This TTL circuit is from a Radio Electronics magazine from February 1973. The circuit must be powered with 5 V and the maximum frequency depends on the TTL integrated circuit.
Audio frequencies in the 300 Hz to 30 kHz range can be measured with this circuit. Transistors allow...
This dimmer or light control for incandescent light bulbs or even small heaters, is one of many...
This amplifier for a sinusoidal function generator uses a 741 integrated circuit. The circuit is...