| 摘要 |
PURPOSE:To attain low-speed stability and high-speed rotation, by providing switching elements between the winding terminals of a pulse motor to selectively couple a control resistor and a diode in parallel with each other depending on the revolution speed of the motor. CONSTITUTION:In slow rotation, a turn-on signal is applied to the input terminal 5 of a control transistor Tr5. Windings L1-L4 are sequentially energized by control signals applied to the input terminals 1-4 of switchng transistors Tr1-Tr4. Counter electromotive forces, which are caused across the windings when the switching transistors are turned off, are consumed through diodes D1-D4 and the control transistor Tr5 to cause braking action. In rapid rotation, the control transistor Tr5 is kept off and the counter electromotive forces are consumed through a control resistor Tr1 to reduce the effect of braking. |
