The figure shows how to use an operational circuit as a voltage divider. The circuit is from a Radio Electronics magazine from June 1986. The reference voltage is given by a zener diode.
This circuit from a June 1957 Radio Electgronics is for oscilloscopes of the time with a maximum...
This simple receiver for listening on a crystal phone tunes the range of medium waves. The circuit...
This circuit in a receiver that allows the capture of distant stations with short waves. The...