Originally designed for WWV (Standard Time Station) signals, it lets 1 kHz tones pass by rejecting the 440 and 600 Hz tones emitted by the station. The circuit is from a 1964 Electronic Design.
The integrated circuit used in this 80's application is not common today. However, modern...
This circuit makes use of the Linear Technology LT6100. We find it in a 2005 company manual. The...
This General Electric circuit produces pulses of light only when light stops shining on the...