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Dorman Watch

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David Dunning

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Just wondering if there was any interest in having a thread which mentions the new locations of the led signals that are cropping up all over the place. They seem to be sprouting like daffodils in spring . Anyway we will soon find out if there's any interest :D

York
Platform 10 and 9 Northbound
 
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swt_passenger

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Isn't it a bit late after so many years of full LED installations? IIRC the Portsmouth area resignalling 2006/7 was considered unusual in using conventional signals, LEDs had been going in for ages before then.

There's also VMS lightweight LED signals being installed as well of course.
 

Cherry_Picker

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Every resignalling project over the past six or seven years has seen incandescent bulbs replaced by LED signal heads. Even limit of shunt signals in unused sidings were replaced en masse because the cost of installation was more than offset by the lower ongoing maintenance costs as the life of a LED is measured in years (if not decades) rather than hours. A LED uses considerably less electricity too as it doesnt really generate heat so there is significantly less waste. In fact, I'd wonder if LED signals were in the majority these days?
 

David Dunning

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yes i guess so . I was thinking more about the way they crop up in areas where the majority of signals are not Led . So at Wavertree Technology Park i noticed they are there east bound but not westbound for example . and at York station you have just two at the moment. The first two coming into Seamer from York are still old ones . Is there a rolling programme of spot replacements ?
 

Hudds_Bungle

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I think it's mainly down to how the S&T lads go about replacing the signals, usually it starts with the easiest first, whether that's ease of access or if it's a basic signal compared to a route indicator/permissive working signal. They have to be canny how as to which they replace first, after all you don't want a driver to mistakenly read thro a bulb type coz the LED type behind it is brighter....:D
 

DarloRich

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yes i guess so . I was thinking more about the way they crop up in areas where the majority of signals are not Led . So at Wavertree Technology Park i noticed they are there east bound but not westbound for example . and at York station you have just two at the moment. The first two coming into Seamer from York are still old ones . Is there a rolling programme of spot replacements ?

It could well be that when a signal head needs replacing it just gets a LCD head. As Cheery Picker says they are MUCH cheaper to run and last for ever!
 

Railsigns

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Isn't it a bit late after so many years of full LED installations?

Yes, it is a bit!

There's also VMS lightweight LED signals being installed as well of course.

and Dorman lightweight LED signals
and VMS non-lightweight LED signals
and Howells LED signals
and Invensys LED signals
and Signal House LED signals
and LED inserts replacing the lamps in conventional colour light (and semaphore) signals
 

HSTEd

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Surely this sort of thing, especially LED replacements for existing lamps inside existing signals, should be accelerated to the highest possible rate?

The energy use by signalling equipment must be rather large.
 

swt_passenger

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Do replace LED assemblies operate at the same supply voltage as filament lamps, or would an LED 'lamp' fitted in an existing housing require an additional or different power supply?

Perhaps there are changes needed to lamp proving circuits as well? (Whatever their correct name is...)
 

John Webb

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Do replace LED assemblies operate at the same supply voltage as filament lamps, or would an LED 'lamp' fitted in an existing housing require an additional or different power supply?

Perhaps there are changes needed to lamp proving circuits as well? (Whatever their correct name is...)

The 'plug-in' replacements run at the same voltage as their filament predecessors and, so I am told, incorporate appropriate circuitry for lamp-proving etc. There has been some discussion on these at:http://www.signalbox.org/forum/viewtopic.php?f=6&t=3151 for those with a technical interest.
 
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swt_passenger

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The 'plug-in' replacements run at the same voltage as their filament predecessors and, so I am told, incorporate appropriate circuitry for lamp-proving etc. There has been some discussion on these at:http://http://www.signalbox.org/forum/viewtopic.php?f=6&t=3151 for those with a technical interest.

Thanks for the link John.

Interesting to see in the 'howells' description that they use the existing lamp holder as the positional support for the unit, but use flying leads to make the connections, bypassing the spring contacts for better reliability.
 

John Webb

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Thanks for the link John.

Interesting to see in the 'howells' description that they use the existing lamp holder as the positional support for the unit, but use flying leads to make the connections, bypassing the spring contacts for better reliability.

Yes - the lampholder is set up at the factory and is sealed in place by a lock-wire through the fixing screws, so that the lamp filaments are located correctly - or in this case the LED 'engine' when used. I must admit I'd missed the bit about flying leads, though.
 
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