This circuit simulates a resistor controlled by digital signals. We found it in American documentation from the 90s. The basic component is a CMOS 4016 or 4066 digital switch.
This Philips commercial circuit is from the 90's documentation. The integrated circuit must be...
We found this circuit in the September 1971 issue of Radio Electronics magazine. The sensor is an...
This circuit is from a Hands-On Electronics from 1987, but it can still be easily assembled, as...