With the indicated components, this circuit oscillates at 1232 Hz. Consider the tolerance of the components. The circuit is from a 1974 Ferranti transistor manual.
This traditional flasher configuration with two transistors drives 5 LEDs with a supply that must...
To operate with high input voltages using a 3-terminal voltage regulator such as the LM340-15, we...
This is the circuit of the commercial Japanese megaphone of the 60s model DM-218. The circuit uses...