| 摘要 |
PURPOSE:To start and stop the DC motor smoothly by setting up a constant- voltage diode and a transistor switch outputting small signals into the base circuit of a transistor for controlling the constant currents of the motor. CONSTITUTION:When a starting command is given by an input terminal CTL, a driving transistor 8 is brought to an ON state because base currents flow through a resistor 2, a point C, the constant-voltage diode 11, a point E and a transistor 9 for starting and stopping from +Vcc, and the DC motor 1 is started. When the DC motor 1 is started, potential at the terminal of the anode of the constant-voltage diode 11 drops and the constant-voltage diode 11 is brought to a cut-off state, the control transistor 7 and the driving transistor 9 are controlled subsequently by the output of a bridge circuit formed by the DC motor 1 and resistors 2-4, and the speed of the DC motor 1 is kept constant. |
