Film-Tech Forum ARCHIVE: Orc rectifier, hard striking

This is topic Orc rectifier, hard striking in forum Film Handlers' Forum at Film-Tech Forum ARCHIVE.

To visit this topic, use this URL:
https://ft-forum.com/ft/cgi-bin/ubb/ultimatebb.cgi?ubb=get_topic;f=1;t=011078

Posted by Dominic Espinosa (Member # 2122) on 11-07-2011, 06:13 AM:

Hey gang,

Just wanted a second opinion before going forward and it's 4AM...doubt my favorite tech pal would appreciate a text this early [Razz]

We had a single-phase orc take a dive a while back with a bad diode.
I replaced all the diodes and the lamp will strike and run a show but there's one little thing.

When the lamp lamphouse is set for automatic ignition, flipping on the lamp results in the igniter firing but not lighting the blub.

If I switch it to manual, turn on the lamp, and then wait a second and hit the manual ignition button it strikes just about as it should.

My theory is the ignitian capacitor is dying, possibly damaged from the bad diode.
Before going ahead with any more repairs I thought I should run it by the brain trust first...Thoughts?

Posted by Louis Bornwasser (Member # 3063) on 11-07-2011, 07:29 AM:

The time element in this makes me think the main power supply capacitor is marginal. Louis

Posted by Tony Bandiera Jr (Member # 2365) on 11-07-2011, 06:36 PM:

Step 1: Disconnect the ORC rectifier.
Step 2: Toss it in the dumpster.
Step 3: Get a real rectifier from a manufacturer that is still in business. (Strong, LP assoc., Christie)
Step 4: Install said rectifier.

Problem solved.

With all the 35mm equipment being pulled you should have no problem finding a replacement for little or no cost.
[thumbsup]

Posted by Mark Gulbrandsen (Member # 72) on 11-07-2011, 06:53 PM:

What Tony said. I have a garage full...

Posted by Louis Bornwasser (Member # 3063) on 11-07-2011, 08:11 PM:

Yeh, guys, that was my first response, too. I reconsidered when I thought that he may need a single phase AC source, making that old, worthless unit slightly valuable.

I would have gotten rid of the ORC back in 1973. Louis

Posted by Ian Parfrey (Member # 5122) on 11-07-2011, 09:44 PM:

Dominic.

How is the spark gap looking? I had one of these things do similar hi jinks and the spark gap was the culprit. Replaced it with an adjustable Kinoton one and no more dramas.

Posted by Tony Bandiera Jr (Member # 2365) on 11-07-2011, 10:11 PM:

Louis:

Depending on wattage, there are plenty of single-phase rectifiers out there..LP Assoc. makes a magnetic one,. Strong has a switcher good for IIRC up to 2.5k, Christie had a few also.

Ian:

Good point..and a cheap and easy fix. [thumbsup]

If it were up to me though I'd still dump that ORC crap. [puke]

Posted by Dominic Espinosa (Member # 2122) on 11-11-2011, 04:20 AM:

Well looks like logic wins this one.

The transformer burned up right nice.

Who wants to sell me one?

Posted by Tony Bandiera Jr (Member # 2365) on 11-11-2011, 01:30 PM:

Dominic:

What wattage lamp are you running?

Do you have 3-phase power available in your booth?

I will cut you a screaming deal on the LP assoc. rectifer I have, it has about 7 hours total run time on it. (see my listing in the equipment forum...disregard price you see there).

We can discuss possible delivery and installation. (By PM of course.)

Posted by Dominic Espinosa (Member # 2122) on 11-11-2011, 02:13 PM:

Tony, I appreciate that offer!

Lamp is 1600 watt. To make 3 phase id have to run wire and switch out a breaker.

Posted by Gordon McLeod (Member # 33) on 11-11-2011, 03:52 PM:

check the alumium plate that makes the bridgeing of the caps it often has corrosion over time

Posted by Tony Bandiera Jr (Member # 2365) on 11-11-2011, 04:53 PM:

Dominic:

Can your lamphouse handle a 2k bulb? That is the lowest setting on the rectifier I have.

And the add a wire.change breaker may not be a big deal, get a pic of your breaker panel for me and send it to my email.

Gordon:

Sir, sorry to break it to you, but did you read Dominic's post, the one two posts above yours? The transformer is burned up so I think it's beyond repair.

Posted by Dominic Espinosa (Member # 2122) on 11-11-2011, 05:41 PM:

Tony, sort of...It's an old Cinemechanica console. We're running 2k's in the same model at another theater.
The caveat though is that the projector mounted on it is a Century with a modified mount and the 1600 is actually too close to it as it is, scorches the #@$! out of it.

In March or so we have a location closing and that screen becomes a side-by-side, so I'll be able to salvage a nice LP to put behind it but until then...

Gordon, I checked that plate. We burned a wire off of it last year on this same machine.
I should take a picture of the carnage when I get back down to the theater. The xformer, aside from putting out ~ 2 volts has an obviously burnt, blackened lead coming out of the windings. One that is barely holding on as a matter of fact!

Posted by Mark Gulbrandsen (Member # 72) on 11-12-2011, 02:40 PM:

quote: Gordon McLeod
check the alumium plate that makes the bridgeing of the caps it often has corrosion over time

Ditto for the connections to the heat sinks. I went though that with CFS (actually LP Associates) rectifiers a couple summers ago.

Posted by Tony Bandiera Jr (Member # 2365) on 11-23-2011, 01:32 PM:

Mark, the ONLY thing that CFS rectifiers had in common with the LPA was the design. IIRC it was, parts-wise, a complete knock-off of the LP unit. I have NEVER had any such failures on LP rectifiers. Only the occasional random diode opening up.

Posted by Gordon McLeod (Member # 33) on 11-23-2011, 02:41 PM:

I was once told that leonard pincus (LP of the LP associates) Ron Offerman and dick nicum all were with ORC and went there seperate ways and that the transformers were all LP designed

Posted by Richard Fowler (Member # 893) on 11-24-2011, 07:30 AM:

Leonard should be the last of the ORC boys. Last saw him driving his sports car,stopping by Norms restaurant at La Cienega Blvd in Los Angeles, for a midnight snack a few years ago.

Posted by Dominic Espinosa (Member # 2122) on 11-28-2011, 04:27 PM:

Well it turned out we have an old irem that will do 1600w so I swapped the breaker and added a leg. Now just waiting on the capacitors to come in; we salvaged some off this unit to keep another screen going.

Its funny. I never wanted anything to do with power supplies or drive trains really.