Solid-state relays appeared on the market relatively recently and have already confidently conquered the radio electronics market. It’s understandable, I’ll give you the main advantages.
- - Performance.
- - Galvanic voltage isolation.
- - Quiet compared to a conventional relay.
- - Zero crossing detector.
There are many more advantages, I have cited only a few.
A solid-state relay, in essence, apart from the name, has nothing in common with a mechanical relay, which everyone usually imagines when hearing this name for the first time. This is a regular triac switch, with control and decoupling circuits.
This miracle is quite inexpensive and can be easily bought on our favorite Aliexpress.com
Link to solid state relay.
There are many different versions of relays on the radio market: small and large, powerful and low-power. I took this:
Firstly, it has screw terminals for connection. Secondly, it can switch a load with a voltage of 24-380 V and a current of up to 60 A. Of course, I took it overkill for other purposes.To control a garland, it is enough to take from 2 A. Thirdly, the control voltage is from 3 to 32 volts, pulsed. Just what we need, since we will control the relay directly with the sound supplied from the output of the low-frequency amplifier.
Light and music circuit
A solid-state relay is connected to the open circuit of a lamp or garland. And the sound from the speaker is supplied to the input of the solid-state relay. The scheme couldn't be simpler. The main thing is not to confuse the conclusions. Now, as soon as the music starts playing in the speaker, the garland will immediately start blinking in time with the music.
We take the output from the amplifier from any channel, left or right. You can connect between the outputs so that the garland flashes with a stereo effect. If there is a subwoofer output, you can connect it to it. Or you can take two garlands and two relays and connect to different channels. There are a lot of options, choose any one you like.
I added a park of toggle switches to the circuit for switching. The first toggle switch in the diagram is so that you can simply turn on the garland in normal mode. And the second is to turn off the influence of music on her.
Thanks to galvanic isolation, high mains voltage is reliably isolated and will not pass through the speaker and amplifier.
I took a plastic container and placed sockets there to connect the load. I made holes for the toggle switches and connected the entire system.
The load was an LED garland on a Christmas tree. I immediately connected to the speaker that stood near the Christmas tree.
The result turned out very cool, watch the video of the work:
