![]() No electrolytic capacitors were used at all in the design. The only reason I used 100 ♟ was that I had a bunch of these ceramic capacitors on hand, and they were 1210-size surface mount parts, so fit easily on the breadboard. R2 provides the bias for the microphone input, and when there is loud singing into the mike, the voltage across the mike varies by perhaps 50 mV peak-to-peak.Ĭ2 blocks the DC component of the signal, passing the AC portion into the amplifier. Only the left channel of the circuit will be discussed, since the right channel is analogous. So I threw together the following circuit: Click on the picture to see it full size. The computer’s microphone input is designed to put a little bit of bias current through that resistor, and amplify the AC component of the resulting voltage. The microphone produces no voltage of its own. They’re basically resistors of maybe 10k ohms, that vary with sound. Funny, it worked fine connected to the MIC IN jack of my computer… On the internet, I quickly discovered how most inexpensive computer microphones work. ![]() I connected the pink stereo mini-plug to the LINE IN of my recording device, and got silence, no matter how loudly I screamed into the mike. Just the thing for a secret project I’m working on! I’m smiling because I scored brand new headsets at 2/$5. ![]() I recently got a couple computer headsets at a local flea market.
0 Comments
Leave a Reply. |