What is that black thing ?

 

Colin55-

If you read the initial post I made, it's a sound impact sensor - itty bitty microphone. I'm trying to replace that with an 1/8" plug, so I won't have to control for ambient noise. It defaults to open, and when it detects any sound of a certain volume, it closes the circuit.

 

Provide the .pdf link

 

Colin55-

Of what, exactly? My question was whether the circuit in the original article could be reversed to create a replacement for the sound impact sensor. AlbertHall said no, because it has no way of closing a circuit, and pointed me towards a thread about something similar to what I'm trying to accomplish.

I'm very much a newb to all of this. I'm a musician who has spent lots of time repairing cables, swapping out pickups, replacing faulty switches, etc., so I know my way around a soldering iron, but don't have experience designing a circuit from scratch. That's why I'm here - to try to learn this stuff.

Thanks!

 

Provide full details of:

http://elcodis.com/photos/32/57/325729/ma300dp_sml.jpg)

 

This VOX circuit activates a relay when audio is detected by the microphone. The relay is kept activated for 5 seconds after a silent period, by the 22u, to keep the relay fully activated during normal speech. The circuit takes 0.5mA when "sitting around."

SENSITIVE VOX CIRCUIT

 

My best guess is the element I'm trying to replace uses the attached schematic (taken right from the wikipedia page: https://en.wikipedia.org/wiki/Electret_microphone).

Keeping the relay activated for any period of time is something I want to avoid - I'm only trying to catch the transients of the audio signal. As soon as that peak goes away, I need to relay to deactivate, so unless I'm reading it wrong, I think most of the circuit you shared is unnecessary (and undesirable) for my purposes.

Thanks!