Author Topic: Rapido SW1200RS  (Read 386 times)

CPRail

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Rapido SW1200RS
« on: October 03, 2018, 07:27:05 PM »
Hi List,

I cracked open my Rapido SW1200RS (it was easy - not sure why everyone says its a bear). There is room for a LM in there, as long as you move the speaker. Luckily it appears that the speaker will fit where Rapido has a small additional weight, if you cut down the speaker housing a bit.

There is one hindrance. There are two 'buttons' (for lack of the correct word) on the Rapido board labelled 100 with what appears to be copper wire wound around them. Of course, they are right in the middle of where the LM would sit nicely.

I have no idea what they are, or what they are for. I'm hoping that the electrical gurus can identify them and advise. HELP!!

Picture attached of the 'buttons'. More pictures of the guts as I get a chance to upload them.
Ian Lisakowski
Modelling CP Rail & VIA in the early 80's
Rabid Winnipeg Jets Fan - Go Jets Go!!

Excuse me, I believe you have my stapler...
M. Waddams

Alan

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Re: Rapido SW1200RS
« Reply #1 on: October 03, 2018, 07:35:53 PM »
They are inductors (coils / chokes). They need to be taken out and replaced with a jumper during LM installation. Refer to this thread: https://rpug.pdc.ca/index.php/topic,295.msg2101.html#msg2101
Alan

LK&O Railroad website

When I was a kid... no wait, I still do that. HO, 28x32, double deck, 1969, RailPro

CPRail

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Re: Rapido SW1200RS
« Reply #2 on: October 04, 2018, 01:04:59 PM »
Thanks Alan. I knew someone would know what they are. I read the recommended thread, but I didn't see anything about installing a jumper. Am I just jumping between the two locations across the board or?

To me electronics are mysterious smoke filled things (I believe we proved that electronics are smoke powered a while ago <wink wink>), so I need your steady hand on the tiller as I navigate this wee beastie.

I just love being the pioneer on installs...
Ian Lisakowski
Modelling CP Rail & VIA in the early 80's
Rabid Winnipeg Jets Fan - Go Jets Go!!

Excuse me, I believe you have my stapler...
M. Waddams

Alan

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Re: Rapido SW1200RS
« Reply #3 on: October 04, 2018, 02:48:14 PM »
Unsolder the inductor. Remove it from the board. Solder a wire across the two holes. Repeat for the second. You are replacing each inductor with a piece of wire.

You may want to try the installation with the inductors in place. Tim reported the LM doesn't play well with them but your inductors may not be the same value as were his. You may get different results. We sort of determined that RP uses a higher frequency PWM than does DCC hence why the inductors work with DCC and not RP. Series inductors block high frequencies. They are low-pass filters i.e. they only allow signals below a certain frequency (determined by the inductor value) to pass through. They also help prevent the circuit from becoming an antenna that would mess with radios and the like. We suspect this is the reason they are included.
Alan

LK&O Railroad website

When I was a kid... no wait, I still do that. HO, 28x32, double deck, 1969, RailPro

CPRail

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Re: Rapido SW1200RS
« Reply #4 on: December 14, 2018, 06:54:01 PM »
Continuing my descent into madness by working on tight switcher installs, I finally got time to work on this unit. The inductors are successfully removed and jumped, the speaker has been trimmed to fit and now I am in the getting it all to fit under the hood stage.

As you can see on the attached photo, the LM-3S protrudes above the light assembly for the front of this unit. If you recall, SW1200s have angled top hoods the length of the unit. The light assembly shows what I need to adjust on the LM-3S. This is the 6 pin end, but the adjustment needs to be the length of the module.

Before I start hacking away at the module to angle the sides, what's under the hood of a LM-3S? Should I unwrap the module and hack away, or would it be wiser to toss the board and hard wire in the module.

Before you say toss the board, be advised that these Rapido units are FULL of lighting. Cab interior, number boards, class lights, headlights, ditch lights, truck lights, and I'm sure there is something I've forgotten. That board is crucial to getting all the lights to work. I haven't figured out all of them yet, but I do have the head lights and class lights working just off the 9 pin side so far.

Thoughts, comments, rude remarks from the Learned Experts of RPUG?

Ian Lisakowski
Modelling CP Rail & VIA in the early 80's
Rabid Winnipeg Jets Fan - Go Jets Go!!

Excuse me, I believe you have my stapler...
M. Waddams

Alan

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Re: Rapido SW1200RS
« Reply #5 on: December 14, 2018, 07:12:19 PM »
Looking at you image I have to say no way. The plastic wrapper around a LM is thin plastic with the innards tight against it for the most part. Minus wrapper you save maybe 0.060" total width/height. Looks like you need much more than a few thousandths.
Alan

LK&O Railroad website

When I was a kid... no wait, I still do that. HO, 28x32, double deck, 1969, RailPro

CPRail

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Re: Rapido SW1200RS
« Reply #6 on: December 15, 2018, 05:01:20 PM »
Nuts. I really was hoping to avoid tossing the board. More poking and pondering to come!

Stay tuned.
Ian Lisakowski
Modelling CP Rail & VIA in the early 80's
Rabid Winnipeg Jets Fan - Go Jets Go!!

Excuse me, I believe you have my stapler...
M. Waddams