Using one unijunction transistor and two bipolar transistors, this circuit generates a signal from 25 Hz to 3 kHz. The circuit is from Electronics Now magazine, January 0, 1994.
Found in American documentation from the 1980s, this circuit uses transistors from that time. It...
This circuit of old documentation can be implemented with modern operational amplifiers. The...
This 80's circuit uses a small light bulb as an indicator, but an LED with the appropriate resistor...