Eastern Railroad Discussion > PRR PL signal question

Technical question.  What was the voltage used in this system?  I seem to remember that as originally installed it was a 32 volt system.  Does anyone know if that is correct and was the system modified in later years to a more conventional voltage, like 120 volts?
Thanks,
Doug

I don't know what their system is, but most if not all signal systems today run on 12vdc, using 10v25w signal precision bulbs and LED's.

No signal systems supply lamp voltage at 120 volts. Lamps are usually lit at 10V DC...

CG Tower

611Doug Wrote:
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> Technical question.  What was the voltage used in
> this system?  I seem to remember that as
> originally installed it was a 32 volt system. 
> Does anyone know if that is correct and was the
> system modified in later years to a more
> conventional voltage, like 120 volts?
> Thanks,
> Doug

I seem to recall the lamp voltage would change with the time of day, higher voltage during the day, lower at night
 

NixonRocks Wrote:
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> I seem to recall the lamp voltage would change
> with the time of day, higher voltage during the
> day, lower at night
>  

Perhaps with incandescent bulbs though not all of them have this capability....LED, for their part have a trigger voltage below which they will not make light...and while there is dimmable technology for LED's I do not see it used in signals....the ones I am exposed to are quite bright at night....