This circuit was found in a Popular Electronics of the 1990s. The sensor is a rotating mechanical system with a propeller-driven magnet to count pulses with a reedswitch.
We found this shield circuit in the SGS Integrated Circuits Manual of 1982. The circuit is...
This circuit with transistors and a crystal microphone appeared in Radio Electronics magazine in...
This circuit amplifies the signals in the UHF band starting at 470 MHz, reaching just over 900...