New controller makes trains hum

[Danwa]

Recently got back into model trians and after a few hours my old R965 controllers died.

I brought a new R7229 controller to replace them. Using this it creates a very loud humming noise from the trains when the power is on any level and at about 2/5ths power they start to move slowly.

I have tried this controller with both p9000 and c912 transformers.

im guessing the contoller is defective but not looking forward to spending more money right now and returning anyhting is going to be difficult. 

does anyone have and advice on what else could be wrong?

[96RAF]

Ring up HCC and ask them about it. Number is at the bottom of every page.

[Chrissaf]

The R7229 requires a power supply unit that is 19 volts DC.

The C912 is totally unsuitable as its output is AC.

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Are your locomotives the same vintage (age) as your old R965 controller. These old locos require so much more current compared to modern locos to move. Thus having to turn up a low powered controller (the R7229 is a low powered controller) is to be expected.

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The R7229 being a new Hornby release controller may very well be using a technology termed PWM (Pulse Width Modulation). Again, PWM is more suited to modern locomotive motors. PWM if viewed on an Oscilloscope is a variable width pulse square wave voltage. A PWM square wave voltage is very likely to make an old loco motor hum whilst the motor is still stationary and not turning at an appreciable rate of revolution.

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If your locos are indeed old locos with old designed motors such as for example the Hornby X03 / X04 motors. Then they could probably do with being remagnetised by the likes of Scalespeed.co.uk. A more appropriate controller probably wouldn't go amiss either. I actually doubt that the R7229 is actually faulty, more likely just an inappropriate controller for the task you trying to get it to do.

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To see the effect of motor magnetism (lack of) on a motor performance. And why the services offered by Scalespeed can be so beneficial.  See this YouTube video.

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TIP: As a newbie poster on the forum, just be aware that the 'Blue Button with the White Arrow' is not a 'Reply to this post' button. If you want to reply to any of the posts, scroll down and write your reply in the reply text box at the bottom of the page and click the Green 'Reply' button.

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See also – further TIPs on how to get the best user experience from this forum.

https://www.hornby.com/uk-en/forum/tips-on-using-the-forum/

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[Danwa]

hi Chis

thanks for replying ive tried using the p9000 as well could i have a variant of this that is also outputting AC?

The trains i have are all around a decade old. (i think)

i have a hornby R150 and a Smokey joe, got around the same time.

and a bachman 170/4 32-452

They all make loud humming when started

do you know if thease are old enough to case problems with PWM? 

[Chrissaf]

Look at the label on the P9000. It should be very similar to this one. The P9000 is the Hornby recommended power supply for the R7229.

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The output is 19 volts DC at a max 0.5A.

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How can I tell that the output is DC and not AC. Because the label is adopting 'Industry Standard' labelling symbols. The horizontal line over the horizontal dotted line between the 19V and the 0.5A is the industry standard symbol for DC. Wheras the ~ symbol (wavy line) after the 240V is the Industry symbol for AC.

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If you look at the video that I gave a link for in my original reply, you will see that these old locos with lost magmatism can easily draw 600mA (0.6A) which is more than the low powered P9000 / R7229 can supply. Remember that the R7229 itself, will consume some of the power supply 0.5A current to function, leaving less than 0.5A (500mA) for the locos.

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[ColinB]

If you say the controller needs 19 volts DC (funny value) and you are supplying it from a transformer with no rectification that would probably explain it, perhaps the voltage to the track has an AC element to it, that would make them buzz. If they were Wrenns or really old Hornbys X04s, they could lose their magnatism, but not a reasonably new Bachmann. Find a 19 volt power supply if you can't, to test it,  you could use a car battery charger, if you can set it to trickle charge, not full charge, but only use it to test it. It appears some laptop chargers are 19v dc.

Sorry just looked at my dc controller, you cannot use a battery charger as you need the right plug on the end.

[Chrissaf]

If they are genuinely only a decade old, then they are not likely to be the older X.03 / X.04 motors. They might be 'Ringfields' or the more modern 'Can' motors.

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As I said before. The P9000 power supply [19 volts DC 0.5A] you have already been using is the Hornby recommended power supply for the R7229 controller. See yellow highlight on image taken from P9000 product page.

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Message for Colin,

One reason the R7229 uses 19 volts DC input is because it has an integral CDU built into it for operating DC Analogue points. The higher 19 volt DC input means that the CDU is more efficient when minimally sized capacitors are used to save weight, product size and cost.

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[Going Spare]

The R150 B12 was last made around 1978 and will therefore have an X04 motor plus, possibly, synchrosmoke so it will certainly be a heavy load for modern controllers.  Smokey Joe and I would have thought the Bachmann 170 should be within their capabilities. 

Interesting that Danwa linked the C912 transformer to the R7229 controller: I thought Hornby fitted different plugs to prevent AC being fed to a DC-input controller, but my memory may be at fault there.

[Flashbang]

The P9000 power supply is the only one that should be used with the R7229 train controller.

