Hello, I have a question about a circuit that i got from here. It is supposed to be a crude long-range electret microphone listening device. I know from past knowledge that an analog signal such as sound must be reconstructed using an Amplifier that is capable of driving from both (positive) and (negative) voltages to mimic the analog voltage of sound. In the circuit which i will post below, they use a 555 timer to generate the negative voltage for the lm358.
My questions are,
1) isn't there an easier way to create a negative voltage for the Op-amp?
2) The page says that that the microphone is connected in series with a 10k resistor. Is this considered superimposing an AC waveform on a DC bias?
3) To my best of knowledge this circuit looks very bare minimum, does anyone know the legitimacy of this circuit and will it work ( even if very crude)?
P.S I tried uploading the schematic but for some reason the way the file is, it wont let me. I even tried saving the image as a PNG( but it is on the link above)
Sorry and Thanks
My questions are,
1) isn't there an easier way to create a negative voltage for the Op-amp?
2) The page says that that the microphone is connected in series with a 10k resistor. Is this considered superimposing an AC waveform on a DC bias?
3) To my best of knowledge this circuit looks very bare minimum, does anyone know the legitimacy of this circuit and will it work ( even if very crude)?
P.S I tried uploading the schematic but for some reason the way the file is, it wont let me. I even tried saving the image as a PNG( but it is on the link above)
Sorry and Thanks