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Keybrick One / Rechargeable battery pack for Powered Up

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Tired of having to buy these AAA batteries for your Powered Up trains again and again? I'm testing a possible solution here:

 

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Wow! Very nice, very clean, very impressive.

Now, when V2 comes out with recharging with 9 - 18 V while operating, I will retrofit all my 2I/O hubs with this product.

Keep up the very good work!

Best
Thorsten

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In for one! Hopefully the price can come down on this as your start picking up steam. I think $50/EUR 40 would be a good target price point. And as I proposed earlier, an add-on that gives a 10-15cm USB extension with the connector built into a 1x2 brick would be very helpful. That could retail for EUR10/$10.

Edited by Phil B

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2 hours ago, Toastie said:

Wow! Very nice, very clean, very impressive.

Now, when V2 comes out with recharging with 9 - 18 V while operating, I will retrofit all my 2I/O hubs with this product.

Keep up the very good work!

Best
Thorsten

Thanks!! We may actually look into this very very soon-ish. As I said it'll be an add-on rather than integrated within a "v2". Having that said, I might need a beta-tester for that addon... so if you happen to have a Keybrick already :innocent: no promise on the exact timeline though.

1 hour ago, Phil B said:

In for one! Hopefully the price can come down on this as your start picking up steam. I think $50/EUR 40 would be a good target price point. And as I proposed earlier, an add-on that gives a 10-15cm USB extension with the connector built into a 1x2 brick would be very helpful. That could retail for EUR10/$10.

Thank you so much! The 40€ will be tough (at least  if that includes shipping) even if we manage to switch to an injection molded case, with currently an average of 11.xx€ (net) going torwards shipping. Now, if quantities rise significantly, some local retailer may end up being able to spread that over many units. But not for tomorrow I guess :(

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I'm also hoping for version two. Here are my thoughts and reasons why I'm not ordering the current product:

  • The battery recharging hassle is the main customer pain point of the Lego hub but unfortunately it is not addressed by the Keybrick One. The USB connector is as inaccessible from the outside of a train as Lego's battery holder, thus no improvement. Wireless charging or power pickup wheels would be required.
  • No slowdown: Nice to have, but I implicitly compensate the decreasing voltage by using a higher speed step. Of course this only works when not using the highest speed step with fresh batteries, which I rarely do, so that there is a margin to compensate the voltage drop.
  • Less weight is an anti-feature. The more weight the better to have enough traction. All my trains suffer from slipping wheels in inclines so I build them as heavy as possible.
  • Eco, normal and boost mode: Using a slower speed increases the battery live, but why should I limit it in the battery box if I can have the same result by just not using the highest speed level?
  • The LED indicating the mode cannot be seen when the battery box is inside the train, making it impossible to change the mode without disassembling the train. A beeper instead of the LED would be more useful.
Edited by legotownlinz

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5 hours ago, legotownlinz said:

No slowdown: Nice to have, but I implicitly compensate the decreasing voltage by using a higher speed step. Of course this only works when not using the highest speed step with fresh batteries, which I rarely do, so that there is a margin to compensate the voltage drop.

That works for manual control but as soon as you try automating a layout the rapidly changing power outputs make it a no go

 

eg, I’ve been playing with “speed limits” on sections, allowing full speed on express straights etc, and limits on curves, station entries etc, doesn’t really work when the necessary speed limit at full battery results in no progress 10 Minutes later

Edited by Stux

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7 hours ago, keybrickone said:

As I said it'll be an add-on rather than integrated within a "v2".

Hmmm. That puzzles me. Looking at your device, there is only one port: the USB socket (well and the switch actuated by a magnetic field large enough). So an add-on would attach to the USB port, right. I assume you are using the USB power lines only(?). Which means that your device, when charged with 5V off the USB port can already simultaneously provide power for running the 2I/O hub? Otherwise I don't understand how an add-on can accomplish that with your V1 version.

If so, the add-on would be a "5V power supply", correct?

