Jump to content

scratch built light towers

Dan Griffin

Recommended Posts

i have scratchbuilt some lighting towers for my yard and tmd. using spare 12v bulbs from Heljan. however, wired up to a conventional 12v dc controller, the illuminate but they get dimmer. they have been wired together, for bulbs per tower, but after 4 bulbs they others do not light. could i run these NON DCC off the constant power supply from my dynamis? or are the bulbs that you can get from expo catalouge better? or is there another way? thanks in advance.

Link to post
Share on other sites


I would highly recommend this power supply for both filament lamps and LEDs (with suitable series resistor)

Maplin 1.2Amp PSU


IMO at under £10 GPB the Maplin variable voltage output 1.2Amp regulated PSU offers excellent value.


While filament lamps will illuminate on either dc or ac at the appropriate voltage, I always recommend where possible using dc and if possible that supply being regulated.


The two reasons are....If you use ac the filament lamps won't last as long as they would on dc! This is because the ac is switching on/off the filaments at mains frequency of 50Hz(UK). Where as dc is a continuous supply, thereby helping to increase the lamps longevity.

Using a Regulated PSU will ensure the output voltage remains constant at what its set at (within tolerances), regardless of the loading placed on that PSU (Up to its maximum loading). Again helping to increase lamp longevity as there should be no sharp rises or dips in the output voltage as found with non regulated PSUs.


Remember... If you connect two 12 volt rated filament lamps together in series then the pair are connected across a 12 volt power supply feed, the two lamps will both illuminate to approx half their normal 12 volt brightness. Also if one of the two does ever fail both in the series connection will go out until the failed one is replaced.


If you want full brightness connect each lamp directly across the power supply feed wires (Assuming the PSU is 12 volt rated). If you used the PSU I linked to and find at 12 volts the lamps are too bright, then you could reduce the output voltage to 9 volts and still get fairly bright lights and increase their longevity considerably!


On a 16 volt ac power supply two series connected lamps will each receive 8 volts and be illuminated to approx 2/3 of the 12 volt rated brightness. Often in reality a 16 volts ac PSU may well be giving a higher output voltage than the rating.

Link to post
Share on other sites

I don't know if it's going to be too much hassle but have you thought about changing the bulbs for LED's as these have a minimal current draw and they have a much longer life span than bulbs.


Rapid Electronics supply transformers for 230v with a variety of different outputs eg: 6v, 12v, 15v etc. These tend to be much cheaper than Maplins and they offer free postage if you spend over £30.



Link to post
Share on other sites


This topic is now archived and is closed to further replies.

  • Create New...