Circut Board In Thomas

[James The Red Engine]

Hello,
I'm working on making a model of Rosie and I am currently using the chassis off a Bachmann Thomas.  I have run into the circut board on the model and I wanted to know what it is for.  Is it the eyes like I've been told?

[ZeldaTheSwordsman]

Yes. It regulates the speed at which the eyes move. Without it, the eyes would go crazy at high speed.

[James The Red Engine]

Ok, well I will not be using the eyes on the model so would it be ok to take out the circut board and hook the wires up direct?

[ZeldaTheSwordsman]

It would, but it's not hurting anything to have it there is it?

[James The Red Engine]

No, but I don't see any reason to have it there if it isn't serving a purpose.

[PerfectPercy]

I understand what you mean (especially if you are converting it into a different engine). I would keep it just in case. Someone else might have all the details as to what it does. I think it is more than the "eye-speed."

[James The Red Engine]

well I plan to give Rosie an open cab so if I were to keep the circut board in then I would have to put it somewhere in the boiler.

Mr. the Bach-man, can you respond about the use purpose of the circut board and if I can remove it or not?

[Chessie Sys. 3022]

How is the board hooked up? Do you have any pictures of the board?

[stevek]

Thomas' circuit board is mounted to his cab roof. The cab roof lifts off fairly easily with a gentle pull and wiggle. Red and black wires come from the wheel electrical pickups. The electric current passes through resistors mounted to the circuit board and orange and gray (or maybe brown) wires take the electric current to the motor. My guess is that the resistors are to protect the relatively small electric motor from damage due to any high voltage surges from a short circuit.

The circuit board does not control eye movement. Eye movement is mechanically driven by the same electric motor that drives the wheels. Eye speed changes directly with engine speed.

[James The Red Engine]

Thomas' circuit board is mounted to his cab roof. The cab roof lifts off fairly easily with a gentle pull and wiggle. Red and black wires come from the wheel electrical pickups. The electric current passes through resistors mounted to the circuit board and orange and gray (or maybe brown) wires take the electric current to the motor. My guess is that the resistors are to protect the relatively small electric motor from damage due to any high voltage surges from a short circuit.

The circuit board does not control eye movement. Eye movement is mechanically driven by the same electric motor that drives the wheels. Eye speed changes directly with engine speed.

So would you recommend that I keep the circut board in Rosie?

[PerfectPercy]

Thomas' circuit board is mounted to his cab roof. The cab roof lifts off fairly easily with a gentle pull and wiggle. Red and black wires come from the wheel electrical pickups. The electric current passes through resistors mounted to the circuit board and orange and gray (or maybe brown) wires take the electric current to the motor. My guess is that the resistors are to protect the relatively small electric motor from damage due to any high voltage surges from a short circuit.

The circuit board does not control eye movement. Eye movement is mechanically driven by the same electric motor that drives the wheels. Eye speed changes directly with engine speed.

What is the circuit board for then?

[stevek]

The circuit board puts resistors inline between the wheel electrical pickup and the electric motor. These resistors limit the current that passes through to the electric motor. I am making an assumption that this is to protect the motor from high current from a short circuit, such as might occur in a derailment, but Mr. Bachmann, or one of our more electrically expert group members, might provide a better reason for the resistors.
The circuit board is not necessary if you convert Thomas to DCC by soldering in a DCC decoder. I would think it would be a good idea to keep the circuit board in your Rosie conversion, pending more expert comment from Mr. B or a more expert group member.