Ringfield Motor [DCC Conversion]

[Chrissaf]

hi can anybody help me please 

I have a class 43 hst and its only got two poles on the motor how do I make this dcc with a four pin decoder 

Thanks guys 

[Chrissaf]

....its only got two poles on the motor...

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I assume you mean that the motor has two terminals [for wires] on it.

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What follows is just a very high level basic overview.

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Drawing 1 - This shows that in principle in any DC Analogue locomotive that there are two electrical paths. One between the Left Wheel Pickups and the Left Side of the Motor and the other path on the right hand side between wheel pickups and the motor.

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Thus an electrical circuit is created that goes from the controller via one track rail to one side of the motor, through the motor to the other track rail then back to the controller.

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Now subject the the loco model, type, age, design etc. These two electrical paths might not be totally obvious when the loco is taken apart. Some locos use parts of the metal chassis to act as one of the electrical paths. But generally, if you can see two very separate and distinct wires connected to the motor, then that is usually an indicator [but not a guarantee] that both wheel to motor path sides [left & right] are formed via wires.

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To fit a decoder, you have to break both paths of the electrical connections to the motor and insert the decoder between the two connections to the wheel pickups and the two connections to the motor. This is why the decoder has four wires.

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Drawing 2 - this shows the circuit in drawing 1 modified to fit the decoder.

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/media/tinymce_upload/fb51ce3abd4c573c4baf1802c7e9f3b1.jpg

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The four colours Red, Black, Orange & Grey on the decoder are industry standard. Thus the connection of these four wires need to follow the connections depicted in Drawing 2 to the letter.

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As I said, in my opening to this reply. The information described above is just very high level and basic as a concept. The nature of the internals within your 43 HST will determine the details of the exact procedure needed to perform a conversion.

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Now you have indicated that the motor is a 'Ringfield'. Some 'Ringfields' are easy to convert to DCC, but some others are not, and need an electrical modification to isolate the motor electrical terminals.

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This website goes into the various 'Ringfield' types and what is involved to perform a DCC conversion:

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https://www.brian-lambert.co.uk/DCC_Page_1.html#Bookmark12

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If you are going to perform your own DCC conversions then you really do need to invest in the purchase of a Multimeter so that you can use the Resistance / Continuity meter measurements to prove that you have completely electrically isolated the motor from the chassis and the wheels. If you don't do this, then you will 'fry' any decoder that you fit. Cheap Multimeters can be purchased from eBay for less than £8 delivered, so there is no excuse for not getting one.

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TIP: As a newbie poster on the forum, just be aware that the 'Blue Button with the White Arrow' is not a 'Reply to this post' button. If you want to reply to any of the posts, scroll down and write your reply in the reply text box at the bottom of the page and click the Green 'Reply' button.

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Particularly as my reply includes an image, using the 'Blue Button' may result in your reply being held back for image approval, even though it is an existing image.

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See also – further TIPs on how to get the best user experience from this forum.

https://www.hornby.com/uk-en/forum/tips-on-using-the-forum/

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[96RAF]

As is explained on the Brian Lambert site, ringfield motors can use the motor housing as a live chassis so its not as simple as Chris’s second diagram shows. This live chassis bypasses one of those interupts usually the left motor brush is live to the wheels via the chassis. You have to find and isolate this path before you can fit a decoder. All explained by Brian as there are various types of ringfield.