This amplifier with an OTA has a gain of 40 dB. The power supply must be symmetrical. Found in Radio Electronics, May 1988.
Found in an 80's Elektor, this circuit can use any equivalent optical coupler. The buzzer is of the...
This circuit with SCR and Unijunction and which can be assembled today with modern equivalents was found in a...
This circuit was developed to find intermittent defects in an electrical control. In the event of a...