Suggested by General Electric, this circuit with triac is able to reverse the rotation of a motor through a DC control signal. The circuit applies to AC servos.
Approaching the hand or an object to the sensor of this circuit, the relay closes its contacts. The...
For those who want to recover an old multimeter of this type, the circuit presented is worth...
The circuit shown is only for analog telephone lines. I found it in Popular Electronics (1991). It...