As is fairly well known, the saloon lighting in traditional loco hauled coaches is often self contained.
A battery under each coach is charged by a dynamo, this being belt driven from an axle. This system has the merits of operational simplicity since any coach so equipped may be hauled by any loco.
The equipment is however rather complex, it needs to produce DC of the same polarity despite changes of direction, the battery charging voltage needs to be regulated, and the voltage on the lamps also needs regulating.
With the low speeds and frequent stops on a heritage railway the batteries tend to become discharged and the lamps very dim. In an attempt to limit battery discharge, many heritage railways remove half the lamps and/or use lamps of lower power than was originally intended.
The lamps are usually 24/25 volt, often 15 or 25 watt. These lamps give a poor light since they are designed for least cost and long life, not efficiency.
I would therefore suggest that heritage railways give consideration to replacing these lamps with LEDs.
LED lamps are available that use 2 or 3 watts and give a similar light to 15 or 25 watt incandescent lamps.
The light output is constant over a range of 10 volts to 30 volts, no dimming or flickering with changes in speed.
The much reduced load will greatly increase the battery life, and may permit of a few more years service from batteries otherwise considered life expired.
Anyone here who volunteers as an electrician on a preserved line ?
Although this is a RAILWAY forum, these new LED lamps are also worth considering for vintage buses, yachts, caravans etc.
I have no connection with any vendor of these lamps.
A battery under each coach is charged by a dynamo, this being belt driven from an axle. This system has the merits of operational simplicity since any coach so equipped may be hauled by any loco.
The equipment is however rather complex, it needs to produce DC of the same polarity despite changes of direction, the battery charging voltage needs to be regulated, and the voltage on the lamps also needs regulating.
With the low speeds and frequent stops on a heritage railway the batteries tend to become discharged and the lamps very dim. In an attempt to limit battery discharge, many heritage railways remove half the lamps and/or use lamps of lower power than was originally intended.
The lamps are usually 24/25 volt, often 15 or 25 watt. These lamps give a poor light since they are designed for least cost and long life, not efficiency.
I would therefore suggest that heritage railways give consideration to replacing these lamps with LEDs.
LED lamps are available that use 2 or 3 watts and give a similar light to 15 or 25 watt incandescent lamps.
The light output is constant over a range of 10 volts to 30 volts, no dimming or flickering with changes in speed.
The much reduced load will greatly increase the battery life, and may permit of a few more years service from batteries otherwise considered life expired.
Anyone here who volunteers as an electrician on a preserved line ?
Although this is a RAILWAY forum, these new LED lamps are also worth considering for vintage buses, yachts, caravans etc.
I have no connection with any vendor of these lamps.