Low cost integrated circuit versatile pulse and frequency counter

In this paper we describe a compact multipurpose counter whose design is based on the use of plastic integrated circuits. The circuit contains about $90 worth of semiconductor components and is very easy to wire; nevertheless, it is extremely versatile. It consists of dual 107 and 106 counters which can be used separately as two counters, or in series as a single 101 2 events counter. Frequencies up to 10 MHz can be read to the accuracy of the crystal used (typically better than 0.005%). Time intervals can be measured as either the width of a single pulse or the time interval between the positive (or negative) slopes of two pulses. The circuit can also be used as a digital integrator, since the average count of pulses in a series of numerous pulse train events can be automatically evaluated after 10, 100, 1000, or 10,000 events.