We found this circuit in the June 1991 issue of Radio Electronics magazine. The integrated circuit is still available. The table gives the component values.
March 2017 - Microchip's new 8-bit PIC16F15354 microcontrollers can now be obtained from Mouser...
This circuit, suggested by Signetics can be used as a shield. Modern operational can be employed...
This circuit was found in a Popular Electronics from the 90s. The circuit uses general purpose...