Swiss made impulse movement as used by the Swiss Railways (Bundesbahn).<br />This one was fitted in a pilot dial<br />Motor 48 Volts 50 Hz<br />Impulse ± 24 Volts every minute, bipolair drive.<br /><br />The gearwheel in the middle drives the second hand. It has a clutch which allows it to slip when the pin latches with the pawl.<br />When the minute impulse activates the coil to advance the minute hand, the pawl moves to the left and the second hand is released again.
