Modeltrainman Posted July 31 Posted July 31 With the news that FX Bricks cables are coming, does the possibility exist of powering an unmodded Powered Up from my 9v track? Ideally,I'd like to leave everything unmodified, and plug in a cable. Could that be possible, if not yet? Quote
Toastie Posted July 31 Posted July 31 (edited) 28 minutes ago, Modeltrainman said: With the news that FX Bricks cables are coming, does the possibility exist of powering an unmodded Powered Up from my 9v track? Ideally,I'd like to leave everything unmodified, and plug in a cable. Could that be possible, if not yet? Yes. Plugging in maybe difficult, though, as the PUp hub wants 6 x 1.5V batteries. And “upstream” of the PUp hub's power feed, some additional gear is required, at least this is my experience, others may know better. You may want to take a look at this pinned topic: The PUp hub likes nicely conditioned 7 … 9V, as, e.g., provided by rechargeable or alkaline batteries. The “condition” of 9V track power depends on a) your track power supply and b) your power pickups. What I have done (there are several posts here on EB, I am happy to digging them up, let me know) - and this is the most expensive, but really fail-safe approach: Power pickup = burnt or modified 9V train motor. The nice things about this is that the wheels are usually in good contact with the rails, as they are sort of “spring-loaded”. I strongly recommend putting in a bridge rectifier to avoid any polarity issues. Power supply = the rechargeable PowerFunctions battery box 8878. If you are not afraid of the dark side, they sell for $10. If you are, you are looking at +$80. You feed the power pickup terminal to the charging socket of 8878. The latter accepts any voltage between <9V and 18V; even if the power feed from the rails is noisy - 8878 simply does not care. You feed the PF 9V output terminal to the PUp hub with a custom cable you have to fabricate. As a result, your train can run “forever” provided it is always on 9V track; can run over plastic track, as the battery box then still feeds the PUp hub; and simply parking it on 9V track will fill up the battery box to full, when not in use. As said, there are some references, let me know if you need these. All the best Thorsten Edited July 31 by Toastie Quote
Modeltrainman Posted July 31 Author Posted July 31 2 minutes ago, Toastie said: Yes. Plugging in maybe difficult, though, as the PUp hub wants 6 x 1.5V batteries. And “upstream” of the PUp hub's power feed, some additional gear is required, at least this is my experience, others may know better. You may want to take a look at this pinned topic: The PUp hub likes nicely conditioned 7 … 9V, as, e.g., provided by rechargeable or alkaline batteries. The “condition” of 9V track power depends on a) your track power supply and b) your power pickups. What I have done (there are several posts here on EB, I am happy to digging them up, let me know) - and this is the most expensive, but really fail-safe approach: Power pickup = burnt or modified 9V train motor. The nice things about this is that the wheels are usually in good contact with the rails, as they are sort of “spring-loaded”. I strongly recommend putting in a bridge rectifier to avoid any polarity issues. Power supply = the rechargeable PowerFunctions battery box 8878. If you are not afraid of the dark side, they sell for $10. If you are, you are looking at +$80. You feed the power pickup terminal to the charging socket of 8878. The latter accepts any voltage between <9V and 18V; even if the power feed from the rails is noisy - 8878 simply does not care. You feed the PF 9V output terminal to the PUp hub with a custom cable you have to fabricate. As a result, your train can run “forever” provided it is always on 9V track; can run over plastic track, as the battery box then still feeds the PUp hub; and simply parking it on 9V track will fill up the battery box to full, when not in use. As said, there are some references, let me know if you need these. All the best Thorsten I'm sorry, sir, I didn't understand any of that, save for the implied 'It's possible, but...' I'm sorry if I didn't phrase it better. Basically, 'once FXBricks stuff comes out, can I plug a powered Up to 9V cable to their wheelset, other end into the A port on a PU hub and power the hub via track?' is my question. Quote
XG BC Posted July 31 Posted July 31 no you cannot, since you cant input power into the hub via that port. thats only a power output. it still wont be that simple. either go wheelset -> powerfunctions rechargable battery box -> powered up hub battery compartment. or go wheelset -> big capacitor and powered up hub (the capacitor is just to make the track power more stable, you might not even need it) Quote
