| 摘要 |
An apparatus for controlling the load dump voltage of a permanent magnet (PM) alternator having a silicon controlled rectifier (SCR) bridge. The apparatus includes a voltage divider, a peak detector, and a comparator. The voltage divider attenuates the bridge output voltage, which is further fed through a peak detector to hold the peak value for improved stability. The comparator changes states when the bridge output exceeds a predetermined voltage level (e.g., 55 volts) that is less than the load dump threshold limit (e.g., 60 volts), but greater than the normal operating voltage (e.g., 42 volts). The comparator output change-in-state deactivates a gate pulse generator, thereby suppressing further operation of the SCR bridge. Voltage transients that may otherwise occur at the bridge output for the remainder portion of a half cycle from the PM alternator are clamped using a varistor or zener diode.
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