Clapper Circuit

Thread Starter

AdamPrulhiere

Joined Nov 12, 2009
14
I am trying to build a simple clapper using this schematic. http://www.instructables.com/id/EM92NOB662EP286OAF/
Should pin 4 on the opamp go to 0V or -9V? I do not have the specific model number for the microphone I am using, it is an omnidirectional condenser microphone element from radioshack. The way this is wired, the output of the microphone is always 9V, is this right? Thanks!
 

SgtWookie

Joined Jul 17, 2007
22,221
I am trying to build a simple clapper using this schematic. http://www.instructables.com/id/EM92NOB662EP286OAF/
Should pin 4 on the opamp go to 0V or -9V?
-9v/GND/battery return.

I do not have the specific model number for the microphone I am using, it is an omnidirectional condenser microphone element from radioshack. The way this is wired, the output of the microphone is always 9V, is this right?
If you are measuring between R1 and the microphone, you may very well measure 9v.

I find the schematic very hard to read due to the colors used.
 

Thread Starter

AdamPrulhiere

Joined Nov 12, 2009
14
-9v/GND/battery return.


If you are measuring between R1 and the microphone, you may very well measure 9v.

I find the schematic very hard to read due to the colors used.

Okay thats what I thought. When I clapped near, spoke into, blew on the microphone there was no change in the voltage, it just stayed at 9V
 

Audioguru

Joined Dec 20, 2007
11,249
You need an electret microphone, not a condenser microphone.
Radio Shack knows nothing about electronic parts. Their poor quality parts might not work.

An electret mic draws about 0.5mA so its voltage should be abour 4V when powered through 10k ohms from a 9V supply.
 

Thread Starter

AdamPrulhiere

Joined Nov 12, 2009
14
You need an electret microphone, not a condenser microphone.
Radio Shack knows nothing about electronic parts. Their poor quality parts might not work.

An electret mic draws about 0.5mA so its voltage should be abour 4V when powered through 10k ohms from a 9V supply.


Thank you!
 

CDRIVE

Joined Jul 1, 2008
2,219
Beware! That circuit does not have a protection diode across the relay coil. The parts list is also riddled with typos.
 

Wendy

Joined Mar 24, 2008
22,474
There was an older thread about a year ago about the same subject. I think that gentleman may have worked the bugs out, it might be worth searching for it.
 
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