Hey all. I am just beginning with electronics and I bought a kit to make this sound generator. I soldered everything together and it works which is great, but I don't understand how it works which is frustrating and lame. I know what all the symbols stand for on the schematic, but I don't know how they are working together to make the thing work and I don't understand how the power is flowing through the circuit..... any help would be very much appreciated.

The parts included are:

1x .022 microfarad Disc Capacitor
1x 4001 CMOS IC
1x MPSA 13 Darlington Transistor
1x 24K ohm Resistor
1x 150 ohm Resistor
1x 510 ohm Resistor
1x Speaker
1x CDS Cell
and then a 9v batter connector, wires for the speaker, and a 14-pin IC socket.

I think probably you guys with experience already know how it would be assembled, but if you want the schematic I can probably scan it or something....

I really want to understand circuits and maybe someday make a circuit of my own without instructions...please help me out eh.

Thanks!

 

I think this is similar schematic to your circuit. I'm pretty sure that U1A and the CDS cell are setting a DC voltage level for the Cap(C1). The other two gates are arranged as an oscillator. The output of each one feeds back into the input of the other. The DC voltage level on C1 sets a threshold at which the oscillator will toggle its output. Meaning it determines the frequency of the two gates oscillations. The change of resistance created by CDS varies the voltage and therefor makes the oscillations change with varying light levels.

Your kit uses different parts but should be arranged in very similar manner. The transistor is probably acting as an amplifier for the speaker. Your kit has a different value cap and some different value resistors, but react the same as the one above.