The circuit in the figure uses two operational amplifiers: an LM101A and an LM102. Diodes admit equivalents and resistors do not have to be accurate. The power supply must be symmetrical.
Found in documentation from the 70s, this circuit uses an operational one from that time. It goes for...
This circuit is from an old American publication. It divides a 40 to 60 MHz TTL signal by integer...
This 2004 circuit is based on the ionization effect that occurs in old incandescent lamps with...