This circuit is from a 1968s Motorola documentation. The load can range from 10 to 100ohm and the transistor supports a modern equivalent such as 2N2222 or BD135.
This circuit is from a Popular Electronics from the 90s. The circuit has a tone frequency...
This solar powered circuit was found in a 1991 documentation. The transistor is a general purpose...
This circuit is based on a common cathode 7-segment display. The circuit is based on CMOS...