Powerbox PB315 high-efficiency converter

Powerbox has designed a high-efficiency converter to supply locomotive headlights. The dual output PB315 replaces dropping resistors currently used to dim incandescent headlights on locomotives.

The resistors waste battery energy as heat, which in turn adds to the air-conditioning load, which requires more energy for cooling.

With high switchmode efficiency of around 90%, the device provides significant energy saving compared with resistors. The converter is ruggedised against shock and vibration and much less prone to mechanical failure as compared with resistors. In addition, the unit provides a much more stable output voltage and a softer start-up, minimising electrical stresses to the filaments and adding to the lamp life.

The device is designed to supply 2 x par 56 lamps ie, 2 x 68 V, 4.6 A high beam and 2 x 32 V, 3.3 A low beam. These outputs can be modified to suit other lamps. High/low beam is controlled from a toggle switch inside the cabin. The converter provides a headlight fail alarm via a set of volt-free contacts. Units are available with screw, fasten or cage clamp terminals.