LGB GEii 4/4 R/C conversion

grizzmo

From NW Tas
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Hi all.
I am converting an old (30+years) analogue geii 4/4 to battery R/C.
I have done the install using a micron MR603c receiver, I removed the skates and brushes and tested as is, it runs fine.
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My question is am I missing something in the tests below ?
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This board was connected to the weight in the chassis (motor board for want of a better name) had 3 wires in each side from each motor and pickups, joining to common busbars, white cable rail pick up and motor, brown cable other rail pick up only and green cable motor only.
The diodes and resisters are in the green motor cable circuit.

brown, white and green leave in a 3 pin plug to the body in smaller gauge wires.

supplying 13v dc to brown and white input powers up the directional lights and raises one panto and drops the other. Reversing polarity swaps it over, needs 9v to start, but isn't really happy sitting at 9-11v on changing over. Above 11v it swaps over nicely.

The above board seems to be only for motor control and as a junction for power pick up?
Tracing out the circuit and measuring the voltage, track voltage is fed to the loco body from the plug on the brown and white cables from this board.
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I removed the motor board and put 13v dc directly to the brown and white cables and everything functions the same.
Only difference I see is current draw is lower without the motor board in the circuit.
feeding the motor board, panto's operating was 0.7 amps for 3-4 seconds then 0.2 amps continuous draw for the lights.
feeding joining cable directly, panto's operating was 0.5 amps for 3-4 seconds then 0.15 amps continuous draw for the lights
Is it ok to assume the lower current draw is due to the components on the motor board using some power ?
I think the green wire between boards is a feed from panto if you want to collect power from them.
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I think this board has the switch track power ,off, panto power and is for dropping track voltage, I think these are 5v incandescent lights ?, directional light control and feeds the panto boards.

I can't see a problem with connecting the brown and white cables to the above board in parallel with the motor output cables on a micron MR603c 3A r/c board. Green wire not needed.
I might have to switch them around if lights and panto's operate the wrong way round, there is a 50 % chance of getting it right :)

The current draw should be below 3A max rating, as I have read the current draw on these loco motors is below 2A.
I can join the ammeter in the circuit and run it with the loco to be sure if it is really needed.
To me it would function as it did as a track powered loco.

Can anyone see a problem with doing this, am I missing anything?
 
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You will see a higher current, as the filaments warm-up, and as the panto motor is fired.

Back to batteries, I would use 12 cells (14.4V) which should give plenty of voltage for the auxiliaries, and a sensible top-speed.

You can leave the board in the circuit, but feeding from the motor output, you won't have lights when stationary. - You could split these off, and drive direct from the receiver.

The original board may have used the weight as an additional heatsink?

If using holder for ordinary cells, get some heatshrink, big enough to go round the cells, to hold them in the holders. - If the loco gets jarred, a cell can partially dislodge. This can be a cause of local heating, and over the course of a long run, generate enough heat to start melting/distorting things.
This is one reason we us made-up packs.

PhilP.
 
You will see a higher current, as the filaments warm-up, and as the panto motor is fired.

Back to batteries, I would use 12 cells (14.4V) which should give plenty of voltage for the auxiliaries, and a sensible top-speed.

You can leave the board in the circuit, but feeding from the motor output, you won't have lights when stationary. - You could split these off, and drive direct from the receiver.

The original board may have used the weight as an additional heatsink?

If using holder for ordinary cells, get some heatshrink, big enough to go round the cells, to hold them in the holders. - If the loco gets jarred, a cell can partially dislodge. This can be a cause of local heating, and over the course of a long run, generate enough heat to start melting/distorting things.
This is one reason we us made-up packs.

PhilP.
thanks PhilP PhilP for the quick response.
the motor board did use the weight as a big heat sink.
I am ok with the lights only being on when it runs.
the batteries are cable tied in the holders, do you think that isn't enough?
 
That will be fine...

Just NEVER rely on insulating tape, for anything but temporarily holding / insulating things. - Especially in your climate.

PhilP.
Lol yeah, I have been a sparky for 37 years, we only use electrical tape to mark cables and temporarily tie small stuff on the ute :D
 
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