| 摘要 |
The present invention relates to an electric saw (1) being powered by an external power supply (200) through a multicore cable. The multicore cable includes electrical wires (24, 25, 27) for supplying power to the motors (5, 12, 13) of the electric saw (1) and communication wires (26) for data communication between the electric saw (1) and the power supply (200). Two motors (12, 13) of the electric saw are three phase permanent magnet motors (12, 13), with an outer rotor and an inner stator. Each of the two motors (12, 13) has three Hall Effect sensors (H1, H2, H3) located around the outer rotor. In particular the invention relates to a method of controlling the saw (1) comprising the steps:
a) monitoring the electrical position and/or electrical positional changes of the second and/or third motor (12, 13); and
b) transmitting it to the external power supply (200); and
c) delivering a three phase commuted voltage to the second and/or third motor (12, 13). Further the invention relates to a communication protocol for serial communication between the saw (1) and the external power supply (200). |
