Soft Start Inrush Current Limiter- PCB design

[Muzzer]

One issue with a thermistor is the fairly long time constant for it to cool down again and until it does so, the resistance may be too low to prevent tripping the breaker. For an application like a welder, the transformer needs to be restarted frequently (controlled by the torch switch), so a fixed resistor works well. For my 300A single phase TIG welder with up to ~70A input current, the timer / resistor solution seemed the best solution.

For my CNC machines, the soft start event only happens when the machines power up. However, the operating load current varies significantly from idle to full chat. May not be an issue but I'd rather not have a large, continuously hot body in the cabinet.