Heljan O Gauge 37

[Clifford Road]

Morning all,

I'm fitting an SWD Loksound XL decoder to my O gauge 37. Steve at SWD has said to use a 47k resistor on the front and rear white lights and a 33k resistor on the tail lights. Which is fine, no problems. However, not being electronically minded, there are so many different types of resistor - from metal film to carbon! Is there any difference? Can anyone recommend a shop/supplier who sells them?

 

Looking at ebay I've come up with this 47k resistor and 33k resistor. Can anyone say if these will be ok?

 

Thanks in advance!

 

Rich

[Clifford Road]

Hi all,

In case anyone needs to refer to this topic in the future - for the built in Heljan lighting its a 1k resistor - for SWD's own lighting kit for the O gauge Heljan 37, its a 33k and 47k resistors as included with the kit.

 

Cheers

Rich

[Nigelcliffe]

Sorry, missed the thread earlier.

 

Metal film vs Carbon film. For a given power rating, metal film resistors tend to be smaller physically - important in 2mm/N, handy in 4mm/00, less important elsewhere.

Resistors come with a power rating, but at the resistances quoted (all above 1k, and most 10's of k-ohm), the power to be handled in current limiting for LEDs is not usually a significant issue.

Resistors come with an accuracy, expressed in percentage. For LED current limiting, its not important to use 1% accurate resistors.

 

I bought a big pile of mixed carbon film resistors from Rapid Electronics (I cycle over to my local shop!). Those will last ages. If I use up any particular size, I restock with a packet of 50 or 100, which will last for a very very long time.

[Clifford Road]

Sorry, missed the thread earlier.

 

Metal film vs Carbon film. For a given power rating, metal film resistors tend to be smaller physically - important in 2mm/N, handy in 4mm/00, less important elsewhere.

Resistors come with a power rating, but at the resistances quoted (all above 1k, and most 10's of k-ohm), the power to be handled in current limiting for LEDs is not usually a significant issue.

Resistors come with an accuracy, expressed in percentage. For LED current limiting, its not important to use 1% accurate resistors.

 

I bought a big pile of mixed carbon film resistors from Rapid Electronics (I cycle over to my local shop!). Those will last ages. If I use up any particular size, I restock with a packet of 50 or 100, which will last for a very very long time.

 

Hi Nigel,

Thanks for the reply - that's helped make things clearer in my mind ... all very confusing to a non electronic tecky!!! Do you find that one type tends to last longer than the other ... or isn't there much of a difference? I'm guessing the latter?

 

Rich

[boxbrownie]

Rich, although the Heljan are indeed running around 1k, there are two resistors (for some reason best known to Heljan) in each lighting circuit, there are the board mounted resistors and there is a resistor actually in the wire loom at each LED end. I cannot remember which way there are at the moment but from memory one is 470 and the other 333 or there abouts.