This circuit was found in old documentation, but it can be designed based on modern equivalent components, including the H bridge with operational ones.
This circuit of a 1964 Electronic Design uses a photodiode from the time. Modern equivalent can be used....
This VCO or Voltage Controlled Oscillator was found in a Popular Electronics from 1991 but can be...
We found this circuit for an anti-theft radar that operates at 400 MHz in a Radio Electronics from...