This TTL time base for 60 Hz or 50 Hz can be used in instrumentation circuits or even with microcontrollers, serving as a precision shield. The circuit is based on 7400 NAND ports and two transistors.
This circuit was found in an American documentation from 1966. The transistors are from that time...
This circuit was found in documentation from Analog Devices. The circuit is based on an AD795 and...
This interesting symmetrical power supply circuit was found in the January 1981 issue of Radio...