Archive for April, 2008
Electronic cricket insect sound circuit schematic
Many people like the cricket sound specially if they live in a big town. This electronic cricket sound works in pulses, so the battery life is prolonged, the current consumption is just 2mA.
The electronic cricket schematic is very simple, it is build with CD4049 or CD4009 wich is CMOS Hex Buffers/Converter.
Dynamic microphone amplifier - low noise
This dynamic microphone amplifier circuit has a total gain of 200 times. If we use 200Ω microphones R4 must be 220Ω and C1 is 4.7uF. If you want the to get the lowest noise signal from this dynamic mic amplifier use metalic resistors for R3 .. R6 and for C1 use more MKM capacitor in [...]
Electret microphone amplifier circuit
This article describes an compact electret microphone amplifier but you can connect dynamic microphones with low resistance. Electret microphones can be inserted in the same box with the amplifier, it only need 5 to 10V or 9V battery with a current consumption of just 1.5mA.
Here you got the electret amplifier schematic:
