Film-Tech Forum ARCHIVE: ORC M1000 Lamphouse: Trying to find the cause of sudden failure

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Topic: ORC M1000 Lamphouse: Trying to find the cause of sudden failure

Michael Schaffer
"Where is the
Boardwalk Hotel?"

Posts: 4143
From: Boston, MA
Registered: Apr 2002

posted 09-04-2004 04:54 PM

You can also check that with the multimeter if you check for DC voltage between the lamp cable leads. Normally, you will see the voltage bleed down as the capacitors discharge. Whenever you are unsure if it is safe to touch anything, check for AC and DC between the touching point and ground. Keep one hand away from any grounding points, like the frame.

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Steve Kraus
Film God

Posts: 4094
From: Chicago, IL, USA
Registered: May 2000

posted 09-04-2004 10:52 PM

Note that those big caps are not storing high voltage. But you don't want to get a nasty surprise if you accidentally short one. The voltage won't be high but the oomph (technical term) might weld your screwdriver.

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Mark Gulbrandsen
Resident Trollmaster

Posts: 16657
From: Music City
Registered: Jun 99

posted 09-05-2004 09:50 AM

The voltage won't be high but the oomph (technical term) might weld your screwdriver.
____________________________

I've just been sitting here waiting for a line like this to appear from these guys....... They've been watching far too many Mr. Wizzard reruns lately.....

Now Larry, Before you touch that gizmo you need to open the kneuten valve and let out the oopmh! With these fellows assisting him we will be likley to see other huge technical words such as gizmo, kaneuten valve, whatchamacallit, and firebottle being used freely on this thread....... [Eek!]

What I think Steve meant to use was the word Joules...... [Cool]

Mark

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Steve Kraus
Film God

Posts: 4094
From: Chicago, IL, USA
Registered: May 2000

posted 09-05-2004 10:18 AM

Well, oomph can be measured in Joules, yes.

But you misspelled Kneuter valve.

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Larry Davis
Film Handler

Posts: 66
From: New York
Registered: Sep 2000

posted 09-05-2004 04:29 PM

Guys, re: discharging caps, what do you think of the method advocated here: Safely Discharging Filter Capacitors

quote:
Using a resistor between the postitive end of the cap to ground. It's a very simple tool to make with a pair of insulated aligator clips, some wire and a resistor. I have heard several different sizes of resistors to use. Personally I use a 2 watt 10k resistor as called out in Torres book-Fig 1. Wire it up as shown, make sure the aligator clips have some good insulation on them. As for the wire, I prefer a 600v rating. Which should safely cover most applications. Use a 2 watt 10k metal film or wirewound resistor. That should last longer and be safer in the long run. Make sure to cover any expose wire with electrical tape.

When using this discharger tool, you should hook one of the clips to ground first. Then attach the other clip to the positive terminal of the capacitor. Since the caps are all connected, this should discharge all the capacitors. You'll notice on some designs there is a capacitor on the other side of the Standby switch. Personally I leave the standby switch in the on position to make sure everything drains.

I'd like to know if the idea is sound and if I need other, higher rated components. I have the digital multimeter. I have already tested one diode on another M1000 I have (it is broke and was given to me "for parts"). I do not want to screw this up and I am not going to charge (no pun intended) into this. The two things holding me back are 1) the fear of being electrocuted and 2) the fear of doing more damage to my lamphouse. As soon as I know it is safe to get inside, I will test the diodes. I do appreciate the sincere advice, thanks. No, I did not hear back from the member who offered to explain how to check diodes. At this point, I think it is irrelevant.

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Michael Schaffer
"Where is the
Boardwalk Hotel?"

Posts: 4143
From: Boston, MA
Registered: Apr 2002

posted 09-05-2004 05:46 PM

The power supplies has resistors which more or less quickly discharge the capacitors. When you switch it on and off again, then place the multimeter probes across the lamp connectors or the capacitors, you should see the DC voltage slowly go down. Once it has bled out, you can attack the PS. Just check for AC and DC voltages everywhere you are going to touch to be safe and build confidence. Also remember to switch the breakers to the lamphouse off. You should locate and check the incoming AC wires - someone who worked on the PS before you may have decided to bridge the breakers, I come across that in the field sometimes [Eek!]

Look at the schematic in the manual available from www.film-tech.com and compare it to what you see to familiarize yourself with the components and where they are.

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Mark Gulbrandsen
Resident Trollmaster

Posts: 16657
From: Music City
Registered: Jun 99

posted 09-05-2004 08:21 PM

I want to point out that on some Model 1000's they do not bleed off very fast and can take several hours. Its best to discharge all the caps with a 20 ohm(10K is too high and will take too long to discharge the circuit) 10 watt wire wound resistor before you do anything. If in doubt just take the 20 ohm resistor with some clip leads and place it across the plus and minus lamp leads. This will also discharge anything thats stored in the start circuit. The reason its best to discharge this way is because the 1000 has a seperate higher voltage DC start circuit which is isolated from the lower voltage DC by the blocking diode. Shorting the lamp leads with the resistor discharges both DC circuits [thumbsup]

.

Another word of caution.... don't leave your meter or anything else but the bulb connected to the lamp leads and then try to start the lamp. The high voltage from the ignitor will ruin your meter in just a fraction of a second.

Mark

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Larry Davis
Film Handler

Posts: 66
From: New York
Registered: Sep 2000

posted 09-05-2004 10:24 PM

Thanks, Michael and Mark for the advice. I will keep you posted about my progress. I have removed the power supply from my other lamphouse for practice. But the first thing I will test in the lamphouse I want to fix is the blocking diode. It looks like it is in the right spot for where I saw the flash.

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Steve Kraus
Film God

Posts: 4094
From: Chicago, IL, USA
Registered: May 2000

posted 09-05-2004 11:50 PM

What other self contained lamps have there been and how come no one (to my knowledge) has built a modern one? A lightweight switching supply might make a lot of sense in this situation. Some of the components might already exist for video projectors.

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Mark Gulbrandsen
Resident Trollmaster

Posts: 16657
From: Music City
Registered: Jun 99

posted 09-06-2004 10:37 AM

Check out the viseo threads at www.diyaudio.com and let us know if you find any good light sources the DIYers are using on their home made video projectors.....
Mark

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Steve Kraus
Film God

Posts: 4094
From: Chicago, IL, USA
Registered: May 2000

posted 09-06-2004 05:52 PM

No thank you; I'm not referring to a DIY effort. I mean a manufacturer packing a switching supply right inside a lamphouse. Like an ORC 1000 but lighter. I would imagine it would be somewhat larger too since a more efficent reflector would probably be bigger. Probably not bigger than a 1K or so. Or is there just no demand for something like that? The ORC 1000's still soldier on. Less than ideal for any sort of a permanent installation but just the ticket for portable work. I suppose with quick connectors a two piece arrangement works as well.

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