dr_spock Posted July 31 Posted July 31 You could power the PU train motor off the 9V tracks. You would need a power pick up wheel set. Connect the PU train motor cable to the pickup. If you make your own female PU adapter, pin 1 & 2 are the power control lines. Powering the PU hub off the 9V track could be done. You would still need a power pick up wheel set. You can not plug into the A port. You would need an adapter to take the place of the batteries holder. Probably have to set the 9V train controller to full 9V output. Also you'll need the +/- polarity to be correct or have some fancy diode bridge. Quote
XG BC Posted July 31 Posted July 31 by diode bridge you mean a bridge rectifier. these are available in one package, preassembled, you just need to connect the ~ inputs to the wheelset and the + and - output to your hub. something like this: https://www.digikey.com/en/products/detail/vishay-general-semiconductor-diodes-division/W04G-E4-51/754892 Quote
Modeltrainman Posted July 31 Author Posted July 31 Thank you, all! Hopefully, someone could invent a way as ditching batteries, but still using the Hub'd be great! Quote
dr_spock Posted July 31 Posted July 31 Something like this could be 3D printed to make an adapter to feed 9V track power to the PU hub if you don't want to solder wires directly to the PU hub circuit board. https://www.thingiverse.com/thing:6858192 Quote
Modeltrainman Posted August 1 Author Posted August 1 Sadly, no 3D printer. I wish we knew why LEGO decided electricity was bad. Traditional model railroading has DCC. Quote
XG BC Posted August 1 Posted August 1 it was too expensive to make, and lego was struggling financially at that time. all plastic was cheaper to make, and thus here we are. i dont like it either (hence why i still use 9v with custom power pickups and copper tape on plastic track) Quote
L-Gauger Posted August 1 Posted August 1 @Modeltrainman, you make an interesting point regarding conventional model railroad power sources compared to Lego train power sources. As someone who is active with both conventional (HO and N scale) trains and Lego trains, I've never fully (notice I did say fully) understood why the battery-powered solutions offered by Lego are disliked by so many in the Lego train hobby. It's true that conventional model railroads usually use track power, but for the last eight years or so battery-powered, remote-controlled trains have been heralded by conventional model railroaders as the wave of the future. Meanwhile, us Lego train fans have had battery power since the mid-2000s, but many complain and wish for the days of track power. I can't deny the advantages of track power, but I also know what a pain it is to keep the track clean on my N and HO scale layouts. I relish my L gauge trains because, even though they do require battery changes, spotty electrical pickup is never an issue. That's not to say battery power is the only way (obviously it isn't, and Lego makes their battery boxes way too big to fit in little switchers/shunters,) but I do think that we Lego model railroaders should count our blessings in that we have both battery power (from Lego and 3rd party) and track power (from old 12v, 9v, and Fx Track/Fx Power.) Traditional model railroaders have to build their battery systems from scratch, and I'm grateful we don't have to. Quote
XG BC Posted August 1 Posted August 1 30 minutes ago, L-Gauger said: As someone who is active with both conventional (HO and N scale) trains and Lego trains, I've never fully (notice I did say fully) understood why the battery-powered solutions offered by Lego are disliked by so many in the Lego train hobby. I personally dislike it because batteries need to be changed, charged etc, and take up space (although with cirquitcubes the space thing is kind of a moot point, atleast for normal gauge models). track power is just more flexible with models, especially if you use custom pickups from model railroad companies like märklin. regarding contact: lenz has an awesome solution if you use DCC. i currently dont, but my dad does, he is into h0 scale model trains, he has an h0 scale model köf II from that company. It has a supercap that powers the decoder through dead spots while still remaining controllable (i guess through capacitive coupling). its super wild, here is a Video (not my dad): it can literally drive over a piece of paper and keep going. of course this is more involved than just plugging a hub in and stuff, but its still incredibly cool. Quote
dr_spock Posted August 2 Posted August 2 20 hours ago, Modeltrainman said: Sadly, no 3D printer. I wish we knew why LEGO decided electricity was bad. Traditional model railroading has DCC. There was probably some children safety and liability lawyers aspect to going away from AC adapters to batteries. The newer battery boxes now have screws to keep closed. G-scale garden railways modelers also make use of battery powered trains if they are not keen on outdoor track maintenance and corrosion related electrical issues. Quote
