Best all round DC controller

[ejstubbs]

1 hour ago, H2O said:

I agree that the input range needs to be above a certain minimum voltage for anything to work but I think the reference was to the controllable range of effective output voltage?

 

That was my understanding of the point that d00m seemed to be trying to make.  However, Barclay claims to have good results with the unit apparently branded "ZK-MG", and everywhere I've found that online it seems to be rated "5-30V".  If that is indeed the input voltage range then all fine and dandy - but then I don't really understand d00m's post (i.e. the one I quoted in my previous post).

[WIMorrison]

I would expect to see 2 voltages quoted, and input and output - otherwise you are just guessing 

[d00m]

Barclay was asking if anyone had tried the pwm controllers that were cheaper than the one that he bought- I was simply giving first hand experience of the ones that I have. Out of the two types that I have, the one 'rated' 4.5 - 30v produces a really rough output that does not go down to zero (as H2O mentioned).

As I said at £2  a pop you can't really complain.

If anyone really wants a picture of the two types I will put them up on here.

Edited April 4, 2021 by d00m

[ejstubbs]

This online shop selling the "ZK-MG" controller does include a diagram showing "Input DC 5V-30V".

 

30 minutes ago, d00m said:

If anyone really wants a picture of the two types I will put them up on here.

 

I think it would be helpful, if only to know which type to avoid.

[Barclay]

Yes mine had the same spec. but I assumed that meant the input had to be 5-30V. In practice the output certainly doesn't start at 5V, it is perfectly smooth and linear. I'm still playing with the PWM frequency, which can be adjusted between 1 and 100 khz. The higher you set it the slower the top speed appears to be. default is 20 and I'm currently running at 30 quite happily. I have to say on most loco's the Pentroller still has the edge but it's close.

[d00m]

not loading

 

Edited April 5, 2021 by d00m

[d00m]

[Sophia NSE]

On 27/03/2021 at 16:32, Barclay said:

The DIY controller works very well. It has a soft start facility and is very pleasant to use, with the motors running nice and quietly. At about £6 + a tenner's worth of bits to make it user-friendly (box, DPDT reversing switch, cable and grommet) it's well worth while getting one to have a play with - all you need is a 12V DC input.

 

How did you hook up the reversing switch as this little box of tricks interests me greatly

[Barclay]

Hi @Sophia NSEit's a double pole double throw centre off switch, so it has 6 contacts. 

 

The output from the 'gadget' goes to 2 at the end. Then you need 2 small 'jumper wires' across to the 2 at the other end, but they need to cross over so the polarity at the other end is the opposite. The 2 contacts in the middle are your output wires to the layout.

 

Hope that makes sense - I can't draw things on here !

Edited April 22, 2021 by Barclay

[Sophia NSE]

1 hour ago, Barclay said:

Hi @Sophia NSEit's a double pole double throw centre off switch, so it has 6 contacts. 

 

The output from the 'gadget' goes to 2 at the end. Then you need 2 small 'jumper wires' across to the 2 at the other end, but they need to cross over so the polarity at the other end is the opposite. The 2 contacts in the middle are your output wires to the layout.

 

Hope that makes sense - I can't draw things on here !

I think it makes sense. I'll give it a go! Thanks for your help 

[cliff park]

Like this :-

 

 

[Barclay]

A picture is worth a thousand words !

[Sophia NSE]

On 22/04/2021 at 14:15, cliff park said:

Like this :-

 

 

I thought that was how it was supposed to look from the description, but this confirms it. Now I just need to get a box to contain it all in

[Barclay]

16 hours ago, Sophia NSE said:

I thought that was how it was supposed to look from the description, but this confirms it. Now I just need to get a box to contain it all in

Got my bits from Cricklewood Electronics, but other suppliers are available !

[Sophia NSE]

Should have everything I need to make this controller. Hopefully the effects of the vaccine wear off before it all arrives 

[mikesndbs]

On 24/02/2021 at 23:26, 31466 said:

Hi everyone, been looking through these forums for a while but this is my first post. I have quite a few different questions so will write it out best I can!

 

I have a fairly large layout with 4 different tracks and would like to know thoughts on the best controller. I have had layouts for over 20 years so have used a fair few but I have concerns about my current setup.

 

Over that 20 year period I have had a Gaugemaster series DF controller. This has been faultless the whole time and it still powers 2 of the tracks. However I felt that it wasn't the most powerful controller. Many older models, Wrenn, Triang and some Lima etc were quite sluggish and having trialled a different controller I realised they had more speed in them. I was given an old Hornby 900 power control controller and this was very powerful and many models seemed much better. The only drawback was it is very bulky to control one track and it had a bit of a fault with the dial. I then decided to get a Hornby HM2000 controller. It seemed OK but the one I bought wasn't perfect and it had some strange characteristics so I bought another one brand new. It has the same curiosities! Having read other topics it seems that is how they operate with a "dead zone" for much of the dial and then the last little bit, dots 13 to 14 the models speed up like mad! I can live with that but I have had multiple loco failures using the controller and I am worried the controller has caused them. The failures are as follows:

 

Hornby Terrier - Smoke coming from motor, burnt out, dead

Hornby County - Smoke coming from motor, took apart and back together and runs OK, no sign of damage

Dapol Western - Loco stopped, bit of smoke, totally dead including lights

Hornby J15 - Loco stopped, completely dead

Hornby class 71 - Lights suddenly went out, works fine but no lights

 

They all seem fairly similar faults and could be caused by too much power going to the motor? I believe the Terrier, County and 71 all failed when the controller was on full power.

