An Electronic Tester for Logic Circuits

Abstract

The conventional method of testing logic circuits is irritating and time consuming. Described here is a tester which does not have those difficulties. A lamp is illuminated for logic state ‘1’ and is extinguished for logic state ‘0’. PNP transistors are used for negative logic and NPN transistors for positive logic. Similar circuits can be used for visual checking of the counting sequence of a binary counter.

Cheap germanium transistors have been used for economy. But, it has some limitations because of the high leakage current ICEO. It can be minimized by using silicon transistors.