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.
This circuit with signal acceptance filter was found in the June 1993 Electronics Now magazine. Other...
We found this 555 integrated-circuit tester in an old Electronics Hobbyst from 1977. The circuit is...
Found in a1969’s neon lamp documentation, this circuit uses a high voltage transistor. The output...