Battery powered/Radio controlled locos

[Robin2]

For 2.4GHz the length of the antenna and its connection to the circuit board are critical. I suggest you do not tamper with a Deltang antenna without asking David Theunissen first.

 

...R

[SimonME46]

Going back to the 2.5mm Jack idea, a board such as this would take care of multicell balance problems. Cheap as chips too..

 

http://www.ebay.com.au/itm/2S-Li-ion-Lithium-Battery-18650-Charger-Protection-Board-Module-3A-7-4V-8-4V-New-/291666522316?hash=item43e8adf0cc:g:buMAAOSw5dNWof~f

 

Tramcar Trev on free rails used these I believe.

Edited August 7, 2016 by SimonME46

[Robin2]

I think that charging device would be a bit big to fit inside an 00 gauge loco. But I guess it doesn't have to - it could be on terra-firma and the loco hooks up to it.

 

Are there are any UK suppliers for it?

 

...R

[SimonME46]

I think that charging device would be a bit big to fit inside an 00 gauge loco. But I guess it doesn't have to - it could be on terra-firma and the loco hooks up to it.

 

Are there are any UK suppliers for it?

 

...R

That was me being selfish with O gauge, sorry. If it was on terra-firma, you'd still need a 3pin plug Etc rather than just a raw dc feed, so it just becomes a very cheap charging station, and a valid alternative to a step up board. I've ordered 10 just for the fun of it. They seem quite common. Edited August 7, 2016 by SimonME46

[davetheroad]

To my mind (weird and distorted as it is) we have the two issues which reflect the fact that model railways has big differences compared to the other radio control hobbies. We don't for example, charge up our trains and take them to an area of open ground/sky/water, play with them, and then go home. We have layouts, and tracks.

 

So we have two potential problems, one is with the aerials: we are not going to have a length of wire being held upright in a length of plastic tubing. We also frequently have metal bodied models. Given the more limited range we usually require for our layouts, I do not think this is an insurmountable obstacle, although the criticality of aerial length might be an issue for 2.4 GHz in some applications.

 

The other is with the fact that we like to leave our models on the layout, if possible, and to keep handling to a minimum. We also have very different power requirements, especially to model aircraft. We don't need need to be able to output high power, so high C ratings are not for us. (Good: this makes the batteries cheaper!) but we do frequently need up to 12v, unless we re-motor everything and don't wish to use DCC on-board sound. Now, I know that the latter is not for everyone and that's OK, but putting in lower voltage motors isn't everyone's cup of tea, either. It turns a potentially simple alternative system into something much more demanding. Finally, the batteries and cells themselves are designed generally to be long and thin. This is not always what we want, either. A round (for steam era) or nearly square (for diesels) cross-section, with varying lengths, suits us better. (I am aware of cylindrical cells, but they seem to be 1S only.)

 

Also, the websites which sell these batteries are - not surprisingly - geared up to sell mostly based on capacity and weight: what I want to be ale to do is specify the maximum dimensions for length, width and height, and see what I can get into that space! Ideally, for 12v motors and anyone with DCC sound decoders, a 3S supply is needed, but this then requires balance charging and can be a problem with finding enough save for the battery pack.

 

The obvious solution to this is, of course, a 1S cell with a reasonably high amp-hour capacity, and to use a voltage regulator circuit to step-up the voltage, albeit at the loss of some power (I believe 20%) and a shortening of running time. (If you increase the voltage by a factor of three, then you will only be angle to provide the same level of current for 1/3 of the time.)

 

Because we don't take our engines back home to the work bench for a wipe down, clean-up, etc, and are unlikely to have easily detachable superstructures and body shells or easily located multi-pin balance charger plugs, re-charging batteries via a plug and socket in anything smaller than 0 gauge is likely to be a major pain in the proverbial.

 

However, we do have in most of our models a 2-pole connecting to the motor built in: I refer of course to the rails, via the wheels and whatever pickup system is used. So why not make use of this more?

 

I am not talking about having all-wheel pickup, just one or two wheels each side taking current and nor I am suggesting that we have all of the track live. Just a few sections of track wired up to a trickle charge supply: anywhere where engines (and multiple units) stand. Engine sheds, headshunts, either or both ends of platforms. For those who want to be really fastidious, just the engine fuelling points. We could charge batteries rather than just cells, but this then requires on-board circuitry (more space used up), so a 1S battery with voltage regulator (ready made circuits from, e.g. pololu, are tiny - and cheap!) on the output side makes sense again.

