Found in old documentation, this circuit uses a double gate MOSFET. The operating frequencies depend on the coil, and the indicator is a microammeter.
Presence Detector (CB18741E) The original name of this project found in documentation from the 90s...
The circuit shown is the receiver for the CIR5645S, also suggested by National Semiconductor. The...
E) We found this circuit in a PE Hobbyst Handbook from the 90s. The components are common, except...