This circuit is from a 1968 Texas Instruments documentation. The components are from the time and the sensor photodiode is difficult to obtain today. The circuit has a response from 10 Hz to 20 kHz.
This circuit was obtained from an Electronics Design of 1964. The circuit makes use of tunnel...
This filter was found in Radio Electronics, and its configuration can be applied to any...
This circuit was obtained from the February 1990 issue of Radio Electronics magazine. The circuit...