Electronic timer esp. for parking meters - monitors accumulation of clock and control button pulses and delivers data to memories

摘要

The electronic timer is esp. for parking meters. The timer can provide measurement of different periods, normally multiples of thirty minutes and an audible signal at the end of such a period. The timer has a clock pulse generator and an associated counter delivering an output at the end of each period. Two memories are employed, one storing the clock signals, the other storing those initiated by a control button. A comparator monitors the accumulation of such pulses and delivers an output when both memory contents are equal.