Reverse Lightning - 120v relay

[TommaHawk]

Check me here...

My 3-channel color organ (lightning machine) runs on 120vac. To hack in a reverse-flicker (the room lamp/other lights flicker off when the lightning lights fire on) I picked up a standard 120vac DPDT relay and socket. I'll splice the coil contacts to one of the lightning channels, so I assume:

1.) I must drive that channel's lightning bulb with the NO contacts (pins 3&4) piece of cake
2.) The room lamp is driven off the "other" 120vac power-in contacts (pins 5&6) and the NC contacts (pins 1&2) another piece of cake

But...

3.) Is it alright to pigtail the 120vac in to both the circuit board and pins 5&6 on the relay, or must I have a totally separate 120vac line into pins 5&6 (assuming my room lamp is 120vac)?

I think I can pigtail without a problem but...
Attachment 402

[Otaku]

TommaHawk,
Here's the pinout for your relay:
1 + 2 are the NC pins
3 + 4 are the NO pins
5 + 6 are the Commons
A + B are the coil pins

To set up a reverse flicker for the house light, wire the Coil pins (A+B) in series with one of the lightning bulbs (pick a channel). The coil shouldn't pull much in the way of wattage so you won't notice a drop in brightness. Now the relay will energize whenever that channel is active. Wire the power to the house light in series with pins 1 and 5 OR 2 and 6. The NC contacts will open when the channel goes active, switching off the power to the house light. Let me know if you have any questions. Remember that you're working with 110VAC and be sure to insulate the connections.

[TommaHawk]

What was I thinking? Little embarrassed - must be pretty tired to list out my pins as I did above. 1&5... gotcha, that makes more sense (remembering that this is a DPDT). I'll try this ASAP, and if it works, I'll post a diagram of the circuit. If not, well, I'll post a picture of the charred remains.

I'll pigtail the power to both components rather than bringing in a separate 120vac line - the power draw of the lamp and circuit bulbs are pretty minimal, especially since one will be active while the other is not.

[Otaku]

The house light will have it's own power, right? The only things the color organ channel should be powering are the relay and the lightning bulb.

[TommaHawk]

So, the lamp will have its own power, driven through pins 1&5? I don't have to power the lamp separately (though driven through pins 1&5)? Shouldn't the color organ power the lamp through the NC contacts the whole time?

Here's my thinking - that particular channel only receives power from the circuit when the conditions are right (like sound in the high end of the spectrum). I'll need to power the room light separately with it's own 120vac plugged into pins 1&5 (NC), so when that channel is activated the relay will cut to the NO pins thus cutting power to the lamp?

[Otaku]

You got it. Only one of the two wires from the lamp will be connected in series to pins 1 and 5. The same goes for the color organ channel wires. For the relay: one of the two wires from the color organ will go to pin A, a wire goes from pin B to the lightning bulb fixture/socket, the return goes from the other connection of the socket back to the color organ. For the lamp: one wire from the plug goes to pin 1, a wire goes from pin 5 to the lamp. When you plug everything in, the lamp will be on, and will go off when the channel is active.

[TommaHawk]

Ah ha! Yes, I have it. Thanks your your sanity check.

But again, if I wanted to have a single power cord powering the lot, couldn't I pigtail that one wire from the power cord to pin 1 and the organ? What I'm picturing is a relay switching power on and off to another socket (that the lamp is plugged into), sort of an all-in-one solution. Plug your three lightning bulbs into the three channels, and a lamp into the "fourth" socket (sorry - maybe I should have mentioned this earlier). That would work, yes?

[Otaku]

Yes, that should work. Just be sure that the color organ won't be turning off it's own power.

[gmacted]

Sorry to chime in so late, but I would not use a mechanical relay for this application. Mechanical relays aren't really designed to be switched on and off rapidly. They have a "mechanical life" and will cease to work after so many operations. It may work for a while (the switching speed may be too great however for the relay), but it will fail over time.

[Otaku]

gmacted is right about that. If you can use an SSR (solid state relay) you'll definitely get longer lie. They're pricey, though, the one you'd need would go for ~$25-30.