1. w4dccqa@groups.io

Re: Coach lighting

Vollrath, Don <dvollrath@...>
 

Yes. Using a bridge rectifier corrects for either track polarity and protects the LEDs from reverse voltage.

DonV

 

From: WiringForDCC@... [mailto:WiringForDCC@...] On Behalf Of Thomas Cockle
Sent: Thursday, January 30, 2014 10:01 AM
To: WiringForDCC@...
Subject: [WiringForDCC] Re: Coach lighting

 




I use a bridge rectifier ahead of the LED lighting (so that when I run at my DC-only club the lights work in both directions).   Since a bridge rectifier is actually four diodes, doesn't this solve the reverse voltage problem as well?

Or should I add another diode?

Tom Cockle

McKinleyville CA

 

 

Wed Jan 29, 2014 7:39 pm (PST) . Posted by:

"Ed S" ed.kolt

Max,

Thanks that makes sense. I will include a diode if I decide to power 
LEDs from the track.

Ed S

At 10:14 PM 1/29/2014, you wrote:
>
>
>LED's will stand only a few volts (5-7) in reverse from the normal 
>polarity for lighting them. If on DCC they are under reverse voltage 
>half the time. If you have 2 or 3 in series the reverse voltage 
>might divide evenly, but very unlikely, so it's best to prevent 
>stressing the LED's by adding a regular diode as well. These are 
>usually have minimum reverse rating of at least 59 volts so more 
>than adequate for DCC track voltage levels. And yes someone may be 
>using them without diodes and so far nothing happened, but that's no 
>substitute for a little proper engineering.
>
>
>
>Max
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