This 1980s documentation circuit uses a 741 in a different high-speed comparator configuration. The feed must be symmetrical. The diode is general-purpose.
This circuit was found in an American documentation from the 60's. The transistors are from the...
This oscillator is indicated for the adjustment of FI of FM radios, having its frequency...
This configuration triggers an external circuit or simply an LED for time given by R1 and C1 (T =...