Lok24 Posted August 2 Posted August 2 (edited) How do you control two or more 9V-Trains on the same track / layout? How would you control a train via BT? Since 40 years the conventional model railroads use digital systems like DCC for these purposes But there you need some central intelligence and much more power. Edited August 2 by Lok24 Quote
XG BC Posted August 2 Posted August 2 depends on what you want to do. old laptop or pc power supplies are fairly cheap and can deliver a lot of power, and much more power? not really. its just supplied from one supply vs from various batteries inside the trains. the power draw is the same. you can even build your own DCC encoder with an arduino nowadays. its no longer wildly expensive. Quote
Toastie Posted August 2 Posted August 2 True, today you can do anything - don't talk about the better olden days ... I guess, this discussion needs some well-defined boundary conditions, doesn't it? All 9V track, only plastic or mixed tracks? Of course, DCC requires all conductive tracks, battery operation none at all. Do you want “absolutely” secure remote control? E.g., for shows? BT or BLE may seriously suffer ... Do you want all layout freedom, e.g., "fully" powered wyes? Which requires insulation ... Are you purist? Only LEGO gear allowed? Once that is into the clear, planning may begin. For example, my case is: Layout only in my attic; 433 MHz RF is cool, BT is, BLE is - as my neighbors don't do any of that ... 9V track all over the place, 12V as well, and 4.5V and ... RC/PF = all plastic ... Wyes? Absolutely. It is "tight" up there ... My approach: Full wireless control. 433 MHz RF, modded into PF; 2.4 GHz BLE (PoweredUp) Trains are all rechargeable batteries operated - either via discrete NiMH (1.2V) stacks, or LiPo's (8878). Some have an RCX 1.0 on board ... NiMH's are trickle charged, the 8878's are directly fed by power pickups (= cannibalized or modified 9V motors) As a result, all trains can run over lengthy stretches of plastic tracks and recover on 9V tracks. Super caps may not serve that purpose, it depends on the "lost power time", of course. Track voltage is 15V DC - from an "old" laptop power supply - it can supply insane amounts of current. And 15V is nice, any 78XX with XX<=12V will give you all flexibility to power 4.5 (5) V, 9V, and 12V trains. Oh yes, this is total fun! All the best, and may the power be with you guys! Thorsten Quote
CaL Posted August 2 Posted August 2 Hi, maybe this product called “Keybrick One” or the “Keybrick One Lite” could be an alternative: https://keybrick.one Quote
dr_spock Posted August 3 Posted August 3 The OP wants to power the PU hubs off train track power instead of batteries. It could be done by supplying the metal tracks with 9V AC power. Install a power pick up wheel set on the train. Use a bridge rectifier to convert the AC to DC for the PU hub. Connect the output to the terminals inside the PU hub (and pray for no smoke). Use the PU remote or PU App to control the train. (This setup won't be able to run old 9V trains on the same tracks.) Quote
Toastie Posted August 3 Posted August 3 5 hours ago, dr_spock said: by supplying the metal tracks with 9V AC You can also use DC (e.g., 15V), run that through a bridge rectifier with both "~" inputs connected to the pickups (causing a voltage drop of about 1 V). This takes care of polarity changes caused by reversing loops). Then connect the +/- terminals of the rectifier to a 7809 regulator, and then feed the PUp hub from the 9V output of the regulator. Experience shows though that voltage "outages" caused by insulation for reversing loops/polarity changes = 1 plastic track piece, or sometimes bad contact between the pickups and the hub do lead to malfunctions, particularly regarding the PoweredUp hubs. Some sort of buffer (caps, supercaps, etc.) are thus required. Best Thorsten Quote
Lok24 Posted August 3 Posted August 3 6 hours ago, dr_spock said: The OP wants to power the PU hubs off train track power instead of batteries. Yes, I understood, I referred to the part why LEGO might have replaced 9V with PU. esp. in comparison to model railroad. Quote
zephyr1934 Posted August 5 Posted August 5 On 8/1/2025 at 12:50 PM, XG BC said: it was too expensive to make, and lego was struggling financially at that time. all plastic was cheaper to make, and thus here we are. That was why they stopped. Then as Lego clawed out of the financial struggles they got serious about figuring out the marginal cost of everything. So now that Lego is thriving there's no way they'll go back to expensive metal track. Anyways, like so many others here, I like having the small power pickup motor so that you do not need to make room in the engine for a battery or receiver. But I also like having a battery on board so that I do not need to worry about cleaning tracks. Or for that matter, the accumulated voltage drop across many track joints. Even if R is small for a track joint, v=iR can become significant if you have a few dozen track joints between the train and the power drop. Quote
