Lighting Control

This isn't really much of a question type thread. It's just something I thought I would share with you guys. So my dad has a friend who runs this bar. Their lighting system is out, and now I have it. There are quite a few downsides about this project like the fact that it runs on 240 AC and I don't have a 240 plug in my house that matches it. Also, I have no real starting point. All I know is that it doesn't work. It could be the power unit or the controller. They work together. As far as I know, NOTHING works though. I'm going to do some reading on it. Anyway. I opened it today just to see if I could see anything that was obviously bad with it. Minus being full of spider webs and some components in need of some new heat sink grease, no. Nothing too obvious.

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This is what it looks like. As far as aesthetics go, this is what everything I get looks like, actually. But the case was definitely built tough.

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This is the inside of it. It's fairly basic. No surface mounting which is great. Things will be much easier to test here. Couple of spider webs that the camera doesn't really show. It also smells like stale smoke.

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This was just something I wanted to include as a side note. My last few repairs, I've managed to take something apart and put it back together with absolutely no left over hardware, and this is how. I'm sure this isn't new to some of you, but I always put every screw or bolt back where it went This way it's impossible to overlook some screw holes. It's helped me a lot to keep from losing hardware which was a major problem that I had before. I wish I had thought of this when I took the dashboard out of my car :|

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This is the fan. The flash blanked out the specs on it, but it's a pretty decent size fan. It's a 120 volt fan, so I'll plug it up to a wall socket and make sure it's working before I close everything up.

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Just kind of a reminder of where the fan plugged in.

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A 12 volt regulator. It's supposed to put out 2.2 amps. We'll see...

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Two of these. TRIACS. I just finished a two year electronics program and have no idea how to test a TRIAC.

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I haven't checked to see what the difference between this and the two above it are. I'll read on that after this post.

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Last one.

So that's all I have for now. I'll post some more when I open the controller.

An MC7812CT is only good for ONE amp. Testing a triac isn't easy, you look for an "open" between MT1 and MT2, then you have to bias the gate (which you can do with a second multimeter in the "diode check" range) and look for a low voltage drop across MT 1 & 2. You usually have to do that out of the circuit, so it's usually simpler to just replace the triac if you suspect it (those little TO92 style are cheap).

so it's usually simpler to just replace the triac if you suspect it (those little TO92 style are cheap).

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Those are not the triacs. Thay are the big things mounted to the sides of the heat sinks with the big white wires.

Here is the manual;
https://pdf.textfiles.com/manuals/STARINMANUALS/ETA/Manuals/Archive/1200%20Series%20Dimmers.pdf

Those are not the triacs. Thay are the big things mounted to the sides of the heat sinks with the big white wires.

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The 6-pin MOC3009 chips are triacs (non zero-crossing type).

alec_t said:

The 6-pin MOC3009 chips are triacs (non zero-crossing type).

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Its an opto with a triac output made to drive the big triacs that are mounted on the heatsinks.

Common problems I have encountered with these types of dimmer pack are:

Shorted triacs, which would mean a channel on full brightness and being uncontrollable.
Flickering channel, usually low brightness flickering with no control over light levels.
No output on any channel.
Erratic dimming, usually sets and runs fine for 10mins or so, then jumps to full brightness and back etc.

The first case is easy to identify, find the shorted output triac and replace it, along with the driver opto and bias resistor network.
The second case is less obvious, but is caused by a faulty opto and or bias resistor network. Replace both.
Most easy to identify, no control supply (commonly 10V), the power transformer primary is open circuit.
There can also be a less obvious cause in some dimmer packs, find and test the zero crossing circuit, sometimes an open resistor will hold off the outputs.
The last case is usually a pain to track down, particulary if there are multiple extension leads involved, but it's normally caused by poor connections to the dim controller. Strip and clean all connections between them.

Good hunting :>)