Found in a 90s Popular Electronics, it serves both TTL and CMOS logic. The injector can provide 10 kHz or 100 Hz signals. The circuit drives a transducer and two LEDs.
This is actually an automatic dimmer we find in an American 1980s documentation. The triac must be...
This very high voltage (VHT)generator was found in a 1995 documentation. The transistors must be...
This circuit was found in an old Popular Electronics. It causes an LED to pulse and, at the same...