Route of electrics from the tracks to the motor

Started by Swadieram, December 08, 2019, 02:11:09 PM

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Swadieram

Hi all im very new to railways

I'm guessing the wheels  transfer electricity   from the track to the  motor!
Excuse my ignorance is there insulated bearings between the wheels and the axel ?
Or is the axel insulated thanks

Ditape

Unfortunately there is no simple answer to your question, the power pick-up is normally via the wheels but how the wheels are isolated varies from make to make and sometimes batch to batch.
Diane Tape



ntpntpntp

#2
As @Ditape  days, there are different designs used for transferring the power from  wheels to the motor.

Is there a particular model you are curious about?  Is it for the purposes of understanding how to service locos, or simply to understand how these models work?

The traditional method is to use thin wiper contacts on the backs of the wheels, with the wheels insulated from the axle.  This may be only on one side, with the other side having a non-insulated wheel so that power transfers via the axle to the chassis block.

Another method is to use insulated "half-axles" with wheels, and the power transmitted either through the axles to the chassis block or through the pinpoint ends of the axles to metal "axle-box" pickups.   Where the power transfer is through the axle shafts, you'll find the entire chassis block is electrically and physically "split" down the middle.

With bogie diesel and electric locos you also have the problem of transferring power from the swivelling bogies to the main chassis block. That may be via wiper contacts onto "pads" or directly onto the metal chassis, or it may use thin flexible wire soldered to a circuit board.

Power then goes from the circuit board or split chassis block to the motor brushes, again either by contact strips or soldered wires.

To complicate things further, modern "DCC ready" locos which have a socket to take a decoder (an electronic module for digital control of a loco) will route the power via this socket not directly to the motor. If a DCC decoder is NOT fitted, then a "blanking plate" is required in the socket which links the wheel pickups to the motor.
Nick.   2021 celebrating the 25th anniversary of "Königshafen" exhibition layout!
https://www.ngaugeforum.co.uk/SMFN/index.php?topic=50050.0

crewearpley40

#3
If contemplating model railway building, why not read : ngaugeforum.co.uk/SMFN/intopic=35556.msg416493#msg416493 written by mick newportnobby or ngaugeforum.co.uk/SMFN/index.php?topic=35556.msg416493#msg416493

Lawrence

Quote from: ntpntpntp on December 08, 2019, 02:35:42 PM
As @Ditape  days, there are different designs used for transferring the power from  wheels to the motor.

Is there a particular model you are curious about?  Is it for the purposes of understanding how to service locos, or simply to understand how these models work?

The traditional method is to use thin wiper contacts on the backs of the wheels, with the wheels insulated from the axle.  This may be only on one side, with the other side having a non-insulated wheel so that power transfers via the axle to the chassis block.

Another method is to use insulated "half-axles" with wheels, and the power transmitted either through the axles to the chassis block or through the pinpoint ends of the axles to metal "axle-box" pickups.   Where the power transfer is through the axle shafts, you'll find the entire chassis block is electrically and physically "split" down the middle.

With bogie diesel and electric locos you also have the problem of transferring power from the swivelling bogies to the main chassis block. That may be via wiper contacts onto "pads" or directly onto the metal chassis, or it may use thin flexible wire soldered to a circuit board.

Power then goes from the circuit board or split chassis block to the motor brushes, again either by contact strips or soldered wires.

To complicate things further, modern "DCC ready" locos which have a socket to take a decoder (an electronic module for digital control of a loco) will route the power via this socket not directly to the motor. If a DCC decoder is NOT fitted, then a "blanking plate" is required in the socket which links the wheel pickups to the motor.

Wot e said :thumbsup:

Swadieram

Thanks

I'm going down the dcc route and wanted to understand how it the electricity flows

ntpntpntp

#6
Quote from: Swadieram on December 08, 2019, 05:10:24 PM
Thanks

I'm going down the dcc route and wanted to understand how it the electricity flows

OK, so for both DC or DCC the basic flow into the mechanism is the same, but as I mentioned previously with DCC the motor and lights are no longer directly connected to the power. With DCC, the decoder receives the power, rectifies it and uses it to power a microprocessor. The processor is programmed to look for a valid DCC signal, and look for commands sent to its programmed address. It will act according to those commands, driving the motor in the required direction and speed, switching lights and sounds on or off etc.

Most DCC decoders also have the ability to run the loco on plain DC if the microprocessor receives power but doesn't detect DCC signals at all. (That capability can be turned off by programming).

What you should definitely avoid is running a loco without a decoder on a DCC layout, even if the system says you can! In simple terms it works by artificially "bending" the DCC power in the track, but the motor in the non-DCC loco is under power continuously even when not moving.  It's extremely bad for the small motors of N gauge locos and can kill some types of motor very rapidly.  Larger scale motors can cope better, but to be honest it's something which was built into DCC systems in the early days and has fallen out of favour nowadays.
Nick.   2021 celebrating the 25th anniversary of "Königshafen" exhibition layout!
https://www.ngaugeforum.co.uk/SMFN/index.php?topic=50050.0

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