ECS Slave Dials - One-Minute Advance
The Memory Master clocks provide a pulse every 60 seconds for the advancing of the slave dials. The polarity of each pulse is the opposite of the previous pulse. In this way multiple pulses caused by badly maintained contacts within the master clock cannot upset the synchronisation of the slave dials.
Slave dials for the Memory Master clocks use a polarised rotary stepping motor to advance the hands, and this design is almost silent in operation.