This circuit uses an LED (called SSL) to regulate current in a configuration with complementary transistors. The circuit is from 1970 General Electric documentation.
Found in a 1990s US publication, this alarm circuit detects when a light beam is interrupted. Optical...
This circuit for a commercial compact digital multimeter was found in the March 1979 issue of...
The flasher we present was found in a 1982 publication, shown in the figure. What we have is a...