This circuit uses an LDR as a sensor to trigger an LED indicator at a preset lighting level. The power supply does not have to be symmetrical.
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 =...