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.
ROHM Numeric Displays ROHM sells through Mouser Electronics its common anode and cathode numerical...
The frequency depends on C, which must have the indicated value ratio, and also on R, which can be...
This circuit is indicated to power TTL circuits with current drains up to 500 mA. The transistor...