Inrush Current Limiters

Ametherm's inrush current limiters are designed to protect your
components from damaging levels of inrush current at startup.

MegaSurge Rated to 50 Amperes and 900 Joules of input energy. For Motor Drives, Audio Equipment, and Power Supplies	bigAMP Rated up to 36 amperes and 260 joules of input energy. For UPSs, Motor Controls, and Power Supplies with 750 watts or higher output.
miniAMP Specially designed for value. Available in 3, 5, and 8mm diameters and weigh as little as 0.225 grams	Standard Large variety of the sizes and electrical specifications of the most common inrush current limiters.

Inrush Current Limiters Power Electronics article discusses applications and uses of inrush current limiting thermistors	Inrush Current FAQ Frequently Asked Questions about inrush current limiting thermistors
Inrush Current in Transformers A sample application of inrush current limiters in transformers	Inrush Current Causes and Prevention A summary of inrush current causes and prevention
Ametherm Imax Derating Curve Ametherm Derating Curve	Ametherm Zero Power Resistance Curve Ametherm Zero Power Resistance Curve

Inrush Energy (J)

How To select an Inrush Current Limiter

Use the maximum allowable surge current and Ohm's Law to determine the least allowable resistance at turn on for your application.
Using the formula J = .5CV^2, determine how much input energy the thermistor will absorb when the device is turned on.
Determine the maximum steady state current that will flow through the Inrush Current Limiter.
Select the Inrush Current Limiter that will work for your application.

Power Thermistor Selection Calculator

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Inrush Current Limiters - Ametherm