[TCUG] Re: LED Heads
- From: "Richard Berry" <richard.berry5@xxxxxxxxxxxxxx>
- To: <tcug@xxxxxxxxxxxxx>
- Date: Thu, 16 Oct 2003 13:24:17 +0100
I believe Dave is right and that it is Siemens that have ramped the
switching to mimic TH lamps. The problem described sounds as though the
heads in question have a mix of lamps or perhaps even versions of LED
aspects
Richard Berry
> -----Original Message-----
> From: tcug-bounce@xxxxxxxxxxxxx [mailto:tcug-bounce@xxxxxxxxxxxxx]On
> Behalf Of David B Thompson
> Sent: 16 October 2003 09:43
> To: tcug@xxxxxxxxxxxxx
> Subject: [TCUG] Re: LED Heads
>
>
> Most LED's that I have seen installed have the opposite problem,
> where the
> change is very "crisp". This can sometimes look odd where there
> is a mixture
> of normal lamps and LED's, for example where the LED's have been used for
> high level signals.
>
> I do seem to remember that at least one of the newer LED heads,
> from either
> Siemens or PEEK has been made to look more like a tungsten lamp, by using
> the "on board" microprocessor chip to give more of a ramp to the
> switch on
> and switch off of the lamp.
>
> The only other time I have seen all lamps on together on tungsten lamp
> sites, is where there was a loose common neutral in the head/polecap. I
> would not have thought LED's would be affected in the same way.
>
> Dave
>
> ===== Original Message from tcug@xxxxxxxxxxxxx at 15/10/03 17:24
> >Hi All,
> >
> >Does anyone have any issues with latency on LED Heads? Here in
> Warrington,
> >we have just installed our first LED signal heads and have
> noticed an issue
> >due to delays in aspects extinguishing. We are witnessing
> situations where
> >for approx. 600ms all aspects are illuminated on a change from
> Red/Amber to
> >full green. Anyone have any thoughts?
> >
> >Andy Ashton
> >Design & Implementation (UTC)
> >Warrington Borough Council
> >
> >
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> jdt
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