 

My point is that unless systems are plug and play, with nothing more required than plugging something into the now almost standard DCC socket on engines, then BPRC will remain the exclusive domain of those who are prepared to source the various bits themselves, and get the soldering iron out. What that means, I suppose, is a single circuit board containing the voltage regulator and receiver, simple charging circuit (including a bridge rectifier so that DC, AC and DCC can be used as sources of charge for the cell) with a lead to a 6/8/22 pin plug, and sockets for the power cell and an on/off switch (the circuit for which would be on the main oard). Such a system would not need to be very big, and would work well with a variety of 1S batteries: 14500 or 18650 in the boiler, cuboid elsewhere, etc. For wireless DCC, I would look to seeing all that circuitry being eventually included on the decoder, and interim steps might again require a bit more work, but you get the point.

 

Something that simple would be much more likely to engage the interest of railway modellers, and is designed for rather than against our particular needs.

 

And please, no posts from the already converted about it not being a big deal to plug in a charger, or wire things up, etc. That's not my point. For BPRC to become more popular, it needs to be more accessible, otherwise those who are using risk becoming seen as an odd group at best, or of being accused of elitism at worst.

 

So, what about something simple, making use of just a couple of pickups, with minimal (if any) soldering required for those taking the plunge?

What you need is for bluerail to modify their board so it charges the onboard battery when power is available.

 

ps - I have several points in your post that I sort of disagree with but as you say I am already converted and have done the hard/fiddly bits!.

[Robin2]

I started with the idea of charging my N Gauge locos from the rails (with just a small section live for charging).

 

The first problem is that the loco can be put on the rails either way round so you need a rectifier onboard to allow for the wrong polarity. That takes up space.

 

The next problem is that the track voltage must be a suitable charging voltage. With a 1S LiPo on board you daren't put the loco on a 12v track. And an onboard charge controller is another item that takes up space.

 

My present thinking (for 00 Gauge) is to use a pair of LiPo cells, a replacement motor, no wheel pickups so that the loco can run on any track (for example a club layout) and three discrete connectors arranged so that the loco can drive into a charging point - perhaps inside an engine shed. This should minimize the amount of space needed inside the loco.

 

Simon's point

 

For BPRC to become more popular, it needs to be more accessible

is very valid. But I think the sort of solutions he wants must be built in when the loco is being designed and that won't happen until us "odd group" have brought the concept far enough for the technology to be appreciated - even if our implementations are not as simple as the mass-market consumer would like.

 

...R

Edited August 8, 2016 by Robin2

[davetheroad]

Model trains may be fundamentally different to boats and planes but I find I use mine in a similar manner. A full on comprehensive operating session uses about 16 locos with about 24 batteries. I simply pop fully charged batteries in the locos at the start of the session, it takes less than 1 minute per loco. At the end of the session I remove the batteries and recharge them. A 'normal' operating session might only have a few locos, maybe 4 or 5.

 

I use E-flite style 1S batteries and connect them in series for locos drawing more than about 0.4A . I find using 9V through a Pololu voltage regulator gives plenty of power, enough to have my large 4-6-2 pacifics pulling a 12 coach train at over a scale 60mph which is what I am comfortable with for my fiddle yard curves. The charging is via an E-flite 4 battery charger and 2 USB chargers so I can charge 6 batteries at the same time.

 

I am always removing engines from the track, using Peco loco lifts, I also remove most of the fiddly bits such as brake rodding etc as I will knock them off anyway and I can't see them at operating distances!.

[davetheroad]

Oh, I agree with that entirely, but the challenge is still there. I think things are getting close: the concept has been proved very successfully for direct RC control to replace DC. As I have said on this and other threads, model rails are fundamentally different to model cars, boats and planes, and need a different approach. A simple, low current, bridge rectifier can be made using 4 diodes and small ICs are available to do this: easily incorporated into a small PCB. A single circuit board is already more than enough for many, but more than one is definitely too many for a commercial solution.

 

I don't mind plugging a charger into a discrete socket, but by discrete I mean, "Not visible in normal operation" and also removing engines from the track is a no-no. I suppose that we may eventually move towards inductive charging.

 

Is this where you don't have a controller as such, but a power supply is connected to the rails via a radio receiver and what you have is essentially a DC layout with a walk about controller?

[Robin2]

My point is, it works, but until it is as simple as plugging something into a DCC ready socket, and as long as charging batteries involves manual handling, I can't see it becoming what it could become.

But how do we get frome here to there - because "here" is the only starting point.