L-Gauger Posted August 5 Posted August 5 On 8/1/2025 at 5:27 PM, XG BC said: I personally dislike it because batteries need to be changed, charged etc, and take up space I can understand that. The traditional model railroaders I've seen embrace battery power have either A) used a section of powered track on the layout as a "charging pad" for locomotives, or B) hidden a little charging plug on the model and leave it plugged in to charge between operating sessions. The whole AAA battery paradigm of Lego trains is a huge disadvantage compared to that. On that note, I think a great product for a 3rd party manufacturer to make would be a 9V or PF compatible battery box, external dimensions 2x4x3 bricks tall, that holds one 9-volt battery. Bonus points if they figured out how to mold the housing to permit no-tools-required battery changes. On 8/1/2025 at 5:27 PM, XG BC said: regarding contact: lenz has an awesome solution if you use DCC. i currently dont, but my dad does, he is into h0 scale model trains, he has an h0 scale model köf II from that company. My DCC system is from Bachmann, but was developed in partnership with Lenz, so I have a bit of experience with their products. Theirs (and Bachmann's) E-Z Command system is really easy to use and doesn't break the bank. I don't own any locomotive with keep-alive capacitors, but those are crazy cool! Definitely a good compromise to mix the advantages of battery and track power. With all this talk of DCC, did you ever see the video where one of the guys at Model Railroader replaced the IR receiver on his Lego Maersk locomotive with a Bluetooth DCC sound decoder? https://www.trains.com/vid/toytrains/series/lego-trains/install-a-blunami-decoder-in-a-lego-locomotive/ On 8/1/2025 at 10:05 PM, dr_spock said: G-scale garden railways modelers also make use of battery powered trains if they are not keen on outdoor track maintenance and corrosion related electrical issues. True, that's the most popular scale for battery power. I've also seen some modelers in the O and HO scales embrace battery power too. In my experience, finding the space for the batteries in a Lego locomotive does depend heavily on the scale you choose. My 1:38 scale (10-wide) 2-6-0, though a small locomotive by U.S. standards, has plenty of room for the big Technic AA battery box. On the other hand, building the same locomotive in 1:48 (8-wide) or 1:64 (6-wide) makes track power a much more compelling proposition. 18 hours ago, zephyr1934 said: Anyways, like so many others here, I like having the small power pickup motor so that you do not need to make room in the engine for a battery or receiver. But I also like having a battery on board so that I do not need to worry about cleaning tracks. Or for that matter, the accumulated voltage drop across many track joints. Even if R is small for a track joint, v=iR can become significant if you have a few dozen track joints between the train and the power drop. I think you've summed it up pretty well here @zephyr1934. That's a very good and fair comparison of track vs. battery power as it pertains to Lego trains. Quote
Lok24 Posted August 6 Posted August 6 10 hours ago, L-Gauger said: A) used a section of powered track on the layout as a "charging pad" for locomotives, or B) hidden a little charging plug on the model and leave it plugged in to charge between operating sessions. So you can't use them permanently. A huge disadvantage. And if you don't use WLAN DCC requires metal rails for transfer of information. And the PU-Hubs have separate battery holders. Quote
L-Gauger Posted August 7 Posted August 7 On 8/6/2025 at 3:34 AM, Lok24 said: So you can't use them permanently. A huge disadvantage. A disadvantage to be sure, but the model railroaders I've seen get a battery life of 2-3 hours on a charge, and they incorporate the re-charging as a "re-fueling" procure in operation. The most creative solution I've seen is a steam-era modeler, can't remember if he modeled in On30, HO, or HOn3, but he put the charging port in the water tank of his steam engines, and then disguised his battery charger as the water tower at the engine terminal of his layout. Quote
lumanaire Posted August 16 Posted August 16 (edited) I got a custom cable made from PV productions that does just this it will power a city powered up hub or a technic hub using a 9v cable it works both directly on the regulator or through the contacts on a 9v train motor to power the hub they have a variety of adapters but if you want something specific you can contact them and they'll make it for you Edited August 16 by lumanaire Quote
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