 

The HM2000 shows the voltage to track being 0-17V, this seems very high so if 17V is going to the track when on full power are failures pretty likely? Obviously I could regulate the power and stay off full but I would rather have a controller which I can use properly without worrying. I find it hard to believe that a current Hornby controller should throw out too much power for a current Hornby model.

My Gaugemaster DF shows 0-12V but also max 9.6VA to each track. I am not an expert with electrics but does that mean it doesn't deliver 12V to the track? I have looked at a Model Q 4 track controller and that shows max 12VA to each track so sounds better.

 

So I am looking at what my options are. I want a controller that isn't going to damage any more models but is also powerful enough so older models run at a decent speed. I am a big fan of the Gaugemaster controller, the dial changes the speed throughout the range unlike the HM2000 where most of the turn makes no difference. The model Q or 2 track equivalent is what I'm thinking, is this more powerful than my current series DF one? This also adds the question of feedback controllers (which I believe is what the series DF is). I don't know what difference they make but don't really want a controller that isn't suitable for certain models. My series DF has never damaged any models.

 

Just one last point. I have a DJ models class 71. On the Gaugemaster DF it is pretty slow. On the HM2000 it is even slower. Bizarrely I have a Hornby R965 small controller and it is pretty nippy on there! I have found the R965 is pretty powerful but it lacked the finesse I wanted for a main controller but the power it provides is great. I don't know though if they could damage models too. I have a number so could use those but just interested to hear any views.

 

I have all sorts of models from Hornby Dublo, Wrenn, Triang, Lima, Mainline, Dapol, Bachmann, Hornby etc and continue to buy the current models so some very different mechanisms and technology but it has all been newer models on newer controllers that have been the problem.

 

Sorry for the long message. There are loads of questions in there but if you have any views on just one I would be interested to hear.

 

Many thanks

 

Steven.   

 

Hi, I feel your motor failures will be as a direct result of the HM2000.

This uses PWM and a small amount of feedback that will on long runs overheat the motors and cause issues.

It can also fry electronic components.

 

The very best option for you would be a Morley 4 track control crawler, really flexible with hand held units and point CDU built in.

The crawler option means you can run locos at a crawl.

 

Of course there is the Gaugemaster versions, higher cost but backed by a lifetime warranty.

 

None of these controllers will harm your motors or any of the components within the locos.

 

You may find this helpful 

 

 

The DJ 71 is sadly only capable of around a scale 60 MPH due to the tiny, tiny coreless motor and high gears.

 

 

 

 

 

 

 

 

[31466]

On 10/05/2021 at 20:09, mikesndbs said:

 

Hi, I feel your motor failures will be as a direct result of the HM2000.

This uses PWM and a small amount of feedback that will on long runs overheat the motors and cause issues.

It can also fry electronic components.

 

The very best option for you would be a Morley 4 track control crawler, really flexible with hand held units and point CDU built in.

The crawler option means you can run locos at a crawl.

 

Of course there is the Gaugemaster versions, higher cost but backed by a lifetime warranty.

 

None of these controllers will harm your motors or any of the components within the locos.

 

You may find this helpful 

 

 

The DJ 71 is sadly only capable of around a scale 60 MPH due to the tiny, tiny coreless motor and high gears.

 

 

 

 

 

 

 

 

Many thanks for your reply. Thanks for the warning about the HM2000, I had my suspicions about it and you have provided some science as to why. It has been taken off my main running circuit and put on a lesser used track and I've had no failures since. Very surprised that a controller that can damage motors has been available for so long and still is!

 

Yeah the DJ 71 is sluggish isn't it! Hornby one much better which makes the light failure using the HM2000 even more annoying but could have been worse!

 

The video clip and suggestions are much appreciated.

[mikesndbs]

9 hours ago, 31466 said:

Many thanks for your reply. Thanks for the warning about the HM2000, I had my suspicions about it and you have provided some science as to why. It has been taken off my main running circuit and put on a lesser used track and I've had no failures since. Very surprised that a controller that can damage motors has been available for so long and still is!

 

Yeah the DJ 71 is sluggish isn't it! Hornby one much better which makes the light failure using the HM2000 even more annoying but could have been worse!

 

The video clip and suggestions are much appreciated.

 

Glad it helped, I think it's the case that models and motors have changed since the HM2000 was designed. If you stuck with older stuff there would 'probably' be no issues at all.

