of open darkroom time a week. Those buttons get pushed a lot! And often with wet fingers.

I am afraid the Gralab digitals would not hold up to the punishment.

Vaughn
 

ath

Member
Joined
Aug 29, 2006
Messages
844
Location
Germany
Format
35mm
The timer might not be defect, it might just be the way it works. You might want to put an overvoltage protector / supressor on the powerline of the enlargers.
 

Craig

Subscriber
Joined
Apr 8, 2004
Messages
2,366
Location
Calgary
Format
Multi Format
Vaughn said:
I am afraid the Gralab digitals would not hold up to the punishment.
Click to expand...

They are surprisingly tough, we had one in my highschool yearbook darkroom and it never gave any trouble. Considering how cheap they can be bought these days if it lasts 3 years and then you replace it, its probably cheaper then changing bulbs.
 

dpurdy

Member
Joined
Jun 24, 2006
Messages
2,680
Location
Portland OR
Format
8x10 Format
I nailed one of those timeolite timers to the wall of the studio for timing polaroids. Great for that.

For the darkroom the Beseler Audible Repeating timer is hard to beat.
 

Chan Tran

Subscriber
Joined
May 10, 2006
Messages
6,923
Location
Sachse, TX
Format
35mm
What kind of heads do you have in your Beseler 23? I think the high voltage surge is not coming from the time-o-lite but rather the 23C which has a power supply.
 
OP
OP

Vaughn

Subscriber
Joined
Dec 13, 2006
Messages
10,192
Location
Humboldt Co.
Format
Large Format
Ath -- I checked all our Time-O-Lites...it was the only one that sent a spike of high voltage back into the curcuit...I don't think it is suppose to do that (and I don't want any computer equipment on the curcuit either! LOL! The other Time-O-Lites gave no indication of any spike of any size...no movement of the needle of the voltmeter. But your idea of putting surge protectors on the enlargers is an interesting one. If the problem continues without the spiking timer on the curcuit, I'll give it some thought...though 8 surge protectors would not be cheap either.

Dpurdy -- that is actually the Beseler timers we have. Good timers but the print buttons fail eventually in a teaching darkroom -- pressed too hard sometimes hundreds of times a day! And occasionally the contacts of the knobs used to set the times fail. And they are also $75 to $100 to repair.

Vaughn
 

dpurdy

Member
Joined
Jun 24, 2006
Messages
2,680
Location
Portland OR
Format
8x10 Format
You could go old school and get a metronome. When I was in school at Glen Fishback in the 70s they had one Beth and Thomas metronome (you wouldn't want two) for the darkroom. Tic Tok Tic Tok Tic Tok. Everybody counts the seconds. To this day I count the beeps on my Beseler Audible. No one complained about the tic toc in school, but it was annoying that one guy would hum a tune in time.
 

PHOTOTONE

Member
Joined
Oct 30, 2006
Messages
2,412
Location
Van Buren, A
Format
Large Format
dpurdy said:
You could go old school and get a metronome. When I was in school at Glen Fishback in the 70s they had one Beth and Thomas metronome (you wouldn't want two) for the darkroom.
Click to expand...

I think you mean a SETH THOMAS (brand) METRONOME. Quite a common brand for Metronomes and for Clocks.
 
OP
OP

Vaughn

Subscriber
Joined
Dec 13, 2006
Messages
10,192
Location
Humboldt Co.
Format
Large Format
A metronome...isn't that a little funny looking guy, but all sort of modern...you know, a well dressed gnome?

Have you been in a darkroom full of 18 to 22 years olds lately? Either they have their iPods sticking in their ears or they have the CD player cranked up...no one will be able to hear a metronome (or a retrognome).

Chan...some of these 23C's are as old as the timers...all condenser heads...nothing but the light bulb in there.

Vaughn
 

BradS

Member
Joined
Sep 28, 2004
Messages
8,124
Location
Soulsbyville, California
Format
35mm
Vaughn,

Interesting discovery. I have an old Time-O-Lite P-59 that, I swear, has a mind of its own. Seems to work fine, if a bit noisy, most of the time but every once in a while, it just kinda goes berserk! I wonder...?
 

Deckled Edge

Member
Joined
Jan 25, 2004
Messages
446
Location
Manhattan Be
Format
8x10 Format
Vaughn said:
Good timers but the print buttons fail eventually in a teaching darkroom -- pressed too hard sometimes hundreds of times a day!

Vaughn
Click to expand...

The circuit board is not well supported near the print button, and the board begins to flex. Eventually no circuit when you push PRINT. I had to insert a little block of wood behind the board to bolster the support. Works again.
 