 

IMHO the focus should be on what we are able to achieve rather than the shortcomings. If people are impressed by the achievements someone will work on the shortcomings.

 

I have no idea whether BPR/C will ever become mainstream, but I would not be prepared to stop messing with it even if I knew that it had no mainstream future.

 

...R

[dan3192]

But how do we get frome here to there - because "here" is the only starting point.

 

IMHO the focus should be on what we are able to achieve rather than the shortcomings. If people are impressed by the achievements someone will work on the shortcomings.

 

I have no idea whether BPR/C will ever become mainstream, but I would not be prepared to stop messing with it even if I knew that it had no mainstream future.

 

...R

 

I agree with Robin we need to focus on what we can achieve. But I also find shortcomings a convenient guide to reaching such achievement. Someone once said, understanding the problem is half the solution. It seems quite true.

 

But to the point of the discussion, about a year ago I started working on ways to charge batteries on-board so as not to have to remove them, mess up my handrails or rely on dirty track for transferring the required power. As a result, I expect to shortly complete a BPRC engine with 2S on-board balancing charging capability that does not need plug-in wiring or contact with the track. If you are thinking magnetic induction, you are correct.

 

With the help of a large electronics firm, I have just about all the parts I need, I've done basic testing, and it seems to work. 3S and 4S charging is also possible and will come later. I am also interested in a 2S2P arrangement. A big challenge is fitting in all the components and wiring up properly. I have no problems working with Li-ion batteries, but I do know the consequences if you don't get it right the first time. I hope to report back the tests were successful.

 

IMHO, I believe BPRC will become either mainstream or a big player in model railroading cab control. I've given 10 clinics on BPRC in the last 3 years and operated on many club and home layouts and have personally witnessed the growing interest by hobbyists. The DCC sound decoder equipped BPRC steam engine I described here 2 years ago is still going strong, so enjoying the hobby more than ever.  

 

Dan     

Edited October 22, 2016 by dan3192

[Robin2]

I expect to shortly complete a BPRC engine with 2S on-board balancing charging capability that does not need plug-in wiring or contact with the track. If you are thinking magnetic induction, you are correct.

This is interesting. What scale/gauge are you working with?

 

Can you post a link to the datasheets for the devices you are using for induction?

 

So far I have been thinking of balance charging by exposing 3 discrete wires at the end of a loco that will make contact when it runs up to a set of buffers. Of course this has the advantage that the balance electronics are not taking up space on the loco.

 

...R

[rdr]

This thread takes me back a few decades when i radio controlled a 00 Lima Western. After spending many years in the rc world with 1/10 scale cars, nicads and 27mhz rc, it was a reasonably easy method to go down. These days with Lipos and miniature receivers/speed controllers it's so easy a child could do it.

 

What first sold it to me was the level of control you have and the smoothness of the loco over the rails, and realism is what we want, isn't it?. This old Lima Western running from a 9v PP3 battery was a joy to see, you could even see a slight resistance on the loco when it went through the points.

 

Recently i spent a year in the club level 1/10 radio control car scene, and now battery life is massive compared to the old days, but battery management is critical. Reading through the posts placed here, i've noticed that there is a lot of emphasis on battery balancing when charging. This is a requirement when you're after absolute peak performance from the 2S or 3S packs, but not a must do. More important is the limitation on the charging voltage the batteries are charged too, any excess here and that's the end of the battery.

 

Another point to be raised is the method of charging, some have mentioned trickle charging through the rail/wheel pickups, but also some have thought about using "jack plugs". NO IS THE ANSWER TO THAT IDEA, jack plugs will short the supply temporarily when they are plugged in, and the last thing a lipo battery want's to have is a direct short.

 

A lipo failure is an event to be witnessed, is doesn't take long, but it is entertaining or not depending on what the lipo is in. A certain item from Samsung springs to mind, the Galaxy Note.

 

An idea i thought of for charging, would be two small studs underneath the loco wired to the battery and a corresponding set of sprung pins/pads for the loco to ride over at a specific place on the layout or in the fiddle yard, easy and simple.

 

Another good point worth mentioning, is a lot of rc handsets have multiple model memories that hold the finite settings for that specific model. Some handsets will isolate each receiver when changing the model and only run the actual model selected, which gives a handset the capacity to run a large amount of trains without turning each model off. Beware, some handsets will only change the settings and leave the model functioning.

 

It's going to be a hard task to convert the massive community of DCC users over to rc, but they were converted from analogue once, so there is a hope.

