I've got two fine Heljan Class 47s - 47063 in Railfreight trainload construction livery, and 47299 "Ariadne" in BR Blue livery. They're fine models, except for the brass wheels that corode over time...Last year, I purchased two Express Models kits to upgrade the simple light bulbs in the front of these models to more realistic directional LED lights.
Having recently upgraded to DCC, the "DC" kit I'd installed now simply lit all LEDs regardless of the direction of the loco. Express Models would gladly furnish me with new DCC lighting kits for £20 each, but wanting to avoid this cost, I'd have a go at a little rewiring!
Having an A-Level in Electronic Systems, re-jigging the little circuit board shouldn't be too much of a chore I thought. Fortunately for me, armed with a soldering iron, within 10 minutes or so, I had the yellow and red LEDs lighting in the direction of travel, but getting those white LEDs running properly? I could only get the both on at the same time.
The little circuit board supplied with the lighting kit seems to have some transitors on board, but with the circuit tracks not visible, I'm not quite sure how they're connected up. I didn't want to blow them sky high with 16V, so decided to unsolder the white LEDs for now - we'll see if I get more time in the future.
Oh, I set CV55 and CV56 down to 192 to hopefully reduce the voltage on Functions A and B down to 12v, so as hopefully not to fry those LEDs...
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