Hornby APT (2020 tooling)

[JSpencer]

15 hours ago, Pete the Elaner said:

 

Would you have considered it a white elephant if they hadn't bothered with lighting? I doubt they would have been any cheaper.

Once somebody works out how to get the body apart, it will be possible to move the capacitor or even disable the lighting completely. We may well get body removal instructions with the 5/7 packs like we do with locos.

 

As I said in my previous post, the interior lighting is a bonus for me considering they were not part of the original spec.

 

With or Without lighting, I can argue it's something of a white elephant for me personally considering I mainly model the South East. But it was "the" train I wanted as a kid, as my parents said "No, you already have an HST". And I collected many magazines with photos of this train. Eventually I did get a secondhand Hornby APT 15 years later, somewhat scruffy, limited to 5 cars.... And not quite a 8-10 car set I had seen in photos which I thought made a decent size for a layout. 

 

I got the Rapido APT-E which makes a compact train even though never a south east item. But the all new complete APT train is a dream come true.

That said, the APT-P was sufficiently enough a white elephant that I never went for the DJM model (for many reasons). 

 

My layout can cope with a 14 car set on the outer loop only, although it will somewhat dwarf the layout. 10 cars will probably be typical for me, or maybe 11 with the experimental APT-U coach.

[Roy Langridge]

39 minutes ago, JSpencer said:

 

As I said in my previous post, the interior lighting is a bonus for me considering they were not part of the original spec.

 

With or Without lighting, I can argue it's something of a white elephant for me personally considering I mainly model the South East. But it was "the" train I wanted as a kid, as my parents said "No, you already have an HST". And I collected many magazines with photos of this train. Eventually I did get a secondhand Hornby APT 15 years later, somewhat scruffy, limited to 5 cars.... And not quite a 8-10 car set I had seen in photos which I thought made a decent size for a layout. 

 

I got the Rapido APT-E which makes a compact train even though never a south east item. But the all new complete APT train is a dream come true.

That said, the APT-P was sufficiently enough a white elephant that I never went for the DJM model (for many reasons). 

 

My layout can cope with a 14 car set on the outer loop only, although it will somewhat dwarf the layout. 10 cars will probably be typical for me, or maybe 11 with the experimental APT-U coach.

 

I am much like you - the APT is not really my region but having seen the real thing a handful of times and travelled on it once from Crewe to Stafford late one evening*, it had to be bought. The new track I will have round my new home office will allow me to run the full 14 coach set, without looking TOO silly. It won't really be much of a layout, just somewhere that I can watch and hear trains go past whilst I work .

 

If I can get into the coaches safely then I will rip out the Hornby provided boards and add my own DCC controlled lights.

 

Roy

 

Edit: * I was doing a week of overnights at Crewe on a rover ticket (may have been a Heart of England?) and the APT had been about on test a couple of evenings. One of the last nights I was having a good gander at it and I was asked if I wanted to have a ride. After thinking about if for about 0.1s I got on board. An amazing experience and one that I will never forget. At some point I will dig out my records for which units it was. The problem was I don't think back then I recorded the individual coaches, so probably just have the end numbers.

 

 

Edited October 21, 2021 by Roy Langridge

[phil-b259]

12 hours ago, ac1874 said:

Oh dear, hope this is not a common issue, a visible capacitor that doesn't do anything!

 

https://www.facebook.com/groups/268189996609618/permalink/4314322855329625/

 

 

That shows an ignorance over how capacitors work!

 

Capacitors in consumer electronics can only supply stored charge for a matter of milliseconds at most. To supply charge for a few seconds or more it would need to be physically larger than a OO gauge train body.

 

As has been said, capacitors are primarily there (when talking about DC voltages) to smooth out any imperfections in supply. If you want to maintain power during outages (even if they are only for a couple of seconds) then you need a battery back up / mini UPS system

[lyneux]

This chap claims his small set of LEDs stay on for 5 seconds with a 1000 uF capacitor: 

 

Edited October 21, 2021 by lyneux

[Roy Langridge]

20 minutes ago, phil-b259 said:

That shows an ignorance over how capacitors work!

 

Capacitors in consumer electronics can only supply stored charge for a matter of milliseconds at most. To supply charge for a few seconds or more it would need to be physically larger than a OO gauge train body.

