Seiko Elnix 0703 Electronic Balance movement
This is an unusual electronic balance movement from the earty 1970's. In contrast to conventional mechanical movements in which the role of the balance is to regulate the power from a mainspring via the escapement, an electronic balance watch works in a reverse sense. The balance itself is driven directly by an inductive interaction with an electrical coil sitting at its centre and its function is then to transfer power to the gear train via the pallet and escapement. This is something of a forgotten technology but provided a short-lived technological bridge between the settled mechanical status quo that existed prior to the 1970's and the quartz revolution that was to kick in from the early '70's.