 

PS, The next time your loco stops over a point or judders again, think of rc.

[Robin2]

PS, The next time your loco stops over a point or judders again, think of rc.

That says everything that needs to be said 

 

...R

[phil_sutters]

 

An idea i thought of for charging, would be two small studs underneath the loco wired to the battery and a corresponding set of sprung pins/pads for the loco to ride over at a specific place on the layout or in the fiddle yard, easy and simple.

 

Last week my grandson bought a radio-controlled helicopter for £7. It was tiny. The counter rotating rotors couldn't have been more than 12cm across. It performed amazingly well and was quite robust. It recharged, after about 20 minutes flying time, by sitting on the control handset, taking power from its 3AA batteries. I didn't look to see how the contact was made, but I suspect it was via the two undercarriage skids. Certainly there were no plugs involved*. I can see an obvious location for the recharge - the coaling stage or the diesel refueling point!

I am really quite surprised that railways are trailing behind planes, ships and trucks by such a long way. I expect it is due to the existence of a means of powering and control for railways, that generally didn't exist for other types of transport. I know there have been trucks on long leads and Scalextric type car tracks, but in general r/c, once available, was the only way to go and now battery technology is advancing so fast, it creates many new possibilities.

* 1.11.2016 As grandson & helicopter came round this afternoon, I have now established that there is indeed a plug - it is a rigid plug to socket connection, a bit like a USB one. I am sure that there are many options for recharging - including induction - like my electric toothbrush.

Edited November 1, 2016 by phil_sutters

[davetheroad]

Talking about battery development I remember the senior engineer commenting about why their very promising new technology started failing after a few months use. He said the problem was we don't really know how this stuff works at a molecular level.

 

On a positive note - I have lost the link to the BBC item. They showed a new technology based on sulphur? that could give up to 5 times? the capacity. Apparently the problem with sulphur is bits break off the anode and degrade the battery so they engineered the anode to have the same characteristics as the inside of your intestine. All those sticky out hair like structures trap the bits that fall off so they still function. The downside is less recharge cycles but this is countered by more time between recharges. Hope it works.

 

For those with more space for the batteries how about Lithium Ferric Phosphate?. It appears they are safer, deliver nominal 3.2V and are available in AA size with 400mAh or 600mAh. They just fit in 00 scale body width and a pair with a 9V voltage booster might work. Pity an AAA size is not available.

 

For those with plenty of space you have NiMH at 1.2V per cell. AAA size can have up to 1000mAh? and You can fit 4 of them in a 00 coach or wagon giving 4.8V for your voltage booster.

[Robin2]

. I find using 9V through a Pololu voltage regulator gives plenty of power, enough to have my large 4-6-2 pacifics pulling a 12 coach train at over a scale 60mph which is what I am comfortable with for my fiddle yard curves.

Sorry if I am a bit late with this question, but I am wondering is this the Pololu voltage regulator you were referring to?

 

And does it get hot in use?

 

Thanks.

 

...R

[davetheroad]

Sorry if I am a bit late with this question, but I am wondering is this the Pololu voltage regulator you were referring to?

 

And does it get hot in use?

 

Thanks.

 

...R

 

No, it is this one https://www.pololu.com/product/2116

 

It has integrated thermal protection and I have never noticed one getting hot.

[Robin2]

No, it is this one https://www.pololu.com/product/2116

 

Many thanks.

 

Edit to add ...

 

Just wondering where you bought them as the 9v version does not seem to be commonly available.

 

...R

Edited February 5, 2017 by Robin2

[davetheroad]

Many thanks.

 

Edit to add ...

 

Just wondering where you bought them as the 9v version does not seem to be commonly available.

 

...R

 

Well timed!

 

I was about to buy some and my original source no longer seems to stock them, however try this

 

http://www.makertronics.co.uk/9v-output-voltage-regulator-modules-en/

[Robin2]

Thanks. I had come across Makertronics and also Robotshop

 

I have not done business with either. Robotshop seems to offer bulk discounts.

 

I can't see where Makertronics is based.

 

...R

[aforsyth]

Looks like they're based in Rugby on this page:

https://www.makertronics.co.uk/contact-us-en-2.html

 

I'll be interested to hear how people get on with the voltage regulators for 9V - what battery combination did you use for the input, davetheroad? [sorry, can't find your original post if that had details].

 

Thanks. I had come across Makertronics and also Robotshop

 

I have not done business with either. Robotshop seems to offer bulk discounts.

 

I can't see where Makertronics is based.

