Mic Xformer Wiring Diagram

[Phrazemaster]

Hi, I have a german datasheet for a mic transformer. I don't really understand the nature of the brown wire (labeled br). I tried googling xformer wiring diagrams, but I'm still not clear. Is this some sort of ground wire? And why is it shown in dotted lines? What is traditionally done with this wire in a circuit? In the schematic I have, there is no listing of what to do with the brown wire, and the schematic is for this xformer.



Thanks for any responses.

 

[[silent:arts]]

it is a screen / isolating winding.
connect it to ground.

 

[Phrazemaster]

Thank-you! There are 2 brown wires on the xformer; I'll connect both to ground then.

Since you are so kind, allow me to ask another question about this. The schematic shows something interesting that is incomprehensible to me. It says (in German) that the xformer is switchable from 50R - 200R. But I cannot understand how this occurs internally in the xformer. The blue/white wires are shorted (checked with my DMM). I see no way to connect them differently since the xformer is closed.

Just what is the meaning of the internals circled in red? All those criss-crossing wires. They sort of look like a switch, with the open/solid dots on the wires, but I don't get it.

Sorry if this is obvious to the initiated; I'm just trying to come up with what this means. This is a snatch from a U47 schemo.

Thank-you kindly.

Mike

 

[[silent:arts]]

The red circled is a switch - connecting both secondaries either in series (200R) or either in parallel (50R)

 

[Phrazemaster]

Thank-you. I assume to make a switch, you'd have to cut into the xformer wirings. Based on the actual transformer, the secondary wires are already connected (they are "hard wired" into the xformer itself). See attached pic. I assume this is because normally the xformer is used in one configuration.

Does that sound right?

Thank-you.

Mike

 

[[silent:arts]]

Why not leave it as it is?
You would never use that switch anyway ...

 

[Phrazemaster]

Fully agreed! I would hate to cut into that pretty little thing. I just wanted to make sure I understood what was going on. You've helped me a tremendous amount! Thank-you [silent:arts]!