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Discussion Boards => General Discussion => Topic started by: PrairieDub on January 14, 2019, 12:14:28 PM



Title: HO GP40 Motors
Post by: PrairieDub on January 14, 2019, 12:14:28 PM
What is the difference between HO GP40 motor with resistors Part # 63525 and without resistors Part # 63525-1?

Thanks!


Title: Re: HO GP40 Motors
Post by: rich1998 on January 14, 2019, 01:25:26 PM
https://estore.bachmanntrains.com/index.php?main_page=product_info&cPath=68_185&products_id=1295

Although they are called resistors, they are ferrite inductors, or called chokes. All Bachmann DCC locos come with them. Mime did. Some had wire wound inductors.
Good spotting.
They are 4.7 Microhenry (ÁH) chokes, inductors that form a tuned circuit to satisfy the UK and EU. Bachmann sells may DCC locos other that side of the Pond. Check the colored stripes on the Internet.  They filyer out a frequency, frequencies.
I have a LRC meter and it measured the inductance also. They have no resistance.
The person who labeled the page had no idea. Many modelers have no idea either. I have seen this in other forums.
Many rip them out and solder in a piece of wire.
Rip out the caps as the inductors have no resistance and are a moot point. With a quality decoder, the BEMF affects slow speed.

Rich


Title: Re: HO GP40 Motors
Post by: PrairieDub on January 15, 2019, 03:05:19 PM
Thanks for the information.

Electronics isn't my area of expertise, but it's good to know why the wiring is like it is, and what purpose it serves.

I've got another post called "HO GP40 Motor Constant Screeching"...do you have any idea what might be causing the screeching?


Title: Re: HO GP40 Motors
Post by: rich1998 on January 15, 2019, 04:54:15 PM
It does sound like a mechanical issue looking at the discussion. Screeching sounds unusual but I guess the OP's definition of what he is hearing.

Rich


Title: Re: HO GP40 Motors
Post by: rich1998 on January 15, 2019, 05:05:14 PM
here is a little on the caps and inductors that most miss in the Bachmann site.
Mark has a lot of good info about DCC you should keep. Bookmark the URL.

https://sites.google.com/site/markgurries/home/technical-discussions/decoder-motor-drive/motor-capacitors/bachmann-engines

One time in a search, I found a couple forums in the UK that said, keep those devices in place, "over there".

Rich