| 摘要 |
PURPOSE:To make fast starting possible and prevent waste of electric power and generation of heat by on and off a power source, which feeds a pulse phase control circuit, according to whether or not detection output to stop a pulse motor is found. CONSTITUTION:When generation of driving pulse trains from a pulse generator 1 is stopped, the level of the detection output of a detection circuit 8 becomes low. Then a light emitting diode D1 stops emitting light and a current is not passed through a phototransistor Q6. Accordingly, a transistor Q7 is turned on and a transistor Q8 is turned off. Thereby a power source E2 is cut off by a power source switching part 10, therefore, power is not supplied to a pulse phase control circuit 2. As a result, no driving pulse is applied to a power transistor circuit 4, therefore, no current is passed through the driving coils L1-L3 of a pulse motor M. Hence power is not wasted by the pulse motor M and no heat is generated. |
