This 80's Exar circuit has a carrier detector for frequencies up to 500 kHz. The circuit uses a company 567 which is still a common component.
This low current circuit allows the regulation of voltages in the range of 0.5 to 30 V. We find it...
We found this circuit in the January 1992 issue of Radio Electronics magazine. The circuit...
A touch of the X1 sensor causes the motor to be activated for a time that can be adjusted in P1....