Microphone mic switch controlled by proximity sensor

Thread Starter


Joined Nov 26, 2019
Hello, all.

I'm looking out to design a microphone mute switch which is controlled by a small IR proximity sensor and powered by a consoles phantom power.

There are some commercial hardware solutions for this purpose which go way over the budget I have available.

Since I'm a bit rusty on the electronics classes I had in the 90's and being out of the electronics development for so long, I'd appreciate any help on the circuit design and implementation of such piece.

The specs I require for the hardware itself are as follow:

- Powered by 48V phantom power
- Ability to mute a balanced XLR signal
- Controlled by a proximity sensor

The main purpose is to be able to have a talkback microphone for musicians to use on stage to communicate with the monitors engineer without a push to talk or physical switch which is difficult to operate in the case of drummers or keyboard players.

The muting circuit should be implemented in a way to avoid any pop on the signal, when turning on or off, since it's being powered by phantom.

One of the main concerns on the circuit implementation has to do with the fact that phantom power isn't able to provide much current to power the circuit and the sensors I believe are able to achieve the desired result are powered by 5V.

As some users from the Gearslutz forums suggested, I was considering the use of an optoisolator to control the microphone signal such as the H11F1M and for the IR proximity sensor we were considering a cheap circuit with a LM393 comparator circuit as the one from this link .

Any help on the design would be extremelly appreciated.

Thank you in advance.