DC Motor Speed Controller，6-28V 3A

What me in the DC Control section, am I lost

Well no, since moving over to O gauge, the only running loco's I have are small RTR 0-4-0 or 0-6-0 tanks, and fitting a decoder in was simple - just drop in a 4mm designed decoder and all was OK.

Now I've having a go at kit building I need to run in the motor & gearbox and determine the current draw of the loco before fitting a decoder (most 4mm decoders are designed for between 0.5 & 1.0 A steady consumtion with peaks upto approx 1.5A).
My old H&M Duette can provide a max of 2A before thermalling, and my NCE PowerCab is rated at 1.5A. I therefore needed a meatier DC controller to allow me to run the loco in, determine the current consumption (average and stall currents). I could have purchased a newer stand alone controller, but for just running in seemed a bit excessive. I did consider building a controller using a power transistor - real old school, and started looking for an example circuit and bits, then stumpled upon this from Amazon

DC Motor Speed Controller，6-28V 3A PWM DC Regulator Speed Electric Motor Controller with Switch Function

£6.39 and three days later this arrived

I already have a 12V 4A DC power supply - but plenty are available from the likes of Amazon or Ebay for around a tenner.

Connect the 12V supply to the + & - terminals, and the track to the remaining terminals and it's a runner.

I will be making a face plate which will include a voltmeter and ameter (cost was approx £3) plus a switch to choose between DC or DCC, so I'm looking at a full solution for approx a tenner (or £20 if you include the psu).

This is a PWM (pulse width modulation) based controller, so should give good slow running properties, we'll see, and I'll post up the progress.

Paul

 

Hi Gormo

PWM is better suited to cored motors than coreless, but as this is intended for running in loco's on the rolling road, I'll learn to put up with it or turn the music up louder

Just done the first draft of the face plate



Large aperture is for the LCD voltmeter / ameter, center hole is the direction switch, and the final hole is for the pot.

Forgot to mention, the pot has an off position when turned fully anti-clockwise, the direction rocker switch also has a center off.

I will print it up tomorrow and see how it looks.

Paul

 

Nuts - It won't fit on the build plate - definately time for bed

Paul

 

OK version 2 of the faceplate



Now this is pretty much full size of the build plate, the print has started, we'll see how it goes.

Paul

 

And the print is ready (I forgot to post the reply before taking my daughter back home )

Just need to let it cure then try the bits for fit.

I intend to spray the faceplate, not sure what colour - yet.

Paul

 

Assembled looks like

Modifications, I think I need to move the display unit in from the edge and reduce the verticle size of the display aperture, somewhere safe I have a different type display unit, which may be smaller as I would like a bit more panel around the edges to allow for the ham fisted oaf who will cut the aperture for it to fit in.

I have spunt the controller board through 180 degrees from the photo, but think I will make panel higher as well - currently 60mm high, I'll increase it to 66mm (max size is 68 - but the edge wouldn't be as well defined as can be seen in the length which is at the max 120).

Or I could split them up on to separate panels

Paul

 

Found it



Back to the drawing board

Paul

 

OK version 3

Toto had suggested that I made it thicker, so now 3 mm thick, the recesses remain 1 mm thick for the retaining clips.



Also added reinforcing strips



Now off to print it - back in an hour or two, SWMBO has a list to be done.

Paul

 

This time printed in Grey resin

General comment, the grey stinks more than the green resin.

Front view

and the rear view

assembled



Wiring diagram to follow

Paul

 

OK so I couldn't resist, I've made the case as well



The front fits into the recess, like wise the rear has ventilation slots with a recess to hold a fan if needed - I may need an additional hole for air intake , oh well we'll see, the print has started and is due to take 10 hours

Paul

 

view from the back



Paul

 

8h52m later (actually 14h as I was in bed)

And with front fitted

Sides will need a little sanding before paint

Wiring next

Paul

 

Well I'm quite chuffed with this, so I decided to splash out on some connectors, rather than have wires just popping out of the back.

For the power supply 5 x 2.5 mm connectors,



and for the track 5 x 2.1 mm connectors - I will use the screw sockets as above, but with terminal adapter plugs to the track so I can easily change polarity



Paul