| 摘要 |
An overload protection system for a switching power supply includes a variable rate and variable pulse duration drive source for operating the switching transistor. Upon turn-on of the power supply, the switching transistor is driven with low repetition rate pulses having a predetermined time duration. The rate is gradually increased to a normal operating rate to minimize turn-on transients. Load sensing circuitry is used in conjunction with the variable rate drive source to cause the drive source to operate at the low rate in the event that an overload is applied to the power supply, and to turn off the drive source if the overload persists. Circuitry for providing automatic reset following an overload is employed. A feedback circuit is used to vary the duration of the drive pulses to provide automatic voltage regulation.
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