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A soft start circuit for a high-power module permits trickle-charging of the capacitor bank prior to power switch actuation, and avoids large current surges or inrush at power up. Positive temperature coefficient thermistor devices, or PTCs are place in shunt across the switch elements or poles of t

A soft start circuit for a high-power module permits trickle-charging of the capacitor bank prior to power switch actuation, and avoids large current surges or inrush at power up. Positive temperature coefficient thermistor devices, or PTCs are place in shunt across the switch elements or poles of the actuator or other power switch. In a power module that is powered by three-phase AC, the three power conductors are coupled through a three-pole contactor to AC inputs of a polyphase rectifier bridge, which has DC outputs coupled to the capacitor bank and to a load device, such as a high-power RF amplifier. The PTCs are connected, one per pole, in shunt across each pole of the contactor. Alternatively, metallized film capacitors can be employed in lieu of the PTCs.

대표청구항 ▼

Soft start circuit arrangement for a high power module of the type that includes power input conductors, a load device connected to said power input conductors, and a storage capacitor bank coupled across said power input conductors, comprising a power switch in series with one of said conductors, w

Soft start circuit arrangement for a high power module of the type that includes power input conductors, a load device connected to said power input conductors, and a storage capacitor bank coupled across said power input conductors, comprising a power switch in series with one of said conductors, with one side connected to said capacitor bank and load device, and another side connected to an electrical power source providing AC electrical power; a rectifier arrangement interposed between said power switch and said capacitor band and load device; and a charging capacitor coupled in shunt across said power switch for permitting said capacitor bank to charge when said power switch is open so as to avoid power surges when the power switch is actuated closed.