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FAQ01857 of Power Controllers FAQ

FAQ No. FAQ01857

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What is a soft start?


Soft start is a function that enables smoother starting by suppressing the inrush current when the load power supply is turned ON. Soft starts are particularly useful for loads with large inrush currents, such as halogen lamps.

The G3PX Power Controller has soft start, soft up, and soft down functions that adjust the soft start time and the up/down times using hardware adjustments. This prevents sudden changes to outputs, which shorten heat life.

A halogen lamp has three to five times more inrush current if it does not have a soft start function. (The inrush current time is short.)
Such a large inrush current has a huge impact on the G3PX itself and the system.

If the halogen lamp is used with a soft-start function it gradually turns ON, starting with the smallest phase angle, as shown in Fig. 2.
This is how the inrush current is suppressed.

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