 

As has been said, capacitors are primarily there (when talking about DC voltages) to smooth out any imperfections in supply. If you want to maintain power during outages (even if they are only for a couple of seconds) then you need a battery back up / mini UPS system

 

I am not sure how my DCC Power Packs (a capacitor) manage to power my locos on DCC with sound for several seconds then! See: https://www.youtube.com/watch?v=yJeGuHCilP4 as an example.

 

I would expect a fully charged 1000uf capacitor to be able to power the 8 SMD LEDs for long enough to see them working (not seconds I agree).

Roy

Edited October 21, 2021 by Roy Langridge

[Steven B]

I'd be worried about the rating of the capacitor - 16V doesn't give much overhead when operating on DCC powered track (even allowing for the Voltage drop across the diodes).

 

Steven B.

[newbryford]

7 minutes ago, Steven B said:

I'd be worried about the rating of the capacitor - 16V doesn't give much overhead when operating on DCC powered track (even allowing for the Voltage drop across the diodes).

 

Steven B.

 

Especially when using a Hornby Elite... Some nice voltage spikes:

https://www.picotech.com/library/application-note/dcc-demonstrating-the-Hornby-elite-using-picoscope

[AY Mod]

1 hour ago, phil-b259 said:

To supply charge for a few seconds or more it would need to be physically larger than a OO gauge train body.

 

Ahem.

 

 

[Roy Langridge]

11 minutes ago, AY Mod said:

 

Ahem.

 

 

 

I tried to find that for my post above and failed...

 

And the truth is rather than only powering for milliseconds, the power packs are so strong you often have to limit how long they will run for using the CVs. I think my power-pack fitted Bachmann Peak will run for about 8 seconds, with sound (not at max volume).

Roy

[phil-b259]

1 hour ago, Roy Langridge said:

 

I tried to find that for my post above and failed...

 

And the truth is rather than only powering for milliseconds, the power packs are so strong you often have to limit how long they will run for using the CVs. I think my power-pack fitted Bachmann Peak will run for about 8 seconds, with sound (not at max volume).

Roy

From Wikipedia (and I have no reason to doubt it)

 

Conventional capacitors provide less than 360 joules per kilogram of specific energy, whereas a conventional alkaline battery has a density of 590 kJ/kg. There is an intermediate solution: Supercapacitors

 

https://en.wikipedia.org/wiki/Supercapacitor

 

I therefore suspect that the capacitors used in the A class shown above (and similar) are not bog standard electrolytic capacitors as per the Hornby APT.

[WestRail642fan]

8 hours ago, PaulRhB said:

 

 

I conducted my own little experiment and let the capacitor sit and charge for 30secs, 1 min then 2 mins and there was no noticeable change in the lights going out almost immediately. It’s only got enough capacity to reduce flicker not eliminate it really so I’d agree pretty pointless. The only thing the experiment made me think is I wish they’d included a switch as it’s way too bright for daytime running! No worries I’ll just bend the contacts slightly off the wheels and not worry about hiding the cap as the tiny works quite nicely with the lights off. 

i left my coaches on the track with full power for about 5-10 minutes, the capacitorb does work for 2-ish seconds after cutting power

[phil-b259]

2 hours ago, Roy Langridge said:

 

I am not sure how my DCC Power Packs (a capacitor) manage to power my locos on DCC with sound for several seconds then! See: https://www.youtube.com/watch?v=yJeGuHCilP4 as an example.

 

I would expect a fully charged 1000uf capacitor to be able to power the 8 SMD LEDs for long enough to see them working (not seconds I agree).

Roy

 

Depends on the circuit configuration - while LEDs don't pull much current things like limiting resistors can thus quickly depleting the cap. Also if the cap is the 'supply side' of any regulator chip then that may reduce its effectiveness.

[Roy Langridge]

2 minutes ago, phil-b259 said:

From Wikipedia (and I have no reason to doubt it)

 

Conventional capacitors provide less than 360 joules per kilogram of specific energy, whereas a conventional alkaline battery has a density of 590 kJ/kg. There is an intermediate solution: Supercapacitors

 

https://en.wikipedia.org/wiki/Supercapacitor

 

I therefore suspect that the capacitors used in the A class shown above (and similar) are not bog standard electrolytic capacitors as per the Hornby APT.

 

Don't believe everything on Wikipedia, in fact don't believe most of it. 

 

As @lyneuxposted above, there is a circuit using bog standard electrolytic capacitors giving 5 seconds of bright lighting and 30 seconds of some light. A capcitor will discharge quickly if allowed to, but if the delivered current is constrained, it will provide that charge over a period.

