This circuit converts a high voltage into a frequency using an optical coupler. The transistor can be 2N2646 and the coupler admits equivalent. The circuit is from a 1974 publication.
This circuit was found in a 1973 publication. With the components indicated, the range can be from...
We found this circuit in the Linear Applications Hanbook of the National Semiconductor in 1994. The...
The integrated circuit used in this project is unusual. We found this configuration in Motorola's Linear...