Oh, I'd beta test whatever so see fit. Already tested the LEGO LiPo 10 years ago - to the extent of that one shrugging me off (at supplying 20(+)V DC charging voltage), just to tell me: Just kidding after 2 days or so.

Best wishes,
Thorsten 

 

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7 hours ago, keybrickone said:

As I said it'll be an add-on rather than integrated within a "v2".

Please do it right and support a wide voltage range directly in Keybrick Two. Any external solution is a mess because

  • it requires extra space
  • it is complicated to connect homebrew stuff
  • it's more likely the Keybrick gets damaged
  • electronics is required for every addon

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3 minutes ago, legotownlinz said:

Any external solution is a mess because

Well - no, isn't it? Again, let us assume these devices can do 5V charging off from the USB socket; which they can, of course.

Then the socket itself renders it sort of stupid not to go with 5V charging. Of course, homebrew stuff always carries the chance of damage. On the other hand - I believe all idiot proved solutions belong to TLG and the like. When applying 240V AC to an USB port - well then: Go studying.

See, any external device plugged into 8878 may damage it - as TLG suggests - provided it is not a 10V DC power supply. Which is stupid in itself, we amply talked about that here on EB.

Homebrew - at least to me - means some sort of educated approach. Plus: When your homebrew stuff screws up - it is up on you and no one else.

I believe the @keybrickone approach has a lot in it. We'll see.

I just don't share the notion that an external solution is a mess.

Best
Thorsten

 

     

 

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My only gripe with this is the magnetic switch that toggles the different power profiles. I feel like a tactile switch would have been a better choice... yet I understand if smaller components were not possible.

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Another neat approach would be to run a usb cable from the keybrick to a hollow tender... and there you can put any run of the mill "usb power bank" for rapid refueling, just like refilling water/coal ;)

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Rapido Trains use magnetic switches to turn on/off their HO and N scale passenger cars' lights.  I guess it is useful if you buried the box inside your MOC with no easy physical access to a push button.

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10 hours ago, Toastie said:

Hmmm. That puzzles me. Looking at your device, there is only one port: the USB socket (well and the switch actuated by a magnetic field large enough). So an add-on would attach to the USB port, right. I assume you are using the USB power lines only(?). Which means that your device, when charged with 5V off the USB port can already simultaneously provide power for running the 2I/O hub? Otherwise I don't understand how an add-on can accomplish that with your V1 version.

If so, the add-on would be a "5V power supply", correct?

Oh, I'd beta test whatever so see fit. Already tested the LEGO LiPo 10 years ago - to the extent of that one shrugging me off (at supplying 20(+)V DC charging voltage), just to tell me: Just kidding after 2 days or so.

Best wishes,
Thorsten 

 

Yes, Keybrick support "charging in operation". So the add-on box would rectify and regulate the picked up voltage to 5V, probably on a standard USB port, so a short USB extension cable between that and Keybrick One would be all the wiring required.

10 hours ago, legotownlinz said:

Please do it right and support a wide voltage range directly in Keybrick Two. Any external solution is a mess because

  • it requires extra space
  • it is complicated to connect homebrew stuff
  • it's more likely the Keybrick gets damaged
  • electronics is required for every addon

Extra space; yes, but integrating a wide-supply range (including rectification, the rails/pickup may swap polarity) fails short of space inside Keybrick.

Connecting will be like two wires from the pickup wheels and a USB cable.

As for the two later points: it's shifting cost to those who actually need such a solution, which is probably best for many customers. Having a standard connector on most sides of the whole system (usb output on the addon, micro usb on Keybrick) results in a less probability of people of connecting something unexpected. Plus it could make the addon compatible with other things. Basically anything with some sort of 5V input which can connect with a USB port.

 

8 hours ago, Stux said:

Another neat approach would be to run a usb cable from the keybrick to a hollow tender... and there you can put any run of the mill "usb power bank" for rapid refueling, just like refilling water/coal ;)

Definitely a possibility!

