REWIRING THOMAS

Gavin Sowry

Gavin Sowry

Garden Railroader and Raconteur
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As many of you will know, Thomas is wired to run opposite to the normal way we do things.

I finally took him apart with the intention of 'just swapping the terminals over', but noticed some 'added extras' mixed up in there. Is it just a simple case of swapping everything over, terminal for terminal, or, do those 'extras' have some effect on something (the eyes, perhaps) else.
 
Gav,

While I haven't done precisely this, two or three years ago I converted Thomas to battery r/c and in the process made him work the same as all the other controllers I use for my locos (not that there are that many, but you get the idea; "forward" is "forward" for all of them). I just disconnected the track pick ups and wired the r/c into the terminals they were connected to; getting the directional control right by testing them. Worked, and works, fine.

Steve

(and I'm having grammar challenges this morning, must be Monday...)
 
If you can get at the motor terminals where they connect to the motor, swap them there, or does it have directional lights?
 
My TTE (which was bought in 2014) has a polarity change switch underneath so no need to re-wire. Well that was until I made it battery rc with sound.
 
Rhinochugger said:
or does it have directional lights?
Click to expand...

No lights, but two wires to each terminal and a 'something' attached to some of the wires (diodes, resistors.... ???).
 
I would check again for a NMRA / Large Scale switch..

Unless of course you are going battery, then probably rip it all out??
 
On mine the switch is by the offside rear wheel. It says "polarity" . I will post a photo in an hour or so
 
Gav,
Gavin Sowry said:
No lights, but two wires to each terminal and a 'something' attached to some of the wires (diodes, resistors.... ???).
Click to expand...

Gav,

Try PM'ing Tony Walsham, he knows what that board does. He told me once in a post, but I'm ashamed to say I'vd forgotten.


Steve
 
Robert H said:
The polarity switch is not present on the models from starter sets :)

Missing from my one as well...
Click to expand...
Interesting.. As the one at the Chasewater came with Annie, Claribel, track, controller etc. Presume that is what you mean by a starter set?
 
Gavin Sowry said:
No lights, but two wires to each terminal and a 'something' attached to some of the wires (diodes, resistors.... ???).
Click to expand...

Little brown circular blobs?

Capacitors - stops you getting interference with your TV picture. They can stay as they are :D
 
The pcb on the end of the motor is for motor "noise" suppression.

Just visible in the top LH corner here.

13.jpg


It can stay there.
 
How strange is that? This is mine from underneath. The bright coloured switches were added by me for battery radio control.

tte1.jpg

tte2.jpg

My TTE was the last purchase I made from Steve Warrington so it has now become special.
 
Tony Walsham said:
The pcb on the end of the motor is for motor "noise" suppression.

Just visible in the top LH corner here.

13.jpg


It can stay there.
Click to expand...

OK, got the bit about them yellow blobs. What concerns me, is those black 'thingies'. What are they, what do they do, and what effect would changing wires over have?
 
Tony Walsham said:
They are RF chokes. Used to help suppress RFI.
No effect whatosever.
Click to expand...

So, they are not polarity sensitive?.. or anything like that?

Just unsoldering the feed wires, and swapping them over, would fix things OK?
 
That is what I did on my 2010 Thomas and later on Percy. James, Emily and Toby all came later and with the switches.

If you think about it, Thomas is designed to go backwards and forwards so those chokes can take either polarity.

I have also fitted my own Thomas locos with two parrallel strings of diodes to one side of the supply to drop some voltage to the motor, so that Thomas and co will perform more like my LGB and Playmobil locos, rather than Formula 1 racing cars.

I have used two strings of two or three diodes in series. One sting is wired one way, the second the opposite way round, them both are wired together in parralel. This makes Thomas slightly slower, but still reversible.

Like this:
>>
___ ___

<<

I really need one of those funny shaped bracket things to show how the two sets of diode are the linked to the wire that goes in and the one that goes out......Best I can do.....

Yes I know I could just run it on less voltage, but my layout is automated, so I need the locos to behave in much the same way at the same voltages....

James
 
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