A Low-Power Electromechanical Digital Readout

The construction of two types of seven-segment electromechanical digital readouts is described and analyzed. One type makes use of seven revolving cylinders; the other type is based on seven translating bars. The cylinders and bars contain permanent magnets which are activated by small electromagnets. The lowest power design requires only 0.9 mJ per segment, which can easily be supplied by present-day integrated circuits.