The HK Series hour meters use a quartz crystal oscillator that generates an impulse every 36 seconds or 0.01 of an hour. The coil is triggered for 32 ms. Max power consumption is needed only after every 36s. The rest of the time the power consumption is max. 2mA. This allows battery operation and use on electronic PC Boards. On times less than 36s are not counted. A very high shock resistance guarantees accurate timing under abnormal conditions.