• Welcome to our site! Electro Tech is an online community (with over 170,000 members) who enjoy talking about and building electronic circuits, projects and gadgets. To participate you need to register. Registration is free. Click here to register now.

Advice Sought for Microphone Circuit

Status
Not open for further replies.

card9inal

Member
Hey there...

I'm sorta new at this, so I'm asking for some help in figuring out what I need, and how I need to assemble the idea I have.

Basically, I'm looking for a circuit that will turn a microphone on and off. There will be one on/off switch in the box that the mic will be plugged into, so the user can easily use the switch. The biggest challenge I see is that I would like there to be another switch located in another box (stashed in another location) that can turn this mic on or off also. This way, if the user forgets to turn the mic on, the remote user can turn it on for him, and vice versa.

I would like this to be a single switch, not one for on, and one for off on the remote box. These switches, one on the main box, one on the remote box would be momentary pushbuttons...

What type of circuit can alternate states like this from two locations?

Thanks!
 

Boncuk

New Member
Hi,

you might use this circuit.

The MAX16054 toggles its outputs with every pushbotton operation. It has a built in switch debouncer circuit for safe operation.

Connect any number of pushbuttons parallel with PB1.

With output Q (pin5) you activate the ground supply for your microphone. Output /Q (pin4) is low while pin5 is high. Toggling Q low /Q goes high, indicating "Mic Off". To reverse indication for "Mic On" connect the cathode of the LED to R3 and the anode to VCC.

If your microphone has the same supply voltage connect VCC to Mic+, otherwise connect the mic supply voltage at this point. Don't forget to connect both ground wires of different supply voltages.

Boncuk
 

Attachments

card9inal

Member
To make sure I understand at least part of this correctly, if I add another pushbutton switch in the other box, I can connect it to any ground? As long as it's in parallel to the original switch, correct?

Could I then use the output, to control a relay which would turn the mic on and off? I.e. short it with a resistor?

I like the LED idea. I just wonder if this could be placed in the remote box as well...

Thanks for your help!! It's greatly appreciated!!
 

Boncuk

New Member
To make sure I understand at least part of this correctly, if I add another pushbutton switch in the other box, I can connect it to any ground? As long as it's in parallel to the original switch, correct?
Connecting the pushbutton parallel to the original one it's not "any ground", but circuit ground.

Could I then use the output, to control a relay which would turn the mic on and off? I.e. short it with a resistor?
The circuit interrupts ground to the microphone, which is the same as cutting the power off. (I assume you are using an Electret mic.)

like the LED idea. I just wonder if this could be placed in the remote box as well...
You might place the LED anywhere you want. Just connect it to the circuit according to the schematic.

Thanks for your help!! It's greatly appreciated!!
Welcome
 
Last edited:

card9inal

Member
I will not be using an electret microphone. This circuit will be used as part of a larger system for professional sports broadcasts, so depending on the game or talent, it will either be used with a dynamic headset mic, or a condenser mic.

I don't know if shorting this mic to ground will mute the audio. In doing some research, I found a schematic for the Pro-Co Cough Drop, and it shows that they have pins 2 (Mic +) and 3 (Mic -) were tied together with a resistor and capacitor. I used one of these boxes a long time ago and it provided click free muting and worked really well.

Is there another way to mute the audio, or will a relay be the best option?

Thanks again!!
 

Boncuk

New Member
You might use the same circuit with another IC being controlled by it.

Shorting the mic you'll disabling it click free and free of noise. I'll change the design accordingly.

Boncuk
 

Boncuk

New Member
Revised circuit design

The circuit now uses an analog SPST circuit to short the mic to ground when switching it off.

The input circuit was not changed.

The PCB is 1X1 inch.

Boncuk
 

Attachments

card9inal

Member
Where can you find those Maxim chips in small quantities?

Thanks for your help.

I think I've got it somewhat figured out, but you definitely put me on the right track!

What application do you use to design your PCB?
 

Boncuk

New Member
You can find the MAX16054 at Digikey.

Rechecking the schematic design I discoverd that the mic-off indicator was connected the wrong way.

I've revised the circuit and added another LED for mic-on indication.

Boncuk
 

Attachments

Last edited:

card9inal

Member
Sorry for the delay in response, I've been traveling all over!

I've found the chips online at Maxim. If you order them from Digikey, you have to purchase 1000 of them! Maxim sells them individually. Are there any other chips that do the same thing in a larger, non surface mount chip?

Here's another question...

Is there a way to make a single button be a "push to talk" and "push on/push off"? Basically, if you pressed and held the button, it's active until you release it, but if you quickly press and release, it stays in the on position, until you press and release again.

Thanks again!!
 
Status
Not open for further replies.

Latest threads

EE World Online Articles

Loading
Top