Hornby Select "Losing Control"

[BritInVanCA]

I have a Hornby Select with Firmware 1.6 and since I sent it in for the Firmware update it seems to be losing control of certain locos i.e. I set them running ok but then I cannot slow them down or stop them with hitting the "panic button". Some of the locos that have issues are using TCS chips but I know these conform to the standards so I don't think it should be a problem.

I saw a YouTuber comment they had the same problem with their Select so I was wondering if it is a known issue.

[RDS]

If this has happened since you sent your Select in for update, I suggest you contact Hornby to advise them what has happened and see if they can offer any further help. Having said that, I have the same update on my Select without any of the problems you describe, although I do not have that particular make of Decoder.

[Fishmanoz]

If I can ask a few questions before we get to warranty return:

• have you downloaded the v1.5 manual and 1.6 addendum and are you operating in accordance?
• which power supply are you using - 1 or 4 Amp?
• how many locos do you operate at the same time?
• does the loss of control occur when only the affected loco is on the track or only with a number operating?
• does it occur at any particular speed setting or whatever the setting?
• does it continue as per the last setting you made with it or does it take off flat out (DC runaway)?
• Does it lose control if you just leave it for a while or only after you’ve controlled another loco then come back to it?
• did you mean “with hitting the panic button” or without hitting it?

[P-Henny]

Just to be a double check. Make sure that your track power connections have had their suppression capacitors removed. Products that need this modification for DCC working are R602, R8206 & R8201. Whereas R8241 & R8242 are already DCC compliant. Some very early Digital Sets had the wrong power connector shipped in the set. The capacitor, if present, can cause the issues you have described. It is possible that your later Select firmware is only now showing these issues up.

The clamshell of the power clips can be prised apart to reveal the innards. The centre (between rails) cover on the power track can be prised off. Remove any component (capacitor) that is soldered across the rail connectors if present.

[96RAF]

TCS, Bachmann and some other decoders have long since been known to play up with Hornby controllers. American decoders in particular as they fail to meet European EMC requirements.

This from my file notes...

The ELITE (and the SELECT) meets EN55014 EMC Electro Magnetic Compatibility Directive certification i.e. when under load as specified by the requirement. To meet this requirement the output of the ELITE/SELECT is “tuned” so that there is very little high frequency ringing component in the output signal. However, some low frequency ringing is a side effect of this “tuning.” It is apparent that depending on decoder/loco motherboard combinations that this could be an issue with certain decoders or loco/decoder configurations....

Some samples of TCS (and other) decoders appear to display issues under control from the SELECT or ELITE controllers...

In practice it has been found that not all instances of the same decoder will display the same issues. It is therefore assumed that any running anomalies may be due to EMC issues .... It is unclear at this time whether TCS decoders demonstrate “stretched zero bit” intolerance; however, it is suspected that this may be the case in certain instances/models of TCS decoders. The issue is clouded by TCS having known issues caused by EMC intolerance. Also, it should be born in mind that not all samples of the same decoder behave identically in the same loco installation. Some loco PCBs appear to compound the problem....

The Select at v1.6 has DC running (stretched zero bit) disabled as default so this shouldn’t be in play. Select at v1.5 has it enabled as default. The answer is to try a different decoder in that loco.

[Brew Man]

I have this with one loco in particular. There may be others that I haven't yet run. I have tried a couple of different decoders but it makes little or no difference. The problem only seems to manifest when the loco is set to run at full speed, at which point I need to hit the panic button to bring it to a stand still. My only work around is to not run it full belt. Reading Rob's post above would point to it being a decoder PCB issue.

[Fishmanoz]

For me, a simpler explanation would be that, given you are using a 1 Amp PSU, the loco at full speed is marginally overloading your controller causing a voltage drop or momentary reset leading to DC Runaway.

But only if using 1 Amp.

With that, let’s not further hijack this thread before the OP comes back on the questions asked so we can improve our diagnosis for him.

[96RAF]

Try this suggested fettle from my files BM

Installing a 47Ω high wattage resistor** in the feed to the track may resolve any issues re erratic running and control.

**Select a resistor of at least 7W rating

Although a good decoder will have voltage clamping designed in to suppress track spikes the use of a bus terminator or snubber can also help with command unresponsiveness.

[Brew Man]

Thanks, Rob, I'll try that. I already have snubbers at each end of my bus, so it's not that.

[ntpntpntp]

There have also been reports over the years of some decoders reverting to DC mode if they encounter brief loss or interruption of the DCC signal due to dirty wheels or track (or other signal quality issues). Hence they no longer "listen" and just see the track as supplying full DC power and literally experience a runaway. It's why some people who run exclusively DCC choose to turn off the DC capability in their decoders.

[96RAF]

Many controllers now state that they no longer support DC running.

