Modern Wireless DC control

[Point353]

It's a very cool technology, but I don't think it fits the "needs to be as stupid simple as possible" need. In this build, I'm looking for something so simple that someone can understand how it works just by looking at it.

Would the "user interface" for the following device meet that requirement?

http://www.bluerailways.co.uk/Images/Model720-Shop.png

[mmagliaro]

Would the "user interface" for the following device meet that requirement?

http://www.bluerailways.co.uk/Images/Model720-Shop.png

Heh... mighty familiar idea.   

[timwatson]

Hey @Ed Kapuscinski have you seen any of these options?
I only ask because the top one Dave Meek used on one of his layouts and said it performed well. Then I just expanded my search on PWM dc motor control.
If anyone has used any of these I’d love to hear how it went?

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[Ed Kapuscinski]

Interesting. I have NOT tried any of those, but am definitely curious!

[timwatson]

The middle one has my attention. I wonder if @mmagliaro has tried any of these? These are not wireless however. So mileage may vary.

[Point353]

Interesting. I have NOT tried any of those, but am definitely curious!

Do you no longer need the wireless functionality?

[mmagliaro]

The middle one has my attention. I wonder if @mmagliaro has tried any of these? These are not wireless however. So mileage may vary.

I have not.  I bought a PWM module off eBay 5 (?) or so years ago, and it worked fine.  It was only designed to output a few hundred milliamps.  I bought it because I was curious about how well it would control a loco.  It did fine.  Frequency was 16 kHz.  No motor noise, good low-end startup, like you would hope.  And the frequency was honest (checked it on a scope).

I forget now if I brought this up, but Ed, if you run any decoder-equipped engines on your DC trackage with these things, a PWM controller might cause a lot problems.  I know that isn't your "plan", but if you think it's a realistic possibility, test whatever controller you settle on with some DCC engines, just so you know what will happen.

[timwatson]

Interesting DCC decoders I hadn’t considered, is that a known thing? Off to the internet I go.

[peteski]

Interesting DCC decoders I hadn’t considered, is that a known thing? Off to the internet I go.

The DCC control packets the decoder receives and acts upon are encoded in the pulsing DCC track voltage. The PWM DC throttles pulses can sometimes confuse a decoder that it is a DCC signal, making it behave erratically.  It is not a widespread problem because the erratic behavior will depend on how good or bad a certain brand decoder is in rejecting the PWM pulses, and also on the frequency of the PWM pulses produced by a specific throttle.  Plus, not many people who own decoder-equipped models actually run them on DC layouts (end even less often on DC layouts using a PWM throttle not an old-fashion variable DC voltage analog throttle).

[timwatson]

Thanks @peteski ! Makes sense in hindsight.

[mmagliaro]

Update time: I've have had some success and am looking forward to more.

I got two 14v to 12V converters along with a second controller. They're being fed from the laptop power supply that Max found me.
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Ed, something I just thought about with those laptop power supplies... if you ever have a short, those things will automatically shut themselves down, which is not a bad thing.  BUT, a lot of them (if not all of them), will just wait a couple of seconds and then power back up again.  They will cycle on and off like that forever until you clear the short.  This might be no big deal, but it might be a real pain if you have an engine derail, short, trip the power supply, then it powers back up, more sparks, shut down, over and over again.  I would expect that whoever is running would turn down the throttle by that point, but that might not be so easy if the throttle's power supply is constantly shutting down every couple of seconds.   If those those things you are using automatically power back up in the "off" state, then this won't be a problem.

[Ed Kapuscinski]

Ed, something I just thought about with those laptop power supplies... if you ever have a short, those things will automatically shut themselves down, which is not a bad thing.  BUT, a lot of them (if not all of them), will just wait a couple of seconds and then power back up again.  They will cycle on and off like that forever until you clear the short.  This might be no big deal, but it might be a real pain if you have an engine derail, short, trip the power supply, then it powers back up, more sparks, shut down, over and over again.  I would expect that whoever is running would turn down the throttle by that point, but that might not be so easy if the throttle's power supply is constantly shutting down every couple of seconds.   If those those things you are using automatically power back up in the "off" state, then this won't be a problem.

A good point. I spent some time playing with it all. What I discovered is that the 14=>12v converters are also circuit breakers, so we're covered there.

I discovered this when I was using them to step voltage down to the other throttles and they'd trip before the onboard short protection there did. 

So I think we're covered.

[mmagliaro]

Ed, so when you have a short, those things with the breakers actually "trip" and stay off?  And they trip faster than the
overload protection in the laptop power brick does?   If that's true, then yep, you're going to be okay.

[Ed Kapuscinski]

Ed, so when you have a short, those things with the breakers actually "trip" and stay off?  And they trip faster than the
overload protection in the laptop power brick does?   If that's true, then yep, you're going to be okay.

Yep! They stay off until it's cleared. I was pleasantly surprised.