current saving home trainer

7-24 elektor july/august 1980 1 31current saving home trainer 12 R2 100n 11 Many sport-loving Elektor readers welcomed the idea of an exercise timer or "home trainer" (Elektor November 1979 p. 20). However, having to continually keep an eye on the watch during all the various exercises seemed to them a bit of a bind. And it had yet another disadvantage — as it was constructed with TTL IC"s it required quite a lot of current. Doing exercises outside demands enough energy without having to drag a heavy and clumsy battery package around. In any case, adapting the current requirements to those imposed by cross country running proved to be quite simple. The first step to be taken towards saving current consisted in changing over to CMOS components. A single IC combining oscillator and timer (IC1), together with C2, R2, R3 and P1 which determine the frequency is sufficient to provide the clock signals required by the rest of the circuit. To save costs and space — CMOS monoflops cost...