R406 Signal Lights

[Kidcurry]

Hi.

I would like to add a few R406 lights to my layout.

I am going to power all points using the Hornby DCC accessory units and would like to know if I can "piggy back" the light to the point wires. eg. Red lamp to one and Green lamp to the point motor wires.

Plan is: the points are thrown and the lights change automatically.

Is this possible.

thanks

regards

Steve

[Chrissaf]

"Is this possible?".

Not directly. The R406 signal lamps need a permanent power supply. The output ports of the DCC Accessory Decoder used to operate solenoid points use 'pulses' of power. Thus if you were to piggyback the R406 across the solenoid wiring, the R406 lamps would only flash once and go out. It is also possible that parallel wiring of the R406 having different electrical characteristics to a solenoid, could actually prevent the solenoid from operating at all.

Your options are:

1. Replace your point motors with ones that have an integrated change-over electrical contact that can use a separate external power supply to operate your R406 signals.
2. Add a mechanical change-over switch to your current point motors to use with a separate power supply.
3. Add a latching relay product to your Solenoid motor that is designed for this purpose of operating a signal via a separate power supply. Guagemaster make two versions. The GM500 when the Accessory Decoder is using 'common negative' to operate the point motors and the GM500D when the Accessory Decoder is 'common positive'. The Hornby R8247 Accessory Decoder is 'common positive'.

Note that in all three options above, the need for a separate external power supply is consistently common to all three options. I would suggest that this should be a general purpose 12 volt DC power supply with a suitable current capability chosen to support the number of lamps you want to operate. The older R406 signals used bulbs rather than LEDs, thus they need more current. Typically about 70mA per signal.

[96RAF]

In support of Chris advice - this is Appendix 6 to the R8247 Rev 2 manual.

second from the bottom is the latching relay solution.

[Chrissaf]

Gaugemaster GM500D info

Universal Relay Switch (DCC Friendly)-Gaugemaster-GM500D

[Kidcurry]

Hi Chris and 96RAF

Once again, many thanks for your assistance. Most helpful.

Kind regards.

Steve

[96RAF]

If you have the old filament bulb R406s then forum member Son of Triangman sells an LED conversion kit in various colour-ways of red - green - yellow.

Search for Norfolk Coast Models.