SMD LED lighting for loco

Past week a first step was made to get some LED lighting on the two Roco cargo loco”s I have. They have only one headlight, a light bulb (well, actually 2, one for each direction). On the buffers there’s the ‘suggestion’ of lights. The red tail lights are just paint. The white headlight is brought there via a plastic light transmitter, but in daylight it can not be seen and in the dark it is only very faint.

100 (5 colors, 20pcs each) SMD LED’s size 0603 were ordered at Aliexpress for just €1,10, free shipping. They’re just grains of sand, but they needed to be small in order to fit inside the lamp holders on the loco. With the help of fellow club member Willy, who had all the right tools and materials like a mini soldering station and lacquered wire, 5 LED’s were wired and then placed in and on the loco. It was a first test to see if it is doable and if it looks OK.

What are the results of this test?

First that it was not that easy. It took several hours of fumbling and looking through a magnifying glass. 🙂 But once done, it looked quite promising for a first prototype. On the image the LED’s can be seen. To have it really neat I should drill a hole from behind and place them there. But actually, from a normal viewing distance the LED’s are not very obvious, even more when you don’t know about them. The wire can still be bent and put out of sight a bit, but I did not dare touch it anymore when finally all was in place! 🙂

Second, that the light looks quite OK. With a resistor the current was reduced to a meagre 0.3 mA (!) and even that still seems too much, the light is still too bright. But that can be further tuned via a CV value. The upper LED seems to burn less bright, but that is due to it being inside the housing behind a plastic light transmitter and a lens. The mini LED is like a point light, while the original bulb is very much larger and light a bit better from the inside. This can still be improved some probably.

The images give a bit of an impression. I find it hard to capture the right atmosphere of LED’s on a picture. Luckily in reality it looks much nicer than the images suggest.

Anyhow … it was a nice couple of hours of tinkering. Test result is good enough to now do 5 more LED’s for the other direction of travel and then 2×5 more for the other loco.