This circuit was obtained from an 80's Electronic Engineering. The circuit detects ice formation by triggering a warning light. The operational amplifier is of the time.
In the figure we have the way to make the three-phase control of a motor using opto-diacs. The circuit is...
This amplifier with two transistors for analog instruments was found in a Raytheon publication from the...
This circuit, with the TBA810 circuit, which is no longer common today, was found in a 1985...