Building a DC train controller.

[brian777999]

1. Could this power source and this PWM be combined to use as a train controller ? I would have a qualified person check it out before actually using it !

 

2. Could the reversing switch and supplied potentiometer on the PWM be replaced with a centre detent potentiometer (centre off like the H&M controllers) ?

 

https://www.ebay.com/itm/131384581126?ssPageName=STRK%3AMEBIDX%3AIT&fromMakeTrack=true

 

https://www.ebay.com.au/itm/DC-12-24-36-48V-60A-PWM-Motor-Speed-Controller-CW-CCW-Reversible-Switch/163328680990?_trkparms=aid%3D1110006%26algo%3DHOMESPLICE.SIM%26ao%3D1%26asc%3D20200818142525%26meid%3Dd9775af0ef2f4c05933cf9cf48f5d6f5%26pid%3D101195%26rk%3D3%26rkt%3D12%26mehot%3Dag%26sd%3D112713952838%26itm%3D163328680990%26pmt%3D1%26noa%3D0%26pg%3D2047675%26algv%3DSimplAMLv5PairwiseWebWithBBEV2bDemotion%26brand%3DUnbranded&_trksid=p2047675.c101195.m1851

Edited August 29, 2020 by brian777999

[kevinlms]

13 hours ago, brian777999 said:

1. Could this power source and this PWM be combined to use as a train controller ? I would have a qualified person check it out before actually using it !

 

2. Could the reversing switch and supplied potentiometer on the PWM be replaced with a centre detent potentiometer (centre off like the H&M controllers) ?

 

https://www.ebay.com/itm/131384581126?ssPageName=STRK%3AMEBIDX%3AIT&fromMakeTrack=true

 

https://www.ebay.com.au/itm/DC-12-24-36-48V-60A-PWM-Motor-Speed-Controller-CW-CCW-Reversible-Switch/163328680990?_trkparms=aid%3D1110006%26algo%3DHOMESPLICE.SIM%26ao%3D1%26asc%3D20200818142525%26meid%3Dd9775af0ef2f4c05933cf9cf48f5d6f5%26pid%3D101195%26rk%3D3%26rkt%3D12%26mehot%3Dag%26sd%3D112713952838%26itm%3D163328680990%26pmt%3D1%26noa%3D0%26pg%3D2047675%26algv%3DSimplAMLv5PairwiseWebWithBBEV2bDemotion%26brand%3DUnbranded&_trksid=p2047675.c101195.m1851

Is that PWM controller intended for your ride on train? Up to 48V & 60A, (although not both!) makes it quite a large controller.

 

No you can't just replace the pot, to give you centre off, with forward/reverse. A circuit redesign is required to give you a positive & negative supply.

 

 

Edited August 30, 2020 by kevinlms
spelling

[heavymetalwagons]

Look in 

May be of help 

[lesmond]

The 300 mA output from the power supply would put me off it - I'd be looking for at least 1 amp.

 

Les

 

 

[PatB]

For a power supply, I'd be looking at something like this. Just plug and play, with no need to muck about building a housing acceptable for mains equipment. I also checked and it appears that Jaycar have a branch in Cairns.

 

The PWM unit you show would (probably) work, but seems a bit OTT for model motors. One of these or these might be more sensible, although you'd need to put your own DPDT reversing switch in the output.

 

The other thing to consider is some sort of short circuit protection. Most ready made electronic units seem to be self limiting on output current, but given the 10-20A rating of the ones linked, I wouldn't rely on it for model use. Jaycar would also be able to sell you a mechanical thermal cutout of a suitable (1.5-2A) rating, or, more cheaply, a self-resetting thermal fuse (commonly referred to as a polyswitch) to perform the same function. Or you could go old school and put a 21W car indicator globe in series with the output, which will limit the short circuit current to 1.75A for a 12V unit.

[Penlan]

For the 21w bulb, I use these '12v 21w Bay9s Hy21w Miniature-Amber Indicator bulb'
their dia is small and thus can be used to project through the controller face panel.

[AndyID]

On 15/09/2020 at 08:55, JimRead said:

Hello all,

 

I do tend to go on a bit about DC controllers, I've made them since the late 70's.
I wish I'd come across this one first instead of about 5 years ago.

 

So simple it doesn't even need a circuit board.

 

Scroll down this page to see the circuit for the above, it's the second one down with two BC557's: https://www.scottpages.net/ReviewOfControllers.html

 

A Triang/Hornby 'Nellie' chassis with the original motor.

 

 

I stop it several times to demonstrate the ability to move a few millimetres and on the way back stop it to show the feedback.

 

Cheers

 

Jim,

The link to the circuit does not work for me. Is it a good old-fangled emitter follower?

Thx.

Andy