Editing Cellular Rotary Phone
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[[Image:GM862-Mic-circuit.jpg|400px]] | [[Image:GM862-Mic-circuit.jpg|400px]] | ||
− | Here you can see a mildly complex electret mic biasing circuit. What is this? Well, an | + | Here you can see a mildly complex electret mic biasing circuit. What is this? Well, an electret mic needs just a little bit of current to operate. Normally you can power the mic by just attaching one side to a 10k pull-up resistor. This circuit takes the 3.8V main power, and outputs a super clean 3V to biasing the mic. Perhaps getting rid of all the RF noise that the GM862 is putting onto the main power? No way! REALLY!? It works great. Why didn't we think of this before!? We use a basic 3.3V regulator and a couple caps and it works just as well. You ''can'' power the mic using the main 3.8V power, but expect some buzzing. To get rid of the buzzing, send that main voltage through a simple 3V or 3.3V regulator circuit and you'll be very happy. |
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===Board Layout=== | ===Board Layout=== | ||