Switec motor measurements

The Switec motor has been developed as indicators drives for dashboard instrumentation and other indicator equipment. Two 290 Ohm coils are connected with 3 wires and receive a 6-step phase per turn, like for the ETA motors. The Switec M-S (7.7 g) has a single 1 mm output axis with a 1:180 reduction. The Switec ACC (8.4 g) has two concentric axis: the minute shaft (0.8mm in diameter) with a 1:60 reduction and the hour shaft (1.4mm) with a 1:720 reduction. The Switec ACC has a magnetic retention force the M-S does not have: it is about 2 g on the minute axis, and more than 50g on the hour axis.

The Switec coils can be directly driven by the PIC outputs, but it is suggested if possible (what we didn't do in our case) to connect two PIC output pins to the point having the two coils connected together.