Mass of current inrush limiters

Abstract From the Canadian patent

An arrangement to eliminate the initial current overshoot which normally occurs when a tungsten incandescent lamp is connected to a power source. The arrangement uses a negative temperature coefficient thermistor having a certain predetermined mass. It has been determined that a practical limiter to eliminate current overshoot can be made only when the mass of the limiter is within a relatively narrow range. The hot and cold resistance of the limiter must also be within prescribed ranges to give a limiter which is not only effective in eliminating the current overshoot but also, efficient in steady state operation such that the limiter dissipates less than 1% of the total power.