Through the TTL output this circuit can be used as a shield. The sensor is a platinum probe, and the operational amplifier can be replaced by a modern equivalent, preferably of low voltage.
Random pulses are produced by this multiple oscillator using unijuncion Transistors. The...
This watch was found in 2001 documentation. The watch is powered by 4 batteries. To save energy, the...
This circuit with the PA7601 was found in a 1967 Philco-Ford documentation. The circuit has a pass...