How to Build a Power Controller for Your Model Railroad

[@w.rustylane5650]

A very good idea for a controller. I will be making one of these using my wife's old Dell computer power supply. You have the very best of ideas I have ever seen. I have watched this video numerous times. I found a PWM power controller from China for $1.59. Kudos, Dave! :-)

[@stevenspaziani9159]

Hello again Dave. I bought a PWM motor controller and built a hand held controller from an old MRC one, the unit fit perfectly and worked flawlessly, slow speed is awesome, actually the best I've ever seen on my RR. I'm so happy I ordered a few more to build more walk around controllers. Thanks for the info.

[@DaveBodnar]

That is great to hear. Thanks!

[@04fys513]

I’m glad you mentioned MP Jones, Inc. I used to use them for motor controls and spare parts, but forgot all about them. They usually have great prices and good service. Them and Mouser.

[@74zelo]

Could you give us more specific info about the potentiometer. Where did you by it. How can we get one?

[@DaveBodnar]

Terry - the potentiometer that is shown in the video came with the speed controller - most such pots are between 10K and 100K - in some cases the value isn't that critical as they are acting as a voltage divider. You may find more information on my web page here: trainelectronics.com/PowerController/ dave

[@markloyd5082]

Where has this guy been? Thanks for all the great info!

[@HarryBHouchins]

Have you ever considered adding momentum to the throttle? I'd be curious how it can be done.

[@robc2536]

This is great information! Thanks Dave

[@WilliamBlyth-v6b]

Hi Dave! Great video... Following you for years. Have G, O, HO, N, Z and now... "T" gauge. Not quiet sure about the "T" gauge use.. but it's an interesting micro model. Your Voltage and Amps are right on the money. In fact, with the proper ratings, this solution works for Z, TT, and "T" gauge. Again, follow the power ratings for the engine being used. I did find Marklin Z has a slightly lower power rating as compared to other Z gauge models. Keep up the great work.! Love the Incline. takes me back to my ole' Pittsburgh days. From Philipsburg PA (formerly resident of Ohara Township.. ) Bill

[@AndrewBaka]

Dave, I bought DC Motor Control 32678-MD from Marlin R Jones and before permanently installing it on my n gauge layout I tested it and although it seems to work, it is causing my diesels to howl! I am powering the DC Motor controller by using the fixed DC terminal on my Tech II power pack which puts out 17 VDC. I tried running the diesels directly off the Fixed DC Terminal and no howling? Is there a way to decrease the howling that appears caused by the DC Motor Control?

[@DaveBodnar]

It is possible that the DC coming from the Tech II is not well filtered - to see if that is the issue try powering the power controller with batteries or from a well filtered DC power supply dave

[@AndrewBaka]

@@DaveBodnar Thanks Dave, I tried using batteries and the diesels are still whining. Previously I used a handheld controller that I built in 1993 from directions in a hobby mag. It had two transistors and I connected it to the fixed DC terminals of the power pack just like I with the DC Motor Control but I never had any trouble with the previous one? The only problem I ever had was with the connection to the railroad. I was using telephone mod line (28awg) and the wire was always breaking at the solder joint where it attached to the wire (20awg) coming out of the handheld controller. Do you think that continued use of the DC Motor Control will harm my diesel engines? Except for the whining the DC Motor Control seems to provide more power then my previous handheld controller.

[@DaveBodnar]

I don't think the wire is the issue - some motors don't like PWM - you could try building the add-on circuit discussed here: www.trainelectronics.com/PowerController/ the part you need is titled PWM to Linear Output and is near the bottom dave

[@Beatlefan67]

Proper work-bench there, Dave!

[@DaveBodnar]

It serves me well!

[@stevenspaziani9159]

Hi Dave, thanks for making an informative video. I've been trying to build a high power hand held throttle because nothing on the market is up to the task. I run big trains with mostly all powered engines and the hand helds breakers keep tripping and it's a real pain.. MRC hand helds are only good for maybe 1/2 amp and has become a real pain. I use strictly plain old DC because I have so many old locos and it's not feasible to go DCC. I have built them using rheostats in the past, but you need a big one and usually a big bulky box. I never heard of PWM motor controllers till your video and decided to try one out, thank God for Amazon as no one within 100 miles of my house sells anything like that. I ordered a couple that work up to 24 volts and 15 amps, ( not that I use that much power to run a train ) but it's nice to know the reseve is there. Eventually I want to run my whole RR off one power supply for ease of wiring and not having a bunch of transformers to worry about wiring together. I do have a sizable power supply that would power 10 model railroads (lol) but sadly it doesn't put out quite enough voltage about 15 or 16 tops so I figure I need about 2 more volts or so to get my trains up to speed. I'll let you know how they work out, I'm hoping the PWMs fit in an MRC hand held box.