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31 minutes ago, keybrickone said:

Yes, Keybrick support "charging in operation". So the add-on box would rectify and regulate the picked up voltage to 5V, probably on a standard USB port, so a short USB extension cable between that and Keybrick One would be all the wiring required.

Oh man - why didn't you say that in the first place??? Or maybe you did not, and I just missed that.

I mean - this is now a completely different game - depending on the following a bit:

Scenario 1: Let us assume, my 9V tracks are powered with 5V rectified DC and some amperage at hand. Yes, there will be some voltage drops, which will be taken care of in scenario 2. Also, dirty power drop-outs caused by faulty power pickup/track connection may not be tolerated by your device. Have you tested that? Charging with crappy DC voltage? No over-voltage just crappy max. 5V?

Scenario 2: Lets assume, my 9V tracks are powered with 15V DC, as they are now (gives some freedom of powering 4,5V to 12V LEGO stuff + voltage drop). The 15V delivered to TLGs 8878 LiPos is causing no problem whatsoever. They tolerate swift voltage outages etc etc. However, in this case, I'd run the 15 V "DC" track power via a 1A SMD bridge rectifier into a 7805 or any other smaller derivative, into a decent capacitor, lets say 100+ microF, which would take away any sudden voltage drop-outs. Would your device tolerate that?   

Let's assume the KB1 does tolerate crappy DC charging voltages (never exceeding 5V though): Then we have it - we have the thing we were looking for: Either with 5V track voltage (not so good) or with 12(+) V and a simple little add-on. 

Wow.

Best
Thorsten 

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Just now, Toastie said:

Oh man - why didn't you say that in the first place??? Or maybe you did not, and I just missed that.

I mean - this is now a completely different game - depending on the following a bit:

Scenario 1: Let us assume, my 9V tracks are powered with 5V rectified DC and some amperage at hand. Yes, there will be some voltage drops, which will be taken care of in scenario 2. Also, dirty power drop-outs caused by faulty power pickup/track connection may not be tolerated by your device. Have you tested that? Charging with crappy DC voltage? No over-voltage just crappy max. 5V?

Scenario 2: Lets assume, my 9V tracks are powered with 15V DC, as they are now (gives some freedom of powering 4,5V to 12V LEGO stuff + voltage drop). The 15V delivered to TLGs 8878 LiPos is causing no problem whatsoever. They tolerate swift voltage outages etc etc. However, in this case, I'd run the 15 V "DC" track power via a 1A SMD bridge rectifier into a 7805 or any other smaller derivative, into a decent capacitor, lets say 100+ microF, which would take away any sudden voltage drop-outs. Would your device tolerate that?   

Let's assume the KB1 does tolerate crappy DC charging voltages (never exceeding 5V though): Then we have it - we have the thing we were looking for: Either with 5V track voltage (not so good) or with 12(+) V and a simple little add-on. 

Wow.

Best
Thorsten 

There is some decoupling in Keybrick itself, but it performs poorly with "dirty" input. The least you would have to do rectification plus is some hard clamping (TVS diodes at 6V or so) to make sure the inductance induced spikes of the bad contacts are not getting to the port (at a 5V track voltage I would expect up to 13V spikes) and a good bunch of decoupling.
The external add-on I have in mind is basically a wide-range buck-boost regulator which has this kind of protection and provides a clean 5V out by regulating dirty stuff away. I have a regulator on hand that would be nice as it would work from 3-30V. Just a matter of building everything around it into a small-ish package  and properly testing it.

The pure electronics for this should be doable within a 10€ sales price budget (rough estimate). Cost of a 3d printed case is hard to estimate before I know the size of it.

 

P.S.: I just searched for it and indeed I managed to forget to talk about the "in operations charging" on Eurobricks. My bad. We posted an update on Kickstarter a while back and wrote about that on many different occasions. Basically, we managed to contain conducted spurs from the hub within keybrick pretty well in its inital state already, and the single remaining frequency could be filtered by adding an addition 100nF cap on a previously unpopulated spot on the PCB. So it was a matter of a few cents of hardware changes and a few hours of measuring.

