Since I have been making “serious” (understand reliable) four-pole electric couplings, I have been gradually equipping certain more or less non-separable trains with them: TEE PBA, Mistral, VB2N. The time has come to do it for these M2 coaches. In the same time, I install new lighting strips, in which the compartment pitch is now respected.
The big advantage of the new couplings is that they allow central control of the lighting and tail lights of the other coaches from the van. In fact, three poles will suffice here. There will even be the possibility of later replacing the reed switches with a function decoder.
This means that three wires instead of two must be passed through the slot in the brass piece above the drawbar. By grouping them together to form a kind of ribbon cable, the flexibility remains sufficient.
It can be seen that the drawbar travel is hindered by the wires neither to the left…
… nor to the right.
The threads are taped to the end wall of the interior fittings.
It was manufactured by JLCPCB. It is designed to adapt to all situations:
To avoid errors when soldering devices, precise markings are placed on the PCB. See markings A (for AB), B, D (for BD). All necessary devices are indicated, even if they are not used in a specific case. For example, in the picture above, devices C1, R2, D2 are only used for the BD coach.
The BD coach has two reed switches: one for the lighting of the train set, located in the centre…
…and one for its own tail lights, located at the end of the van.
The AB coach has a unique reed switch for its tails lights, located at the 1st class end. If a decoder were used, this switch could be removed and replaced by a simple jumper.