This is a 1960s amplifier setup found in a period publication. The circuit uses a special driver transformer that inverts the phases of the signal to excite the output transistors.
This is the typical circuit of an FET amplifier stage in the common source configuration. The circuit is...
This circuit activates an LED, but it can be modified to activate a relay. The time is set in VR1,...
The circuit shown in the figure activates a small indicator lamp that will start to flash when the...