It almost certainly uses PWM pulsed track output, as it is the 'modern' way of undertaking smooth loco control.

Why Hornby have added a built in CDU is beyond my conception, as their only method of operating a solenoid point motor is via the Hornby R044 Black lever, which is not ideal for use with a CDU - Really Hornby? Or are we to see a new and improved R044 point lever released?

TBH there are far, far better train controllers available! 

[ColinB]

Well I did a google search R7229 and it looks like a basic controller, it appears to have a 14 volt uncontrolled DC output on the back. Now I don't know if Hornby use the same technology on all their controllers, but I took the one I got free with my Pendolina set and took it apart to see what was in it. The 19 volt DC input feeds a bridge rectifier made of SMD diodes, so obviously it doesn't need to be a DC input. This then generates a PWM of 55 Hz . Now I used this controller on my Hornby Fowler 4p made in the 1980's and yes first couple of goes it buzzed and tripped out, as it hasn't been used for 20 years, but once it had been up and down a couple of times it worked OK. The Bachmann definitely shouldn't buzz with this controller. I use this controller to test all my locos before I convert them to DCC.

I have just tried my really old Fowler 4p again (I did the previous test a week ago) and sure it buzzes when it starts to move, but I am sure it always did that but once it is moving any noise is drowned out by the motor.

I have a Smokey Joe I bought it the 80s/90s, just tried it, works perfectly, didn't even trip out the controller. The Smokey Joe I have has a can motor.

I agree with RAF96 return it to Hornby, I suspect something is wrong inside.

[Abeginner]

Well not really an answer to the original post, more of an observation really. I bought the Eurostar train set, by and from Hornby. Included were the P9000w and the R8250. The track is all new, and put together well. It is an oval extended by 3 three additional long sraights on third radius, with own power supply.

The train emits quite a hum when it first starts, but sounds quite authentic like an electric train.

I have not thought to try either of my other trains with the new controller etc. To see if they emit the same hum.

My biggest disappointment is my tender driven duchess of Sutherland, which has a light under the front of the locomotive. It works for a short time but then stops. I an afraid to take it apart as I am unsure how to test it anyway.

[ColinB]

@Abeginner I did that with my Duchess of Sutherland and the plastic light guide just disintegrated as I pulled it apart. I think the light is driven off the front bogie and it is a small bulb, so I suggest cleaing the front bogie wheels. I think all my trains make a buzzing sound when they start up with that controller, the pwm frequency Hornby use is quite low so perhaps that is the issue, trouble is when any motor starts up there is a buzzing sound as the motor brushes pass the current to the motor at slow speed. On my one I even added one of those Hornby 1980's smoke unit, it worked quite well although a bit messy. Because I could mount it to the chassis no issues with the body warping with the heat.

[Ruffnut Thorston]

The light on the Duchess of Sutherland is powered by a brass wiper bearing on the top of the front driving wheel, on the Right hand side, looking forward from the cab.

 

It slots into the cylinder block, where it makes contact with a brass piece, that makes contact with the bottom contact of the bulb.

 

The current return is through the chassis, and left hand driving wheels.

 

The bogie is not connected for pick up purposes.

 

Service Sheets...

 

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[Danwa]

Hi Everyone thank you all so much for spending your time trying to help, still not really sure what the problem is but maybe a replacement controller is worth a try now.

I have recorded one of my trains running on my old controller and the new one both with their respective transformers:

Old   C912/R965 - notice the slow speed control

New  P9000w/R7229 

Hopefully this will help explain what i'm experiencing better 

 

Also decided to do the same thing with my Bachmann :

Old

New

[Alwicon]

Also have that problem.  I bought the new train set the GWR one which comes with a new controller and when I turn it on the locomotive hums and buzzes until I have turned it up to over halfway.   I tried my old controller for ten years ago and plugged it into the track and the locomotive runs from the first turn with no noise.  Are these new controllera useless??

[Australian model rail road]

Just get hold of a old Hammant and Morgan controller if using DC it will give years of trouble free use or a gaugemaster which are better

[ColinB]

Be careful with old Hammant and Morgan ones if you have any locos with DCC compatible decoders fitted, the regulation on these old controllers is a bit suspect, means it can damage any electronics. They are OK with pure DC locos as the motor copes with the irregularities of the the output, it appears the electronics cannot. I permanently damaged a DCC decoder on my H & M, yes it was supposedly DC compatible. As to the huming, I tried out my brand new Hornby Princess Elizabeth this morning and yes it hums with the controller. I think the PWM frequency is too low, when I used to use DC I built my own PWM controller, I used a PWM with a frequency of 10 kHz which makes less noise. 

[AlanPW]

The humming noise, on slow speeds or starting, seems to be normal for the current basic controllers.

I have a couple of older controllers to negate this. Interestingly enough Youtuber Sams Trains did a comparison of controllers, see the link here:

 

If you skip forward to about the 10 minute mark you'll hear the humming.