Hardware

LoDi-21MTC(-S)

The LoDi-21MTC(-S) board

The LoDi-21MTC(-S) board. Would you like to convert your old locomotives simply and quickly, without having to do without the latest decoder technology?

With the LoDi-21MTC board, converting older locomotives cleanly and quickly is child's play . . .

And now even the LoDi-21MTC-S board with built-in series resistors ! ! !

When converting locomotives you want to be as flexible as possible.

That is why we developed the LoDi-21MTC(-S) board and brought all 21 poles out to solder pads.

It is suitable for boards with or without sound.

Features of the LoDi-21MTC board

A simple 21-pin MTC interface for all common 21-pin locomotive and sound decoders
A space-saving design
All poles brought out to solder pads
Independent of gauge or two- and three-rail system

1. The LoDi-21MTC board and its connections

LoDi-21MTC(-S) — The LoDi-21MTC board and its connections

Connection information, NMRA colour scheme:

TR-R = right-hand rail = red
TR-L = left-hand rail = black
MOT 1 = motor right = orange
MOT 2 = motor left = grey
LV = front light = white
LH = rear light = yellow
U+ = shared + = blue
AUX1 = switchable channel 1 = green
AUX2 = switchable channel 2 = purple
LS− / LS+ = loudspeaker = brown

An example wiring diagram with a locomotive. Front and rear lights with directional lighting, switchable through AUX1 and AUX2.

Connection information, Märklin® colour scheme:

TR-R = right-hand rail = red
TR-L = left-hand rail = brown
MOT 1 = motor right = green
MOT 2 = motor left = blue
LV = front light = grey
LH = rear light = yellow
U+ = shared + = orange
AUX1 = switchable channel 1 = brown-red
AUX2 = switchable channel 2 = brown-green
AUX3 = switchable channel 3 = brown-yellow
AUX4 = switchable channel 4 = brown-white
LS− / LS+ = loudspeaker = white

The LoDi-21MTC board has further outputs which can be used differently depending on the manufacturer, such as SUSI or further AUX or logic channels.

CAREFUL! The board must not be mounted directly onto the metal of the locomotive; the locomotive and the board have to be insulated from each other. For a perfect fixing, use foam adhesive tape to fasten the board in the locomotive. Using double-sided adhesive tape also ensures the locomotive body and the board are insulated.

2. The LoDi-21MTC-S board and its connections

On the LoDi-21MTC-S board we have done without the higher outputs such as AUX6–AUX12. These are mostly logic outputs or are used in manufacturer-specific ways.

We have used the space for series resistors. That means the board can be used directly in locomotives with LEDs. You do not have to add any resistors on top.

LoDi-21MTC(-S) — The LoDi-21MTC-S board and its connections

Connection information, NMRA colour scheme:

TR-R = right-hand rail = red
TR-L = left-hand rail = black
MOT 1 = motor right = orange
MOT 2 = motor left = grey
LV = front light = white, 1k built in
LH = rear light = yellow, 1k built in
U+ = shared + = blue
AUX1 = switchable channel 1 = green, 1k
AUX2 = switchable channel 2 = purple, 1k
LS− / LS+ = loudspeaker = brown

Here we have now fitted LEDs with directional lighting in the locomotive, using 4 light channels. On the LoDi-21MTC-S, 1 kilohm resistors are fitted at F0V/H as well as at AUX1 and AUX2. You therefore do not have to fit any additional resistors for the directional lighting in the locomotive.

Connection information, Märklin® colour scheme:

TR-R = right-hand rail = red
TR-L = left-hand rail = brown
MOT 1 = motor right = green
MOT 2 = motor left = blue
LV = front light = grey, 1k built in
LH = rear light = yellow, 1k built in
U+ = shared + = orange
AUX1 = switchable channel 1 = brown-red, 1k
AUX2 = switchable channel 2 = brown-green, 1k
AUX3 = switchable channel 3 = brown-yellow
AUX4 = switchable channel 4 = brown-white
LS− / LS+ = loudspeaker = white

In this example we have removed a board from a Märklin locomotive and left the original LED lighting in place. The series resistors would now be missing here, which we now have again with the LoDi-21MTC-S, so no additional resistors have to be added.

Here is a small example of the LoDi-21MTC-S in a Märklin Köf, where the old Motorola decoder is removed and replaced by a 21-pin decoder of your choice.

3. Technical data

LoDi-21MTC

0–24 volts AC, DC or digital

Dimensions

Length: 23 mm

Width: 16 mm

Height: 13 mm at its highest point (can vary from decoder to decoder)

Weight: 2 g

LoDi-21MTC-S