Next to the electrics.
I am attempting pickup from the rails to via a Massoth 8FL decoder (thanks to Muns for the usual super-fast delivery!) to run the lights, mostly so that I can have an automatically operating head light - a bi-colour LED in the front lamp.
To get pickup from the rails I use each bogie to collect one rail. The tyres of one side are shorted directly to the axel. In a little extra complication I use current detection for my computer controlled running so a 10k resistor is added between the axel and the opposite tyre allowing a small current to flow from one wheel to the other which allows the coach to be detected.
Then a pickup (in this case a folded brass picture hook!) was added below the bogie. The washer is there to give a bit more clearance from the chassis.
I had anticipated the wiring requirements and allowed holes in the chassis support when building the chassis...
The decoder was fitted on the underside of the chassis too. This section will have a cover screwed over it eventually (miniature screws on order!).
Interior lighting is currently from grain of wheat bulbs fixed to the brass rods in the top of the coach.
I am also using a Massoth Power Buffer (the old capacitor type), in an effort to keep the lights on during what is unlikely to be perfect pickup. Testing has shown that pickup is indeed very dicey, but the capacitor buffer does a lovely job of smoothing the LED headlight. It will hold it on for around five seconds after removing the coach from the track. However, as soon as the interior lights (5 GOW bulbs) are turned on it really doesn't make much difference any more and there is flickering galore.
I've come up with a few options to try to correct this.
? Replace the GOW bulbs with LEDs - I think this would cut the current draw by about a half, maybe not enough. But I have some LEDs so maybe worth a go.
? Get on of those fancy new power buffers - currently out of stock at Garden Rail Outlet! also a fairly sizeable outlay.
? Butcher the existing power buffer - remove the existing 10000uF capacitor and swap it for a 47000uF super cap (£7 from eBay). Frankly this is a total stab in the dark, I have absolutely no idea if it would work! I guess it might...
? Provide additional pickup from the loco - I'd really rather avoid having cables/connectors running between the two if possible. It would also limit what I can run the trailer with
Any thoughts on that would be appreciated!