Model train electronics (2023 Update)

Or you can skip power transmission thru the rails altogether and have on-board batteries with radio control:

can have multiple locomotives operate simultaneously on the same track.

That's what I was thinking. It would be more like a real train having to stop at a filling point to get fuel. The power connection could be wireless, or it could emulate a fuel hose and be plugged into the fuel tank on the engine. Charge up the battery and it's ready for another trip. I guess you need someplace to put the batteries. Diesel trains don't have hopper cars anymore. They don't even have cabooses. The caboose is a red light fastened to the last car. I think it monitors pressure in the air hose.

Is there space in the locomotive for a battery or two? The engine control could be RF which could be very small, a single 8 pin MCU plus the RF receiver which can be a single transistor and a coil I believe. They probably already have the remote RF and MCU unit. I expect the only real issue will be where to put the battery.

On Friday, 31 December 2021 at 09:01:01 UTC-8, snipped-for-privacy@gmail.com wrote: ...

... The commercial units are a bit more sophisticated than that with full superhet 2.4GHz receivers and an H-bridge to operate the motor. The smallest are about 1cm square and about 2mm thick. Additional output channels are often available for controlling lights etc.

The battery is a space issue in the smaller scales such but the smallest single cell at a bit larger than the receiver can often be squeezed in.

Multiple trains can be run on the same track without resorting to this approach using Digital Command Control (DCC) where the track is fed a coded signal that is used to provide both power and data.

kw

[...]

Where does it say that these are superhets?

Jeroen Belleman

On Friday, 31 December 2021 at 09:55:35 UTC-8, Jeroen Belleman wrote: ...

... These days nobody would implement anything other than a superhet in an IC. The requirements for frequency accuracy and emissions mean that super-regenerative receivers are not appropriate. The receivers do typically use either zero IF with I/Q demodulation or a low IF in the couple of hundred kHz region as that can avoid the need for external LC or ceramic filters.

I think this is the data sheet for the receivers I linked to:

kw

Ah, I see the 12MHz crystal in the pictures now. OK, superhets.

Jeroen Belleman

The link provided details all of this. The batteries are rechargeable lithium's and recharging can be done on any electrified portion of the track. Control is by RF, again shown in the link. It is more expensive than the old way but eliminates a lot of problems. And if you are a serious hobbyist the cost is irrelevant.

The link is of a design using modules rather than an integrated design. But they manage to cram it into an HO gauge so I guess it's not all that large. It would seem they charge through the rails? I guess you can do that with a stationary unit and not have the problem with the tarnish impacting the connection.

They are no different from your Tesla - it doesn't charge while you're driving, either.

Your reading comprehension is pretty poor, eh? That is in no way responsive to what I was saying.

There are some electric ones with internal batteries to smooth out any dead spots on moveable tracks too.

Radio control is used on some smaller scale steam powered locos.

Models too small to actually pull a bogey with a man on it. It is a cottage industry in the UK making controllers for this narrow gauge. They are small scale live steam with a spirit burner boiler.

Live steam enthusiasts tend to have limited electronics skills.

Not following. What exactly is "this" that doesn't work? What specifically won't work in small gauge trainsets?

Maybe on newer equipment. I worked for the railroad around 1980. It wasn't much more than a light then.

Did you not see the web page someone posted a link to? The complete (bulky) electronics and battery fit inside an HO gauge engine.

I don't know why a 1/8 inch (3 mm) "phone" jack is widely used in earphone and mic apps in laptops, and phones. That's not a market where they are babied. Here's a link to many sizes of connectors.

The circuit board(s) can be made much smaller. They use multiple boards to reduce the design work, but an MCU can be used to consolidate some of the functions making the electronics much smaller.

On Monday, 3 January 2022 at 18:21:06 UTC-8, snipped-for-privacy@gmail.com wrote: ...

...

The receivers I linked to in a previous post are small (~1cm sq). They can be fitted even into N-gauge (9mm track gauge) and similar (009, HoN30...).

The MCU and a frequency synthesized receiver all fit into one device that needs very few external components.

The complete receiver:

Here is a video showing it being installed including battery in an 009 locomotive.

kw