Hi Folks,
I wonder if anybody with some electrical knowledge can advise me on a problem I am having?
I am sorry it is a bit long winded but I am sure that giving the complete scenario will be helpful.
I thought it might be a good idea to put lights in my old Triang and Hornby coaches. Not being able to find any replacement coach wheels with a "live" axle I purchased some of the current replacement coach wheels made by Hornby.
As the wheels are all metal and the axle is metal I obtained the ones with two holes in the wheel. I took some single strand stiffish wire, as used in internal telephone extension cable, and poked it through the hole in the wheel, (inside to outside), and bent the end onto the face of the wheel. I then wound the wire tightly about six times around the axle and squeezed the wire onto the axle. The new wheel sets were put into the coach bogie without problem as the old ones were plastic with pin point axles. The wheels were set with one "live" wheel on each side of the track.
Next I secured some pickup wire to the bogie using a small screw and cut a length of the wire to rest on the axle. Under the screw was a small square of phosphor bronze to which I had soldered a wire which was fed inside the coach via the hole through the bogie rivet. The same process was applied to the other axle. This was repeated on the other bogie.
Inside the coach I fixed three grain of wheat lights in parallel connected to the wires from both bogies. In this way the lights were fed electrically from two different directions albeit the same source, i.e. the rails.
I did something similar with another coach but used three LEDs in series, instead of the GOW, using a bridge rectifier and a 1K ohm resistor.
In both cases the lights picked up the current from the track whilst stationary but as soon as the coach started to move the lights start to flicker, even on a portion of straight track. I would have thought that with the lights being fed from two directions the supply would have been constant with two wheels being in contact with the track so if one lost contact the other would keep the supply going.
This is on normal 12v DC; the track was cleaned with a rubber and track cleaning fluid; the wheels are brand new so no muck on them.
Any suggestions to resolve this would be appreciated.
P.S. Is it necessary to oil pin point axles in plastic housing?
Regards
Jack.