 

...R

[davetheroad]

Looks like they're based in Rugby on this page:

https://www.makertronics.co.uk/contact-us-en-2.html

 

I'll be interested to hear how people get on with the voltage regulators for 9V - what battery combination did you use for the input, davetheroad? [sorry, can't find your original post if that had details].

 

I use single or double cell lipos depending on the current draw of the locomotives. The efficiency of the Pololu regulator depends on the input voltage and output voltage.

 

For locos drawing less than 0.35A I use a single cell lipo delivering a nominal 3.7V and I have the power shutdown set at 3.4V

 

For locos drawing over 0.35A I use 2 cells in series delivering a nominal 7.4V with the power shutdown set at 6.8V. With 2 cells the Pololu gives good efficiency for locos drawing over 0.7A

 

The regulator is available in 5V, 9V and 12V versions. I find that 9V works well for me as a large pacific loco can haul 12 coaches at over scale 60mph using 9V.

[Robin2]

Looks like they're based in Rugby on this page:

https://www.makertronics.co.uk/contact-us-en-2.html

Thanks. I foolishly expected that information to be on the About Us page

 

...R

[Robin2]

For locos drawing over 0.35A I use 2 cells in series delivering a nominal 7.4V with the power shutdown set at 6.8V. With 2 cells the Pololu gives good efficiency for locos drawing over 0.7A

 

I'm glad you said that because I was hoping to use the device to avoid the need for two cells and balanced charging. With the motor I have put into the loco 7.4v is sufficient, and would also be sufficient for a couple of other locos I have tried with their original motors so I don't think I have a need to boost from 7.4v to 9v.

 

I guess I could use two of them in parallel for more amps. But then it starts to get expensive. And takes up space.

 

Time to dig out the thinking cap again.

 

...R

[Junctionmad]

This thread takes me back a few decades when i radio controlled a 00 Lima Western. After spending many years in the rc world with 1/10 scale cars, nicads and 27mhz rc, it was a reasonably easy method to go down. These days with Lipos and miniature receivers/speed controllers it's so easy a child could do it.

 

What first sold it to me was the level of control you have and the smoothness of the loco over the rails, and realism is what we want, isn't it?. This old Lima Western running from a 9v PP3 battery was a joy to see, you could even see a slight resistance on the loco when it went through the points.

 

Recently i spent a year in the club level 1/10 radio control car scene, and now battery life is massive compared to the old days, but battery management is critical. Reading through the posts placed here, i've noticed that there is a lot of emphasis on battery balancing when charging. This is a requirement when you're after absolute peak performance from the 2S or 3S packs, but not a must do. More important is the limitation on the charging voltage the batteries are charged too, any excess here and that's the end of the battery.

 

Another point to be raised is the method of charging, some have mentioned trickle charging through the rail/wheel pickups, but also some have thought about using "jack plugs". NO IS THE ANSWER TO THAT IDEA, jack plugs will short the supply temporarily when they are plugged in, and the last thing a lipo battery want's to have is a direct short.

 

A lipo failure is an event to be witnessed, is doesn't take long, but it is entertaining or not depending on what the lipo is in. A certain item from Samsung springs to mind, the Galaxy Note.

 

An idea i thought of for charging, would be two small studs underneath the loco wired to the battery and a corresponding set of sprung pins/pads for the loco to ride over at a specific place on the layout or in the fiddle yard, easy and simple.

 

Another good point worth mentioning, is a lot of rc handsets have multiple model memories that hold the finite settings for that specific model. Some handsets will isolate each receiver when changing the model and only run the actual model selected, which gives a handset the capacity to run a large amount of trains without turning each model off. Beware, some handsets will only change the settings and leave the model functioning.

 

It's going to be a hard task to convert the massive community of DCC users over to rc, but they were converted from analogue once, so there is a hope.

 

PS, The next time your loco stops over a point or judders again, think of rc.

 

 

 

The main thing thats seems to get forgotten is that layouts have points , signals, track/block  circuit detection, fixed lights etc etc , a model locomotive is Not the same thing as a model boat or a model plane, unlike the others it has to exist on a " layout ".

 

this means we still have plenty of wiring and in fact adding DCC wiring is not much of an additional chore 

 

 

 

PS, The next time your loco stops over a point or judders again, think of rc.

yes get proper points, and proper  loco pickup and no judders.  DCC is capable of providing excellent slow speed running better then DC , and slower then the prototype typical operated at.  

BPRC will be a niche and the best off luck to it . people over estimate the complexity of wiring track.