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14 hours ago, Stux said:

Another neat approach would be to run a usb cable from the keybrick to a hollow tender... and there you can put any run of the mill "usb power bank" for rapid refueling, just like refilling water/coal ;)

Yes, this would be (is) a killer feature. Would it be possible to make a cheaper non-battery KB that passes power through from a usb power bank to the the PUP hub?

 

Now on a different question, is the power boost mode (specifically using a higher voltage) at risk of degrading the motors quicker?

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1 hour ago, zephyr1934 said:

Yes, this would be (is) a killer feature. Would it be possible to make a cheaper non-battery KB that passes power through from a usb power bank to the the PUP hub?

That's potentially tricky. The hub can technically draw up to 1.5A from the battery pack. If we were to step up the 5V from the USB to about 9V that would require the USB supply to bear a load of 9v*1.5A = 13.5W which is about 3A at 5V considering a 90% conversion efficiency. Doable but not for many run-off-the-mill power banks.

1 hour ago, zephyr1934 said:

Now on a different question, is the power boost mode (specifically using a higher voltage) at risk of degrading the motors quicker?

The motors are fairly well protected for one (they have their own PTC fuse which will cut power if they stall for too long). And brushed DC motors are very reliable beasts. You can drive them well above (twice for example) their nominal voltage for a long as the load scales. 

Realistically the few 100mV more vs. Brand new Alkalines isn't going to hurt.

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11 hours ago, Toastie said:

Scenario 1: Let us assume, my 9V tracks are powered with 5V rectified DC and some amperage at hand. Yes, there will be some voltage drops, which will be taken care of in scenario 2. Also, dirty power drop-outs caused by faulty power pickup/track connection may not be tolerated by your device. Have you tested that? Charging with crappy DC voltage? No over-voltage just crappy max. 5V?

And there it goes...

That's what I meant when I suggested an universal input that accepts any voltage.

Reducing the voltage to 5V on the tracks is not enough, you need the rectifier on the train and not in the power supply because the polarity changes when you turn around the train. This either destroys the Keybrick One or it won't charge.

12 hours ago, keybrickone said:

As for the two later points: it's shifting cost to those who actually need such a solution, which is probably best for many customers.

And what is the use-case where you don't need these add-ons?

I'd say that most of the trains hubs are used in trains and there you need some way to charge without disassembling the train. That's what 95% of your customers need.

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1 minute ago, legotownlinz said:

And there it goes...

But a bridge rectifier and two capacitors along with a voltage regulator ("the universal input") is very far, far away from any "mess".

Of course, it won't charge or may even go rip without. As would your cell phone do.

Best
Thorsten

 

 

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16 minutes ago, Toastie said:

But a bridge rectifier and two capacitors along with a voltage regulator ("the universal input") is very far, far away from any "mess".

Indeed. But you need space for the rectifier and the capacitors in the wheel set or you need extra space somewhere else which would require a redesign of most trains. That should be possible for most trains, but it is an obstacle that holds possible customers off from buying the product.

I get the point that the company behind Keybrick One is not excited about the idea of vastly redesigning their product and I'm fine if they don't do it. I just wanted to say what features would make me buy it. And this is definitely convenient recharging of my trains without removing any parts. If I have to disassemble anything, then I can stick to Lego's hub, which allows me to just replace the batteries and run the train again without waiting until the batteries are charged.

Edited by legotownlinz

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I’m fairly certain the idea is to have a brick which converts from track power, via a pickup, to usb on the train. 
 

this would allow a pup train to charge whenever it’s on powered tracks. 
 

and as I see it, that allows a pup train to run on everything, which seems like the holy grail to me. 

I can’t see how it would be bigger than an existing pf or brick. I’d hope it were much smaller.

I wonder what percentage of running time a train would need on powered tracks to run indefinitely. 

Edited by Stux

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Just now, Stux said:

I’m fairly certain the idea is to have a brick which converts from track power, via a pickup, to usb on the train

Agreed, that's needed. But the pickup is not available, so the product is incomplete. Like a car sold without wheels...

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