This circuit was found in a 1966 General Electric book. The triac and the day are from that time and can be replaced by modern equivalents depending on the load.
This circuit is from a 1995 publication; The current is obtained by dividing 1.25 by R1. The...
We found this circuit in an old American publication. It is possible to test common FETs using a...
This circuit was obtained in a 90s documentation from Analog Devices. The sensitivity is in the...