This is the receiver for the previous circuit, also found in 90s Radio Electronics. The circuit operates at 2.25 MHz, detecting variations in signal frequency due to the Doppler effect.
This circuit is from Motorola's 1990 Linear Databook. We can implement it with other operational...
August 2017 - Mouser Electronics already has to supply the new Darlington MAAM-011206 Broadband...
This proximity sensor circuit is from an 80's documentation. The used integrated circuits are...