| 摘要 |
The ignition switch start contacts (2) energise the starter's solenoid coil (1b,1c) via a microprocessor (3)-controlled switching transistor (T). After an unsuccessful start, the latter conducts only if zero voltage is detected (4) at the motor terminal. The motor current is derived from the battery (B) via the contacts (1a) of a solenoid switch (1) whose coils (1b,1c) are energized from the battery when the driver closes the ignition switch start contacts (2). An e.g. MOS transistor (T), interposed in this circuit, is controlled by a microprocessor (3), on the same circuit card, according to a voltage input signal (e) from the motor side of the transistor. Only if this voltage (Us) is zero, as is normal just before unsuccessful start attempt, the motor, disconnected from the battery, generates a voltage due to its remnant armature field. Opt., in permanent magnet machines, the field continues. Current circulates through the solenoid coils and earth, producing a signal (e) proportional to the motor voltage (Ui). The microprocessor through the transistor effectively disables the start switch (2) till the motor stops. With wound armature motors signal amplification may be necessary. |