Let us know if you decided to get a Morley or Gaugemaster. 

[ejstubbs]

On 05/04/2021 at 09:19, Barclay said:

Yes mine had the same spec. but I assumed that meant the input had to be 5-30V. In practice the output certainly doesn't start at 5V, it is perfectly smooth and linear. I'm still playing with the PWM frequency, which can be adjusted between 1 and 100 khz. The higher you set it the slower the top speed appears to be. default is 20 and I'm currently running at 30 quite happily. I have to say on most loco's the Pentroller still has the edge but it's close.

 

I've just done some experiments with the "ZK-MG" controller and I have to say I'm impressed.  Very smooth running and the low speed control is much better than my Morley - even with the modification suggested by mikesndbs.  I like the gentle power take-up, though whether it might turn out to be an inconvenience when shunting I have yet to investigate in detail.

 

I'm currently running it off a 12V 2A DC wall wart (the kind sold for powering CCTV cameras and the like) which means that the maximum output voltage is ~12V, rather than the 15-16V that a 'straight' DC controller like the Morley delivers at full chat.  TBH I quite liked it on my BLT, where realistically you're never going to need full 'line speed'.  If I do decide I need more oomph I can just upgrade the DC power supply.

 

In my brief experiments with it "out of the box" I felt that I got the best results in terms of smooth running and controllability between about 5kHz and 10kHz.  The pulse waveform is a bit ragged (I may try and post a screenshot) but it seems to do the job in terms of controllability.  I wouldn't say it was completely linear: according to my cheapo 'scope the PWM pulses are lower than 12V at low duty cycle percentages so maybe it would be best to set the lowest duty cycle value to the lowest point where it actually delivers 12V pulses.  Some more experimentation needed there, perhaps.  AIUI the 'default' PWM frequency used in DCC decoders is 16kHz so maybe I'll try that.  (I don't know what frequency the Gaugemaster feedback controllers use; if I did I'd try that, too.)  I believe that higher PWM frequencies would be expected to reduce top speeds - something to do with the current not having time to rise to the maximum possible (the motor windings basically acting like an inductor) is how I've seen it explained.

 

For around a fiver, plus a box and a few other components (I already have DPDT switches kicking around in my bits box), it seems a total bargain compared to most brand name model railway DC controllers.  So what are the downsides?  It doesn't have feedback, which is noticeable when crawling, either through pointwork or transitioning from straight to curved track.  Personally I can live with that for now.  It might not be healthy for coreless motors, but that wouldn't currently be an issue for me AFAIK (my most recent locomotives are the Bachmann 0-6-2T and 2-4-2T which I believe have normal can motors).  The locos I tested it with did seem to run hotter than on plain DC; I understand that this is to be expected when using PWM but I'll keep an eye on it anyway.

[mikesndbs]

6 hours ago, ejstubbs said:

 

I've just done some experiments with the "ZK-MG" controller and I have to say I'm impressed.  Very smooth running and the low speed control is much better than my Morley - even with the modification suggested by mikesndbs.  I like the gentle power take-up, though whether it might turn out to be an inconvenience when shunting I have yet to investigate in detail.

 

 

 

Do you have a link to this please?

[Dungrange]

4 minutes ago, mikesndbs said:

Do you have a link to this please?

 

Link was further up the thread.

 

On 05/04/2021 at 00:50, ejstubbs said:

This online shop selling the "ZK-MG" controller does include a diagram showing "Input DC 5V-30V".

 

[mikesndbs]

OK thanks, interesting you can vary the frequency.

Only way to partly protect more sensitive motors is to reduce the voltage input.

Are you able to try 7VDC and see how it does?

[AndyID]

19 minutes ago, mikesndbs said:

OK thanks, interesting you can vary the frequency.

Only way to partly protect more sensitive motors is to reduce the voltage input.

Are you able to try 7VDC and see how it does?

 

Just a note:

 

Coreless motors tend to overheat on PWM because the rotor has much less mass than a conventional motor with a rotating iron core. A rotating iron core acts as a flywheel which keeps the rotor turning even when the input current is cut.

 

A coreless motor will slow down to some extent when the current is cut and have to accelerate when it is restored. The continuous deceleration and acceleration is what causes the heating.

 

I've never tried it but I think a small flywheel on a coreless motor should solve the heating problem.

[Sophia NSE]

Put mine together today and realised I didn't have a suitable power source so I tested it with a 9v battery to make sure my wiring was correct. It was, so a power source has been ordered

 

I know the wiring is a mess, but once the back is on the box it won't be seen. The box itself is small enough to fit in my hand

[Tony270145]

Thanks for the reply , but i did not want a lecture in wiring , i am starting from scratch with the wiring i have stripped out all my DCC Bus  wires, and the reason i have decided to go to a simple DC layout is that i am 76 with poor health , i just want a simple DC Layout where i can run my few locos , i was asking for advice on good DC Controllers thats all not to be questioned on my motives.

Tony