Bachmann 21 pin Dcc socket wiring ?

[amdaley]

Hi Everyone.

 

Hope everyone is keeping well.

 

I have a Bachmann 21 pin Dcc socket which has 4 black wires connected to it.

They are connected to the connections R+, L-, L1 & L2.

Can anyone tell me which connection refers to the standard Red, Black, Orange & Grey Dcc connections.

I have enclosed a couple of photos.

 

 

 

Thanks everyone & take care.

Tony.

[jpendle]

I would hazard a guess that Red and Black are R+ & L- and that Orange and Grey are MO+ & MO-.

 

Regards,

 

John P

[Nigelcliffe]

A multimeter buzzing the wires to the pins on the MTC21 connector would prove John's intelligent guesswork.    The MTC21 is a standard, so easy to look up online.  

[amdaley]

8 hours ago, jpendle said:

I would hazard a guess that Red and Black are R+ & L- and that Orange and Grey are MO+ & MO-.

 

Regards,

 

John P

 

Thanks John.

Is there any way I can make sure of this ?

 

2 hours ago, Nigelcliffe said:

A multimeter buzzing the wires to the pins on the MTC21 connector would prove John's intelligent guesswork.    The MTC21 is a standard, so easy to look up online.  

 

The connector is disconnected from the cables Nigel.

There are plenty of images online of the MTC21 but none which show the Bachmann one or explain what R+, L-, L1 & L2 mean ?

Could someone point me in the right direction ?

[Brian]

21MTC pin out is .... Pin 22 Track Red. Pin 21 Track Black.  Pin 19 Motor Orange and Pin 18 Motor Grey.

 

Therefore I think you will find that by testing from Pin 22 it should connect to the wire on R+.    Pin 21 should test to L-.   Pin 19 should test to L1 and Pin 18 should test to L2.

If that doesn't test correctly, then simply connect the meter or testing device to one wire and see if you can pick up the connection on a specific pin! Do the same for the other three wires.

 

 

 

Edited April 26, 2020 by Brian
Image added

[John ks]

This circuit board is missing a few components I.E. L1 L2 C1 & C2 & these components are not necessary for the decoder to work

Because the Inductors L1 & L2 haven't been installed  the motor connects to the holes next to L1 & L2 not to the MO+ & MO- holes

the connections are 

MO+ Hole Marked L1

MO- Hole Marked L2

Left rail       L- ( not 100% sure but it is the only one could be. Couldn't follow the trace on the PCB as it is in shadow)

Right rail     R+

The pics might give you an insight into how I reversed engineered the PCB 

The circuit shows how the extra components would have been connected

 

 

John

 

 

[amdaley]

Thank you everyone for your assistance.

 

As a result of testing I have established that

 

R+ = Track Red.

L- = Track Black.

L1 = Motor Orange +

L2 = Motor Grey -

 

Regards Everyone & stay safe.

Tony.