Hi

This is my first post here

I'm repairing an old light controller. It works via the speaker output of an amplifier, and via some very basic circuitry it dims the lights (bass middle treble) with the music as input.

However, due to a faulty power cord the treble stopped working after a big spark came out at the back of that plug (it shorted I think, there are just three wall outlets on the back of the device to plug your lights in (240V).

I can't see any damage on the pcb itself, so I think it this triac that is causing the problem (BTA10-700B). The rest are just resistors and diodes. However, this traic I need isn't available anymore. I only have basic knowledge of electronics, so I don't know what all the specs mean in the datasheet.

Could someone please help me find a modern alternative to this old one? I've managed to find the datasheet for it, I've attached that to this post. I've also included some pictures of the controller itself. There used to be three build in plugs, however, someone replaced these with regular plugs somewhere in its life. Probably because it used an odd style of plugs, not common in our region.

The controller box is from the 80's, there is no information on the internet about the manufacturer or the product itself, I don't know anyone that ever heard of it, but it dims the lights in a real analog way and it looks really cool, better than the digital controller I've temporarily replaced it with. So it would be awesome to get this working again.

Thanks in advance!

Jens

 

Welcome to AAC!

You don't need to get exact replacements. If you went with higher current or voltage ratings that will be fine.

Here is a BTA12-700.

 

Awesome that component is available from my local electronics store. Hopefully I can get this fixed now. Thank you!

 

It seems like the triac wasn't the problem after all. What other components could be bad? The fuse is okay, the triac is working fine too apparently.

 

Is it working on the other lights, or just on channel down,?

 

Is it working on the other lights, or just on channel down,?

Yes exactly, bass and middle work fine. Only the treble is not doing anything at all.

 

What a wiring mess! It's unsafe. That bundle of wires coming out through one hole in the metal back panel needs a grommet and wire anchorages, or you'll have another flash-bang soon!
It's unclear from the pics whether you actually have a triac-switched wire coming out for the treble channel. Only 2 blue wires exit the box.
Re-check all connections.

 

Then its probably the transistors that are not firing the triac, this looks like the Sound to Light that Everyday Electronics did in the 80s, using a Transformer to pick up the sound from the speakers, and bass,middle,treble controls for each light.