[@DaveBodnar]

Steven - it is good to hear that you enjoyed the video. Have fun building the power controller and make sure you provide enough ventilation or a fan to keep things cool Enjoy dave

[@elpunto231]

Oh i could watch your videos all day...very nice!!!!

[@dukesnyder3607]

Many thanks!! You're very inspirational to us DIY folks!

[@jeffjovanovich5751]

Thank you for your knowledge. Mine works great.

[@DaveBodnar]

That is good to hear. Thanks for letting us know

[@mrk1075]

Is the dryer running in the background?

[@pipafumador]

Muchas gracias Dave. Una consulta, el potenciómetro también debe tener 20 Voltios y 3 amperios, igual que el transformador? Saludos desde Chile 🇨🇱, Sudamérica.

[@DaveBodnar]

The potentiometer is just setting the speed controller and does not carry any current. A simple trim pot should work

[@laurensiemens1436]

if you have a reverse loop on your train layout should you have your layout reverse loop connected with a dpdt switch on the controller or should you have the switch on a control panel mounted to your layout

[@DaveBodnar]

Lauren - Ideally you would have it operate automatically - There is an article on my web page that explains this in detail - see: www.trainelectronics.com/Reverse_loop_dual_coil_relay/ I hope that helps dave

[@dangoneau]

Finally a new upload! Always look forward to them

[@mountainsprings3303]

Great video and very well explained. Thanks

[@DaveBodnar]

You are quite welcome, Steven!

[@matt478911]

Hi Dave, I’m new to the idea of moving beyond the starter pack power supplies and very much a newbie when it comes to the idea of wiring up my own devices. I have 2 questions: should we be concerned with VA specifications? Also, I’m running Aristocraft locos that I’ve recently purchased on eBay and each ART product preaches pulse width control is to be used with their products. Would a pulse width modulator be comparable to PWC?

[@DaveBodnar]

Matt - I would look for a power supply that is rated at 2 or more amps at 18 or 19 volts - most (or all) Aristo Craft locos will work well with this type of speed controller as PWC and PWM are the same thing. Good luck with your project! dave

[@thedoctor6610]

Thank you for making this video I am in the UK . I have want to build my own Controller because of the price not lot to them . I know the mains here is 240 v But you is Still help me to build my own controllers I have book mk your wed sit

[@stevelhamon2031]

What amp of controller did you use?

[@DaveBodnar]

I believe they are rated at about 10 amps but I never used that much. The article here trainelectronics.com/PowerController/ discusses this and using an appropriate fuse. Dave

[@stevelhamon2031]

Well I bought a controller like the one you used. And it’s putting out the full 20v no matter where the knob is . Any advice?

[@DaveBodnar]

@Steve Lhamon sounds like the power transistor is shorted

[@stevelhamon2031]

Dave Bodnar it’s brand new?

[@DaveBodnar]

@@stevelhamon2031 Sorry to say but I have seen many such items DOA -

[@ModelRailwaysUnlimited]

Hi from the UK. Our trains run on 12 volts DC, I assume the bigger scale models you have are 20 volt machines? Do you select any particular frequency for your PWM controllers?

[@DaveBodnar]

The G-scale trains take up to 24 volts but work well at 19 or so. I haven't had any issues with the frequency of the controllers I have used - no buzzing or vibration - the PWM to Linear circuit on my web page would take care of any such noise dave

[@MFersOutdoors]

I'm new to all this and very interested in learning all i can . Is it possible to just use a light dimmer switch out of the power supply

[@DaveBodnar]

I don't believe so as they control AC and we are working here with DC motors dave

[@Totogita]

Very nice video! Do you get into solar powered emergency generators? If you do I will be on the first row watching.

[@DaveBodnar]

Dart - sorry, no solar powered devices on the horizon! dave

[@Lionmaster2808]

does this work with o gauge lionel locomotives

[@DaveBodnar]

No it does not Only for DC powered locks Dave

[@mariebcfhs9491]

Sir, I really appreciate you video, very detail guide, even electric noobs can follow quite easily. Great job Sir. I have one little question however: Can I use what ever DC dimmer I can get (the ones that are labeled suitable for motor control, of course)? Also which one works better between PWM dimmers and voltage regulating dimmers? What kind of dimmer that you used, may I know the specific type? Thank you very much Sir!

[@DaveBodnar]

It is good to hear that you have enjoyed the videos. Any DC speed or motor controller should work. The ones I have used all use PWM to vary the speed Dave

[@mariebcfhs9491]

@@DaveBodnar Thank you Sir, I also found out that the box designer is very useful!

[@Phillyrail]

Hi Dave, I read the article you wrote on how to build the controller and have two questions: is there a specific desirable reason to using pwm to drive the motor? Could you implement this system using just a potentiometer as one of the resistors in a voltage divider?

