multitester

multitester elektor may 1983 E. Osterwick Any type of test equipment is useful but they can take up a fair amount of space, especially if the workshop is quite small. The design here counters this problem by combining a number of simple test circuits into a single package. Basically it contains a logic probe, a clock pulse detector and a simple voltage level detector. It is made even simpler by the absence of visual displays of any sort. The output indication is made audible by the use of a small speaker. multester • A logic tester for TTL levels • A voltage supply checker • A clock pulse detector • Acoustical indication Figure 1. The circuit of the Multitester contains very few components besides the three ICs. The basis of the circuit con- sists of two oscillators, N2 and N3, and the counter IC3. The Multitester is a very simple circuit with many useful points — not the least of which is its extremely low cost. Basically the circuit consists of little more than three I...