Magnets and Electricity.. That’s a Power Couple

Today I’m bringing you some sweet new prototype technology from our good friends at 4DBrix. Tom Lowa was at Brickworld recently to show off something he’s been cooking up, and I have to say, it’s a pretty sweet idea. I’ve been emailing Tom about the concept and here is the information they gave me.

4DBrix has engineered a way to transmit power via the magnetic couplings on train cars. A short video is posted below:

It’s a pretty ingenious idea. For those that enjoy building passenger trains with detailed interiors (and lights) this is a great way to eliminate those ugly wires between the ends of cars. It also eliminates the need for bulky connectors between cars, which can be difficult to plug in and are also unsightly.

The prototype you see in the video is similar to this:

The idea is that you could mount this on one of the newer train couplers (the ones with studs on the top and bottom) and the magnets contact each other when you couple two cars together, forming a circuit. This is ideal for LEDs in passenger cars.

Tom has also been considering adding a third (and maybe, but not likely) a fourth magnet in order for a car to send and receive data. 

Here, the four magnets are power, ground, read, write.

Tom tells me that the 4-magnet connector is a little bulky (I agree) and that the four magnets do not always make contact.

After this, Tom started looking into 3-magnet designs (no photos of these yet). Here, there would still be power and ground lines, but only one communication line, so the data could be sent in either direction, but only one way at a time, and the speed is somewhat limited. That said, if there was to be a data connection between to cars, I don’t think the amount of communication would be too great for this system to handle.

Three connectors would actually work better than four in this case. When you reverse the direction of a car in a train, you change the order of connection with the magnets. In a four magnet coupling, the power lines could be solved with a bridge rectifier, which Andrew Mollamnn touched on in his article about supercapacitors, but there is no solution for the data lines. Using three magnets, and putting the data line in the middle, then the issue resolves itself.

In the end, Tom told me he is mostly considering this system:

  • “magnetic couplings with a ‘3-wire’ connection: ground – data – power.
  • the data line can be switched between read and write.
  • the devices in the wagon are ‘smart’.  They all have a unique ID and when the controller sends an instruction it includes the ID and only the device with the corresponding ID responds.  That allows you to, for example, switch on a particular LED in a particular car.
  • this system is modular / expandable: you can add as many devices as you want.”

Tests have been conducted with “smart” devices with small micro controllers, which have been successful.

Overall, I’m really excited about this idea. I enjoy building passenger cars, which are even cooler with an interior. This connector adds ease to adding lights in those cars, which is a big plus for me.

4DBrix also says they are looking into integrating this system to work with a remote decoupling system.

The idea here is to use a servo motor mounted on the right to push the two chocks together, blocking the wheels of one car while the rest of the train is pulled forward by the locomotive.

I’m excited about this, and I’m reminded of the classic 12V system decoupler track, which was one of my favorite features of the old 12-volt era.

If possible and reliable, this would be an amazing feature to have in a yard, on sidings, or anywhere else you may want to uncouple some cars.

Even though it’s still in the testing and design stage, this concept shows a lot of potential for implementation into models.

Be sure to check out 4DBrix for more cool stuff.

One thought on “Magnets and Electricity.. That’s a Power Couple”

  1. Thank you for opening for comments 🙂 As I mentioned in private message, in my opinion first of all issue of magnetic poles should be solved. 2 extra magnets work best if they have same values of magnetic poles. They set main buffer magnet in best position, they build stronger coupling between cars but on the other hand, they require cars to be attached one to another always in same direction. Different poles in extra magnets may cause main magnet in buffer not to be placed in optimal way. Another configuration with 3 extra magnets will definitely require same direction in cars no matter of pole setup (—, – – +, – + +, +++ , – + -, + – +). 4 magnets solves this problems but then it makes coupler really bulky. Even 2 magnets can make some troubles on R40 switches… I like solution proposed by BrickStuff (modified main buffer magnet with extra line going through center of magnet) but I guess it would limit number of electric lines to 2. I’m pretty excited and curious about system that 4DBrix is working on (ID per segement, etc). So far I’m using own (analog) solution


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