This circuit with junction field effect transistors was found in documentation from the 1980s. The transistors can be MPF102 or BF245 and details of the coils are not given in the original.
When the sensor X1 is opened, the relay is energized. When waiting, the current drained is very...
Based on the LF256 operational amplifier, this circuit was found in the September 1989 issue of...
This circuit was found in a 1968’s Motorola documentation. The transistor is from that time. The...