Pcb Works
Sunday, May 6th, 2007How does a working contact controlled doorbell music?
I have a project kit of electronics and I welded components on the PCB. the circuit is complete, but exactly how does this work? What is the principle behind it? components: Resistors: R1 = 15K R2 = 100k capacitor C1 = 33PF Transistors: T1 = BC 547, T2 = 187 IC BEL 1 - WR 630,161 Diode: D1 = IN 4007 push to switch on speaker 8E IC Socket (16 pins) 2 Cell Holder
You do not have to share the schematic for anyone to tell you. Is this a capacitive switch? If so, look for the circuit Diagam point Contact. You should be able to see why a change in capacity will result in your FET / transistor / tube change in state ON-> off, off-> on.