Externet
Well-Known Member
An existent LM4863 power amplifier IC needs to be fed by at least 100mV rms to yield the desired level at the speaker, as probed in its 'normal' operation.
A piezoelectric microphone needs to be applied to the input instead, and thought a 2N7000 N-channel-enhancement mosfet could be of use as single stage preamplifier (as I have 2000+ pieces in need of use)
But no, cannot get a decent level. Would it be possible to use a 2N7000 ?
Battery is 4.0V.
Gate is between 1MΩ to +; and 1MΩ to gnd.
Drain has 1KΩ to + and source 1KΩ to +
Output is after 1μF at the drain.
Any suggestions ? Raise value to both MΩ resistors ? Or is it a lost case ?
A piezoelectric microphone needs to be applied to the input instead, and thought a 2N7000 N-channel-enhancement mosfet could be of use as single stage preamplifier (as I have 2000+ pieces in need of use)
But no, cannot get a decent level. Would it be possible to use a 2N7000 ?
Battery is 4.0V.
Gate is between 1MΩ to +; and 1MΩ to gnd.
Drain has 1KΩ to + and source 1KΩ to +
Output is after 1μF at the drain.
Any suggestions ? Raise value to both MΩ resistors ? Or is it a lost case ?