[BritInVanCA]

I’ll have to do a bit more testing but here is the initial response

• I’m operating in accordance to the 1.6 manual instructions
• power supply is Hornby C7033 (I’m in Canada). I don’t see an amp rating
• happens with on loco running. I have a simple double loop with wires soldered directly to the track. Works fine on DC with another controller
• only happens with two locos. Others are fine
• occurs at any speed settings usually running at about 50%
• loco speed continues with initial setting and does not speed up or slow down
• haven’t tried leaving it for a while

[BritInVanCA]

Directly wired to track via solder. No track connector

[BritInVanCA]

TCS, Bachmann and some other decoders have long since been known to play up with Hornby controllers. American decoders in particular as they fail to meet European EMC requirements.

This from my file notes...

The ELITE (and the SELECT) meets EN55014 EMC Electro Magnetic Compatibility Directive certification i.e. when under load as specified by the requirement. To meet this requirement the output of the ELITE/SELECT is “tuned” so that there is very little high frequency ringing component in the output signal. However, some low frequency ringing is a side effect of this “tuning.” It is apparent that depending on decoder/loco motherboard combinations that this could be an issue with certain decoders or loco/decoder configurations....

Some samples of TCS (and other) decoders appear to display issues under control from the SELECT or ELITE controllers...

In practice it has been found that not all instances of the same decoder will display the same issues. It is therefore assumed that any running anomalies may be due to EMC issues .... It is unclear at this time whether TCS decoders demonstrate “stretched zero bit” intolerance; however, it is suspected that this may be the case in certain instances/models of TCS decoders. The issue is clouded by TCS having known issues caused by EMC intolerance. Also, it should be born in mind that not all samples of the same decoder behave identically in the same loco installation. Some loco PCBs appear to compound the problem....

The Select at v1.6 has DC running (stretched zero bit) disabled as default so this shouldn’t be in play. Select at v1.5 has it enabled as default. The answer is to try a different decoder in that loco.

 

 

All very interesting and good background. Also interesting that this problem does occur with other controllers no matter what standard the chip is manufactured to I.e. NCE power cab works fine with European or North American chips. Also interesting that a Hornby dealer recommended TCS chips for Hornby locos and a Select controller

[Fishmanoz]

Thanks for answering those questions although they don’t add much to likely causes except - if you don’t know the current rating of the PSU, I’m going to assume it is the one that came with the Select new, and that is 1 Amp.

Upgrading to a 4 Amp supply will not only allow you to run more locos at once, it is also known to fix a number of seemingly random shortcomings in operation. So it may fix the problem, but then again it may not.

There is a Hornby compatible 4 Amp (default one that comes with Elite) but it is expensive and I have no idea if available in Canada (more likely is than not). But there is a well-known compatible 19v 4 Amp Toshiba laptop supply much cheaper via eBay. Trick is it is the one with the plug compatible with Select. This means the plug dimensions must be 6.3mm/3mm. Or the same as the one you have.

No guarantee it will fix your problem, there may still be decoder compatibility issues, but a worthwhile upgrade anyway.

[96RAF]

C7033 is the older Scalextric equivalent of the Hornby P9300 with a North American plug. There is also a P9303 for North America.

The amperage is seen here as the secondary winding output.

[Fishmanoz]

Oh dear, that’s my latest thoughts shot!

[BritInVanCA]

C7033 is the older Scalextric equivalent of the Hornby P9300 with a North American plug. There is also a P9303 for North America.

The amperage is seen here as the secondary winding output.

 

 

Yeah no amperage information on mine but I think you've answered the question. I guess I probably have to replace a couple of chips. I'm just old fashioned in how long I expect thinks to last. I should know better. I worked in IT for 35 years!

 

 

As always thanks for your help!

 

 

 

 

[LTSR_NSE]

@BritInVanCA - just for your information, on your supply next to Output, it says both 15V & 60VA.

(VA = VoltAmps i.e Volts x Amps) therefore 60VA divided by 15V = 4A so yours states that it is a 4Amp supply.

[P-Henny]

For further info.

VA is the same as W (Watts). The image in 96RAFs reply used the term 60.0W which is the same as 60VA. Voltage plus VA is used quite a lot on power supply labels to express current, but I agree that this can be confusing.

[96RAF]

@PH

I assume VA is now some industry standard for labels to cater for power supplies with adjustable outputs in that different voltages would provide different amperages within the quoted VA value.

[P-Henny]

@96RAF - Good point made.

[ntpntpntp]

I always assumed VA was an old standard, I associate it with ancient equipment from the 50s/60s/70s grinning I sometimes see people nit-picking about VA not equivalent to Watts due to power factors etc. but as a rough equivalent it's good enough for me.

[Fishmanoz]

There’s no etc, just power factor which arises with reactance v resistance.

Let’s not go there though, KISS best applied here.

[rpjallan]

Has anyone suggested making sure any capacitors have been removed from the motor?