Heljan Class 07 shunter sound - lighting protection?

[zr2498]

I am just getting around to fitting sound to the Heljan 'ICI Langbaurgh' 07.

I have a Zimo decoder (now it is the MS490F) from Digitrains with their sound file. Also a Lais stay alive which has gone into the chassis under the rear body, and the speaker will go on the floor of the cab.

As this has to be hard wired, the existing PC board will come out completely. I notice on the YooChoos desciption they mention adding resistors to protect the LEDs. Does any one know if that will be necessary and if so what (small) resistors should be used.

I am basically following the install done by Paul Chetter in Hornby magazine May 2020, but he does not mention extra resistors for the lighting LEDs.

 

Dave

[Nigelcliffe]

13 minutes ago, zr2498 said:

 

As this has to be hard wired, the existing PC board will come out completely. I notice on the YooChoos desciption they mention adding resistors to protect the LEDs. Does any one know if that will be necessary and if so what (small) resistors should be used.

 

 

What resistors were present on the locomotive PCB which has been removed ?   That gives you the answer....    

 

[zr2498]

13 minutes ago, Nigelcliffe said:

 

What resistors were present on the locomotive PCB which has been removed ?   That gives you the answer....    

 

Thanks @Nigelcliffe On the PC board there are only S1G diodes. Then there is the same S1G diodes and a resistor on the blanking plug (which would come out anyway).

I have just had a look under the foam of the LED lighting boards and 'hey presto', the restistors are there so no need to add any.

Sorry, I should have checked this before asking, but appreciate your help.

Dave