The general and simplified view of my circuit is something like that:
Using a microcontroller I want to select between two sound signal sources (S1 or S2). S1 is a signal that comes from a microphone (low voltage), S2 comes from an Arduino microcontroller (0-5v). When connected, the signals are aplified and transduced to sound waves by means of a speaker.
I've tried to use a conventional Relay but when switching it creates a spike that is amplified and can be heard. I want a silent switch.
The signals S1 and S2 are never simultaneoulsy "on", so another possibility would be something like that:
Where a device (triac) blocks (opens or closes the circuit), the triac could also be controlled by 5v from the microcontroller. A diode could be placed to block the signal and protect S2.
Looking to a device that could achieve that I found the Solid-State relays and the TRIACs. After trying to understand the differences between them and which could be the most suitable for this application I still have some doubts.
Which scheme and device would you use?
Best Answer
For this sort of application, you can use a simple SPDT analog switch such as the MAX4544:
You can get them in an 8-pin DIP from Digi-Key for $1.32.