The purpose of this circuit is to convert a short-lived pulse into a negative rectangular pulse. The circuit uses a unijunction that can be replaced by an equivalent such as 2N2646.
This dual time constant circuit was found in the October 1987 issue of Radio Electronics magazine. The...
Using the LM3909 this circuit was found in the January 1992 issue of Radio Electronics magazine....
This circuit uses only one NC75Z04 port from ON Semiconductor, but it can be implemented with...