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 power supply for those who want to feed and recover 5 ¼ floppy disks was found in the...
This circuit was suggested by General Electric in 1970 documentation. It makes use of a photo-SCR...
This circuit uses the LED itself as a light sensor to self-activate it. Thus, in the light the LED...