This photoelectric sensor that triggers a relay was found in an English book from 1989. The transistor is a general-purpose type, and the integrated circuit consists of an operational amplifier.
Found in a 1960s documentation, this circuit uses a transistor to drive a relay as well as a set...
The circuits shown in figure 2 are suggested by Texas Instruments (www.ti.com) make use of the...
This circuit is from the 1974 Motorola Unijunction Trigger Circuits for Gated Thyristor. The triac...