| 摘要 |
PURPOSE:To prevent a power transistor from damaging at a power source turning time by interrupting the transistor provided that a power source for a controller is not sufficiently risen. CONSTITUTION:5V- and 24V-power sources are gradually raised when a power source is turned ON. When the 24V-power source is first risen, the 5V-power source is not yet risen. Accordingly a transistor 30e is in OFF state, and transistors 30i, 30j are turned ON. Thus, power transistors 11c, 11d are turned OFF, and might not be damaged. When the 5V-power source is raised to the normal state, the transistor 30e is turned ON, and transistors 30i, 30j are turned OFF. Thus, the power transistors 11c, 11d are controlled by a mode setter 12 in response to the motor drive signal. |
