This circuit using only transistors was obtained from Ferranti's 1969 documentation. It can be made from modern transistors. The circuit is 4 bits.
We found this circuit with a Q factor of 25 in the Linear Applications Handbook by National...
This circuit was found in a Japanese publication from 1971. The circuit uses components from the...
When this circuit is activated the LED flashes for a moment indicating that the function has been...