Machine light

I have Tom Senior milling with the original light fitting. The light is supplied through a step down transformer with a approx 30 volt or 15 volt output. For the last couple of years I have been using 50 Volt standard bayonet lamps, Due to vibrations on the lamp fitting the lamp connections burn out quite quickly, I have rewired the lamp and fitted a small ES lamp holder in the lamp. What lamp bulbs would work using this set up ?

Not quite what you asked, but is it worth considering modern LED lamps? - it may stop the problem of vibration breaking the filaments of standard bulbs. I assume you are using a 50 volt bulb on a lower voltage to reduce this risk.

You will possibly need a DC supply for an LED lamp, but low voltage types are available. The use of DC would also eliminate the risk of 'strobing' as you work under an AC lamp.

I appreciate this entails a little more cost, but may be worth it in the end.

Again, not quite the direct replacement you're after. 12V (3-5W) LED downlighter replacements for 50W halogen jobs make wonderful machine lamps, but don't have the hidden 'advantages' of heating the room or providing a sun tan because they run cool and AFAIK don't emit UV. Currently a bit pricey, but I got a load for about a quid each recently.

Many moons ago,2004/2005 ?,I was over in Chester for one of their "Open Days",and while there I bought two of their machine lights [like mini searchlights ]. Neither light had a bulb,but my friend,who worked in the Motor trade,pointed out that a 24 volt bulb,as used in truck headlamps would fit,and were easy to get in any Motor factors.

Now,2018,those lamps are still working away,on both mill and lathe,bulbs have never failed,but if they do,are easy to find.

Just a thought,might help.

PS Just remembered,they were flogging those lamps for £5 at the time !

Lots of options nowadays, especially with LED stuff

They've even got cordless floodlights nowadays which cost two packets of cigarettes

I'm not paying £40 for a floodlight.

I think Peter is looking for an ES based bulb taking either 15 or 30VAC that will fit into his holder and work with his existing wiring and transformer.

Unfortunately that animal may not exist - I couldn't find a match on the RS Components site and they sell multitudes of different lamps.

May have to look for a different holder and voltage. For example a 12V car headlamp bulb makes a good machine lamp: bright, and they're much happier with vibration than an ordinary high voltage filament bulb. But then you hit the hassle of finding a holder and transformer. The easiest answer is probably to buy a machine lamp and fit it!

No doubt now I nailed my trousers to the mast by saying they don't exist someone will say 15V ES bulbs are as common as muck...

Dave

Hi Guy's.

Thanks for the replies. Will a 12 Volt car headlamp bulb run off 15V ac without blowing. If not I think the best way forward is to remove the stepdown transformer and use the original MEM switch to switch the 240v mains and use an LED low voltage device to power the lamp. The LED device could be mounted in the switch housing where the transformer is now.

It will be unlikely to blow the lamp but the life of the lamp will be shortened, the life of a filament lamp can be improved dramatically if you under run it and shortened if you over run it.

mike

Car alternators charge at around 14.5 volts

They should, but it's DC

One of theses might be worth a punt link

H

You may find you can sell the old lamp for more than a replacement costs. They’re quite collectable and sell well on eBay. I looked at replacing the one on my lathe with a period lamp but after seeing the prices went with led

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Dave,

Forgive the pedantry, please:

I think that Peter's "small ES lamp holder" refers to an SES lamp holder

i.e. a holder for "Small Edison Screw" bulbs ... a.k.a. "E14"

MichaelG.

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Useful link:

https://www.mygreenlighting.co.uk/energy_saving_blog/bulbs/e12-e14-ses-e17-all-fingers-and-thumbs

Edited By Michael Gilligan on 05/11/2018 07:40:50

AC or DC makes no difference with a resistive loading. AC will have higher peak voltage (+ve and -ve) 100 times a second, but the root mean square average will be the same value as a simple DC voltage. Our mains AC voltage (230V) is simply the equivalent of 230V DC, but peak voltage will be 230.2^1/2 = 325V.

230V AC is far safer than 230V DC, mind!

Well, I'm not sure it's pedantic to point out a major technical difference in the specification!

Fortunately for my modesty, I can't find any SES lamps that would suit Peter either. Just as well. The world isn't ready for my knees...

Dave

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I tried a google search for "E14 low voltage" [without the quote marks] and found quite a variety of bulbs: **LINK** for example

https://bedazzledledlighting.co.uk/product-category/led-bulbs/ses-e14/

It does worry me a little that the same fitting is used for both Mains and low voltage; but such is life.

MichaelG.

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Not sure what Peter's exact requirement is; so I wouldn't presume to recommend any particular bulb, or supplier.

Edited By Michael Gilligan on 05/11/2018 11:55:55

Running a filament lamp on overvoltage will decrease its life, disproportionately, (exponentially? ).

So a 24 volt lamp on 30 volts will have a considerably shorter life especially as the initial No Load voltage may well be higher. If you could run the 24 volt lamp in series with something that drops 6 volts when taking the same current as the 24 volt bulb, you would be home and dry. (If you could find one, a 6 volt lamp of the same wattage, or maybe a 12 volt of double the wattage, as the 24 volt worklight?). A resistor dropping 6 volts at the current consumption of the main lamp is likely to become quite hot. Useful as additional heating in the winter, but not so good in the summer!

Hhad the supply been Dc, it might have been possible to find a couple of solid state 12 volt regulators, capable of withstanding the current draw, and connected in series with each other (on a suitable heatsink ), and the 24 volt lamp.

Just a few thoughts

Howard

An extreme case was that of Photoflood bulbs, BRIGHT but shortlived. They were actually 110 volt, but run on 230/240 volts had a life of a very few hours. The current surge on start up was what did the damage. Soft starting on a lower voltage to heat the filament extended life considerably.

Howard

Hi All

I tried an SES 24volt pygmy lamp today, It worked but is not bright enough. I will venture down the LED route. The original 440/125 volt transform will need to be removed. This will free up for a LED driver to be installed into the MEM switch housing.

The future looks bright.