Roy

[Roy Langridge]

2 minutes ago, phil-b259 said:

 

Depends on the circuit configuration - while LEDs don't pull much current things like limiting resistors can thus quickly depleting the cap. Also if the cap is the 'supply side' of any regulator chip then that may reduce its effectiveness.

 

Certainly that voltage regulator is having a bearing, and I suspect that is why there is no noticeable benefit from the capacitor. Modern quality SMD LEDs operate at about 1mA, so even were the capacitor delivery a very small current, the demand is equally small.

Roy

 

[AY Mod]

Another consideration: the IRM capacitors only function on DCC. No one's got an APT driving vehicle yet to see if they perform better on DCC.

[PaulRhB]

Scoobyra has got one apart and I’ve asked him to post it here as the clips are further in than we thought from the instructions leaflet  

[Roy Langridge]

19 minutes ago, WestRail642fan said:

i left my coaches on the track with full power for about 5-10 minutes, the capacitorb does work for 2-ish seconds after cutting power

 

That is more what I would expect from a 1000uF capacitor. I wonder why @PaulRhBgot no discernible benefit? Will test mine at the weekend, both on DC and DCC.

 

What I can't see on the boards is the resistance on the supply side of the capacitor. The time for a capacitor to fully charge is 5 x R x C. We know C is 0.001 but not what R is.

 

Roy

[Roy Langridge]

7 minutes ago, AY Mod said:

Another consideration: the IRM capacitors only function on DCC. No one's got an APT driving vehicle yet to see if they perform better on DCC.

 

Why do we need a driving vehicle to see on DCC? I know you have something in mind, but I can't work out what.

 

Edit: Ok - worked it out!

Roy

Edited October 21, 2021 by Roy Langridge

[Mr_Tilt]

25 minutes ago, Roy Langridge said:

 

Don't believe everything on Wikipedia, in fact don't believe most of it. 

 

 

As the high-ups there won't let you correct blatant lies that are posted there, I'm not surprised in the slightest!  

[AY Mod]

Just now, Mr_Tilt said:

 

As the high-ups there won't let you correct blatant lies that are posted there, I'm not surprised in the slightest!  

 

The trolls have more time and motivation than the maligned. There is no proper control when it's lies and libellous.

[PaulRhB]

Ok it wasn’t Mikes pic to share but there are three clips on the lower body moulding. 
 

Pressing in the lower body, not the upper window part. 
 

 

 

Edited October 21, 2021 by PaulRhB

[lyneux]

I did a quick test of my trailers on DCC earlier this afternoon. I'd say the lights last about a half a second after removing from the track. Hard to tell as the LEDs fade out gradually so hard to tell the difference between on and off once they get dim. Should be enough to smooth out any momentary interruption from dirty pickups though.

 

FWIW, the capacitors charge in a few seconds so no need to leave them on the track for ages to test. There are calculators out there on the web that tell you how long a cap takes to charge to supply voltage based on various factors.

 

Guy

[adb968008]

47 minutes ago, Roy Langridge said:

 

Don't believe everything on Wikipedia, in fact don't believe most of it. 

 

As @lyneuxposted above, there is a circuit using bog standard electrolytic capacitors giving 5 seconds of bright lighting and 30 seconds of some light. A capcitor will discharge quickly if allowed to, but if the delivered current is constrained, it will provide that charge over a period.

Roy

2 mins in to this video you can see the performance of the Hornby mk2e with the x11547 board, vs the Bachmann mk2f without the capacitor on DC.

 

 

Scroll to 2mins.. you can see the delay as DC fades out.

 

As a DC operator, I like it, it smoothes over bad rail joints and a slight delay. ive stripped around 30 coaches from ebay of this light fitting and re-used them on my stock, a relatively cost neutral exercise.
 

I’m moving towards CR2032 battery operateds though now.

Edited October 21, 2021 by adb968008

[Wolf27]

I remember when this topic was about the APT. Now it’s become an electronics thread. 

[Roy Langridge]

3 minutes ago, Wolf27 said:

I remember when this topic was about the APT. Now it’s become an electronics thread. 

 

Still closer to topic than half the threads that wander off. At least we are trying to fix one of the apparent APT deficiencies.

 

9 minutes ago, PaulRhB said:

Pressing in the lower body, not the upper window part. 

 

Don't seem to get much inward movement on the lower part of my TRBS. I obviously need to be braver!

Roy