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The frequency of a flashing signal

You are here: Home > Forum > Miscellaneous > The real thing (signalling) > The frequency of a flashing signal

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The frequency of a flashing signal 03/08/2013 at 15:27 #47875
pedroathome
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890 posts 		Hi All

This is just a quick question, with (hopefully) a simple answer, but would anyone be able to tell me what the frequency of a flashing yellow aspect is, and also if you happen to know what the flashing green aspect frequency was on the Peterbrough (I think) lines for higher than 125MPH running.

This is just to help me with a model railway project to create the software for a signal capable of this.

[sup]If this is in the wrong place, feel free any admins / mods to move this to where it would be more appropiate[/sup]

James
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The frequency of a flashing signal 03/08/2013 at 15:35 #47876
Steamer
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3924 posts 		According to this document at RGS online:

Quote:
2.2.1.4 Colour light signal lights that are designed to flash shall comply with the following
criteria:
a) Flash at a frequency of 60 (+/-10) cycles per minute.
b) Have a mark:space ratio that provides visibility of the signal light for 50% -
66% of each flashing cycle when observed in accordance with the relevant
standard performance category (see Appendix C).
c) Flash in synchronism within the signal head when the flashing double yellow
aspect is displayed.
d) Flash in synchronism throughout the primary and co-acting signal heads
when flashing aspects are displayed by co-acting signals
"Don't stress/ relax/ let life roll off your backs./ Except for death and paying taxes/ everything in life.../ is only for now." (Avenue Q)
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The frequency of a flashing signal 03/08/2013 at 16:24 #47880
GeoffM
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6287 posts 		Filament signals often take time to fade to black so they can appear to be on longer than the figures Steamer posted.
SimSig Boss
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The frequency of a flashing signal 08/08/2013 at 19:18 #48125
button_pusher
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56 posts 		In SSI areas, the signal module maintains a current to the lamp at all times and the full current is passed to the lamp via a resistor from outputs 0 and 1 (depending on whether it is a single/double yellow aspect. Hopefully the diagram below can explain it slightly better!



(Image from IRSE Red Book)
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The frequency of a flashing signal 08/08/2013 at 19:21 #48126
Stephen Fulcher
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2028 posts
Online 		The same happens in RRI areas as well. I do have a diagram but cannot remember where.
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