Current limiter guards against current in-rush problems

A new current limiter module, designed to reduce the current surge when loads such as transformers (especially toroidal types), switch-mode power supplies or small motors are first switched on, has just been introduced by REO UK Ltd. Key features are said to be compactness and high efficiency.

The ED1/16 module eliminates problems such as blowing of fuses and nuisance tripping of breakers due to momentary, excessive current draw by the load, during start-up. The ED1/16 is suitable for applications where initial current in-rush might be up to 7-10 times nominal across frequencies ranging from 45 to 65Hz.

A semiconductor is used to reduce the supply voltage level for the first few mains cycles (approximately 500ms in duration) and then afterwards the semiconductor is bypassed allowing the voltage to rise to its nominal mains level. The unit has a nominal current rating of 16A.

Installation is very simple; the module clips onto a standard DIN rail and has screw terminals for a series connection with the load. Dimensions are: approximately 10cm x 8cm footprint x 8cm high.

The unit was first developed for use with medical transformers that are also produced by REO