This circuit converts BCD inputs to analog voltages. The operational amplifier must be powered according to the desired output voltage range. The circuit is from documentation from the 90s.
We found this circuit in a 1977 factory documentation. The operational amplifiers can be 741 and...
This circuit with regenerative action was found in the June 1986 issue of Radio Electronics...
Equivalent FETs can be used according to the frequency of the crystal which can be up to a few...