We found this circuit in the 1964 RCA transistors manual. The sensor may be a common LDR and the transistor BC558. The relay has an operating voltage according to the power supply.
The circuit shown in the figure simulates an SCR with two complementary transistors, one of which...
This filter was found in documentation from the 90s. The cutoff frequency is 2900 Hz. Changes can be...
This small inverter that produces high voltage from a 6 V source was found in an American...