? Power for trains

[knotian]

This is just a strange idea I had from reading the posts on power pickup in the forum.

There are some lights that are wireless, picking up their power from the base of the structure. ( i-Brix ) This, I imagine, is like the wireless charging available for cell phones, inthat an induced current is picked up from the antenna and applied to the battery.

For you technical people - what would be the possibilities on using that concept for trains? I realize that the power drain is too large for direct drive of a motor. But what about a battery with a charging coil permanently attached and an antenna wire in the track base?

Just food for thought from an easily distracted mind

[ColletArrow]

Hmm.

How about, rather than having the train constantly charging, what if the charger was in a station or siding, such that a train could be charged whilst stationery and move off when full? You could use some train control software to detect low batteries, and send the train to an available charging station and until it's ready to move off...

I'm not sure having the antenna all around the tracks is plausible, but several charging ports might work. The motion of the train may cause the current induction not to work sufficiently, I'm not entirely sure of the details of how these things work.

[MAB]

48 minutes ago, knotian said:

 But what about a battery with a charging coil permanently attached and an antenna wire in the track base?

 

 

I would imagine that this would make track prohibitively expensive and it is probably not that great a gain - there is no weight advantage for example - the only real gain is not having to recharge if it works and for most people I doubt that matters compared to the cost of the track.

I also doubt you could charge the battery at a fast enough rate compared to the rate of drain when the train is moving. Remember those LEDs require very low power.

[knotian]

Good points

A siding with the charging coil should work and cheaper than wiring all the track.

[mattmarsden]

Any suggestion on what charging coil would be suitable?

[HiFish]

If you build a dedicated charging siding it might be easier to use a single classic 9v rail for this, combined with a custom pickup wheelset as described here:

Alternatively you could use a broken 9V-Motor-Bogey which as a pure power-pickup after you remove the motor.

[Toastie]

I completely agree with HiFish.

Get some 9V track, power that up and use "power pickup means" (custom devices, as mentioned by HiFish, modified 9V train motors, entirely sacrificed 9V train motors) to recharge your "batteries".

You may want to check here, but this is only one way to do it in a rather straight forward manner.

Regards,
Thorsten 

 

[dr_spock]

Wireless power transmission is not very efficient.   The magnetic field could be an issue for people with heart pace maker implants if they get too close.

 

[Duq]

The system you're thinking of exists already. Bombardier call it 'Primove'. It's expensive to build but you can see the advantages in the real world: no unsightly and possible dangerous overhead cables.

In theory it should be possible to build this at a smaller scale but it won't be easy...

http://primove.bombardier.com/applications/tram.html

[JopieK]

@mattmarsden You probably need something that is about 10V. A coil is already AC, I just finished a non-LEGO project where we charge a 5V battery system. I noticed that depending on the voltage I get a smaller or larger distance between the coils that it charges with. This is the one I use, probably it is better to use a slightly higher voltage for the LEGO adapter. You should be able to drop the receiver print since it will convert the AC in DC again and the LEGO LiPo likes AC. These are the coils we successfully use for our project: https://aliexpress.com/item/5V-2A-Wireless-Charging-Cellphone-Charger-Module-Power-Supply-Coil-DIY-Board-For-Smart-Mobile-Phone/32805677637.html?spm=a2g0s.9042311.0.0.l3gs5F