OP
OP

Vaughn

Subscriber
Joined
Dec 13, 2006
Messages
10,192
Location
Humboldt Co.
Format
Large Format
Deckled Edge said:
The circuit board is not well supported near the print button, and the board begins to flex. Eventually no circuit when you push PRINT. I had to insert a little block of wood behind the board to bolster the support. Works again.
Click to expand...

Thanks DE...I'll haul out the 8 or so Beseler timers I have awaiting funds for repair and see it that works on some of them! I am all out of back-ups, and no money to send any off until the next budget cycle.

Brad...I notice one enlarger not getting much use, so I checked it out -- the timer buzzed like a banshee. Probably had the students wetting their pants when they made their first test strip! I removed it from the darkroom, but haven't checked that one to see if it tosses out a few more volts than it is suppose to.

Vaughn
 

Nicholas Lindan

Advertiser
Advertiser
Joined
Sep 2, 2006
Messages
4,275
Location
Cleveland, Ohio
Format
Multi Format
Deckled Edge said:
The circuit board is not well supported near the print button, and the board begins to flex. Eventually no circuit when you push PRINT. I had to insert a little block of wood behind the board to bolster the support. Works again.
Click to expand...

That can also indicate a cracked trace on the circuit board or a cracked solder connection. The block pushing the board back up pushes the cracked bits together so they make contact again. It's a very common failure mode.
 

Nicholas Lindan

Advertiser
Advertiser
Joined
Sep 2, 2006
Messages
4,275
Location
Cleveland, Ohio
Format
Multi Format
Vaughn said:
Beseler timers ... the print buttons fail ... the contacts of the knobs used to set the times fail.
Click to expand...

That was what drove me into the timer buisness -- opening up a failed Beseler timer to fix it and deciding there was a problem here that needed a much bigger fix.
 

Mike Wilde

Member
Joined
Aug 10, 2006
Messages
2,903
Location
Misissauaga
Format
Multi Format
Electrical engineer speak follows

when a motor shuts off, all of the magnetic field (that causes the motor to spin) that was being created by the electric field collapses. Since the electric field was shut off, it is now able to take back energy that the magnetic field wants to dump. The magnetic field in most motors does not decay gradually, so the electriclk field does not absorb that magnetic energy gradually. It takes it in all one fast whump.

A capacitor placed across a contact that shuts off a motor usually does the job of absorbing that 'whump' and storing the all at once energy, and then bleeding it out over a longer period fo that it is not so disruptive.

I suspect that there is an open circuit 'squelch' capacitor in the offending time o lite. Replacing it, if this is the case is likely a 1 hour and $2 in parts repair.
 
OP
OP

Vaughn

Subscriber
Joined
Dec 13, 2006
Messages
10,192
Location
Humboldt Co.
Format
Large Format
Thanks Mike. That probably entails soldering and all that fancy stuff, LOL! We'll see if I undertake such a project...electrical/electronic wimp that I am! I'd probably have to open the timer up and take in down to the next town's electrical/electronic supply store and ask them to point out the "open circuit 'squelch' capacitor" and see if they have one in stock. (and probably ask how much they would charge to replace it).

If only my electrical engineer brother-in-law didn't live 800 miles away!

Vaughn
 

srs5694

Member
Joined
May 18, 2005
Messages
2,718
Location
Woonsocket,
Format
35mm
Vaughn said:
If only my electrical engineer brother-in-law didn't live 800 miles away!
Click to expand...

You could mail it to him. If he'd fix it for free, two-way postage would still be cheaper than an official repair.

Another option: Since this is a university darkroom, there must be faculty, staff, or even students who are capable of doing such a repair pretty near by. You might be able to barter the repair for a couple of hand-made enlargements or get it done inexpensively in a university-run shop.
 

MattKing

Moderator
Moderator
Joined
Apr 24, 2005
Messages
53,624
Location
Delta, BC Canada
Format
Medium Format
Vaughn said:
Have you been in a darkroom full of 18 to 22 years olds lately? Either they have their iPods sticking in their ears or they have the CD player cranked up...no one will be able to hear a metronome (or a retrognome).

Vaughn
Click to expand...

For some reason, when I read the suggestion of a metronome, I thought you ment one metronome per enlarger.

The image in my mind of a group darkroom, complete with a cacophony of metronomes, is somehow completely disturbing .

Matt
 
You must log in or register to reply here.
Menu
Log in
Register
Cookies are required to use this site. You must accept them to continue using the site. Learn more…