We found this circuit in a 1963 Radio Electronics. It can be used for remote control. The frequency depends on the coil and the power is supplied by a single battery.
This blinker for LEDs up to 500 mA was found in General Electric documentation from 1970....
This power supply was found in the 1996 Texas Instruments Linear Applications Manual. The circuit...
Using a CA3130 operational amplifier, this circuit drives an LED when the voltage exceeds the...