Electromechanical switching technology

the same as with other display devices from the past: you turn them into a clock, just like the Nixie-tube clock elsewhere in this issue. Such components from the old parts box are eminently suitable for all kinds of designer timepieces, the combination of old and new technology has a certain appeal. The picture of the clock that we are describing here immediately reveals the origin of the counters, that is, an old electromechanical pinball machine. The clock is built into the so-called backglass. The five large relays underneath the counters are the control logic for the number wheels, the PCB at bottom left provides the clock ticks and is with its CMOS-technology an anachronism. But with EM-technology a pulse generator is indispensable. In the case of a clock you need a pulse every minute (start of a new event) followed by a few quick ones after that to get all the number wheels in the correct position (processing the event). In an EM-pinball machine the ‘start’ is caused by a target that has been hit by the ball, which then starts a score-motor which in turn generates the required pulses and – depending on the state of various relays – ensures the correct processing of the points scored and then finally stops again.