This circuit from Popular Electronics powers a small speaker. The transistor can be of general use and the capacitors can be altered to change the sound generated.
This circuit shows how to use the TTL IC 7790 to divide a square TTL signal by 7. Duty cycle is...
This circuit was found in a 1994 documentation. Its signal is applied to any small integrated...
This small FM transmitter for short distances has a stereo multiplexer and can be used over an...