[@fluteplayerify]

You could, but using a voltage divider would be very inefficient (they release V*I of power as heat and you would need to pass enough current to run the motor). Finding a potentiometer rated to allow enough current to run a motor would be difficult and it would likely be more expensive than the PWM controller.

[@DaveBodnar]

PWM is the most efficient way to vary the power going to a motor - a potentiometer could be used but it would get very hot and would need to be quite large. dave

[@christopherletourneau8727]

I can not find the ART57091 to Get my PWM to Linear Is this something that can be bought elsewhere?

[@DaveBodnar]

They are no longer available but you can follow the directions at the bottom of this page to make your own - have fun! trainelectronics.com/PowerController/ dave

[@christopherletourneau8727]

@@DaveBodnar do you have a parts list and will this work with 20 amp?

[@DaveBodnar]

@@christopherletourneau8727 All I have is what is on the web page - the parts are identified on the schematic

[@laurensiemens1436]

thanks for the video I learnt something new today

[@reganmdonovan]

Hi, can this be done for DCC, in sync with say an arduino?

[@DaveBodnar]

This project is not meant to be capable of complex control - if you are interested in DCC have a look at DCC++, here www.trainboard.com/highball/index.php?forums/dcc.177/ and on my web page, here www.google.com/search?q=dcc%2B%2B&sitesearch=trainelectronics.com dave

[@achgreentree]

if one wants something other than a switcher supply a simple emitter follower circuit works vary smoothly

[@romansyah8651]

hello sir, I really like your arduino diy programmer. Can you make a tutorial on basic microcontroller PWM analog DC motors with engine sound for miniature trains. thanks for your idea. 🙏

[@MrLosttheplot]

great video, thank you.

[@timcoe6841]

Great videos Dave. I may be able to adapt some of your ideas to my tinplate Flyer layout. Thanks. BTW, I've subscribed.

[@DaveBodnar]

Good to hear that you liked the project. Good luck with yours!

[@ICStation2013]

Awesome video!

[@coloursmoke]

** Thank you Sir! Very useful video and webpage. ** :-)

[@Mikeywil0003]

I recently had to find a 24 volt power supply, and I was very surprised to see how little options there are. I was wondering if those open frame 24 volt supplies are built well. I have a Korean computer monitor that has a surplus 2560x1440 Apple Cinema Display panel in it that runs off 24 volts, and draws like 5 amps. It is supposed to use a laptop style power supply, but the original one burned up. They get very hot in operation, have zero ventilation, and have very poor quality components in them. They are also plastic welded together so it can't be opened to replace the poor quality components with better ones. I assumed that the open frame supplies would be a similar inferior design. Even the replacement I got for it is a poorly made unit. Are the open frame supplies from MPJA actually a good design? Or are they just reselling Chinese made supplies?

[@DaveBodnar]

The MPJA power supplies are surely designed & made in China but the ones I have used and that our Garden Railway Club uses have worked very well for a number of years. At the price they are worth a try. dave

[@Mikeywil0003]

Dave Bodnar wow, I didn't expect such a quick response. Have you had the cover off of any of them? Some of these Chinese supplies actually scare me because of how poorly they are made. I know practically everything is made in China these days.

[@DaveBodnar]

I just took the top off of one of the power supplies and posted a photo here www.trainelectronics.com/temp/ps-jpja.jpg The components are not wonderful but it looks to be well made. dave

[@Mikeywil0003]

Dave Bodnar thank you very much Dave. That answers all of my questions about those supplies. It does look to be a decent design, and looks like it would be easy to repair if it ever let the magic smoke out. I went as far as blowing up pictures of them to try to see through the perforated top, but couldn't see much. I think that since my device draws 5 amps, I'm going to look for a 7.5 amp or 10 amp supply, just so it isn't running right on the edge of its current limit. I think that a power supply running at 50% all the time would hold up a lot better than one running 100%.

[@grisall]

great video -- thanks

[@lazyrrr2411]

Now we're talking ! 👍

[@benztrainz9030]

just use a lamp dimmer to control the ac input to the transformer...

[@f.glenskidmore1678]

To eliminate the wasted heat from large amperage throttles like G sale uses, why do we not use variable transformers like Lionel made in 1950, and just rectify and filter the variable AC current to DC for DC motors? That would be super efficient for power usage with the slower speeds not creating any heat. I understand cheap power packs for trainsets, but a variable voltage AC transformer is never even considered. A small variable voltage transformer should be viable and safe if designed correctly.

[@DaveBodnar]

good question, Glen - not sure but it sounds like it could be done - most likely a cost issue dave

[@Ashton351]

Why PWM? Why not just a pot?

[@DaveBodnar]

Pots were used for years but to control several amps at 15 or 20 volts would take a really high wattage pot that would get quite hot. PWM is more efficient and less costly. dave

[@daveday5507]

That's not a power controller, it's a speed controller. Yes, I'm pedantic.