This circuit was found in a 1967 Electronic Design. The FET is from that time. Capacitor C is determined by the frequency of the signal worked.
Indicated by Texas Instruments, this 1968 circuit measures the duration of a light pulse captured...
We found this circuit in an old English documentation. The integrated circuit is of a specific type of...
We found this circuit in a 1975 publication. The circuit can be made with more modern equivalent...