Skip to main content

Slightly AC confused, having been 2 rail DC for years but no onboard electronics.

 

OK, graduating from old 3-rail with universal motors running on AC: all 'modern' 3 rail equipment has DC can motors, and DC electronics with AC to the track and then rectified on board, right?

 

Where is the line between AC and DC with TMCC and Legacy? The plethora of systems is something that I don't plan to actively pursue, I just want to understand the basics if I end up with equipment that has a problem.

 

Any good links for someone who just showed up in 3 rail? All the electronics questions I see on the forum make me want to skip the bells and whistles and bypass right to the motor.

 

Original Post

Replies sorted oldest to newest

The AC input is rectified immediately going to the board by bridge rectifiers.  Regulated 5 volt DC or whatever goes to the chips on the PC board. Motor voltage is provided by a larger bridge rectifier on more conventional boards. Not sure how it is done with legacy. Polarity is reversed to change direction. Without any board a bridge rectifier to the motor will run it in one direction. 

 

A DC offset on the AC blows the whistle in conventional operation.

 

Dale H

Last edited by Dale H
Originally Posted by Firewood:

Slightly AC confused, having been 2 rail DC for years but no onboard electronics.

 

OK, graduating from old 3-rail with universal motors running on AC: all 'modern' 3 rail equipment has DC can motors, and DC electronics with AC to the track and then rectified on board, right?

 

Where is the line between AC and DC with TMCC and Legacy? The plethora of systems is something that I don't plan to actively pursue, I just want to understand the basics if I end up with equipment that has a problem.

 

Any good links for someone who just showed up in 3 rail? All the electronics questions I see on the forum make me want to skip the bells and whistles and bypass right to the motor.

 

For early Lionel TMCC and Legacy board they take AC in and half rectify to make DC to run a 5VDC regulator and power the microchips.  The AC passed through for motor and accessory control since early TMCC was the universal motor.

 

When can motors requiring DC were used the AC for the motor was rectified with a FWBR and used for the motor.

 

Later legacy and MTH system are DC based.  They take the AC in and immediately rectify it to DC to drive both microcontrollers off a regulator and power motor and accessories.


You really need to look at the board to see which method is used, but that is the basics.  G

Last edited by GGG

Add Reply

Post

OGR Publishing, Inc., 1310 Eastside Centre Ct, Ste 6, Mountain Home, AR 72653
800-980-OGRR (6477)
www.ogaugerr.com

×
×
×
×
Link copied to your clipboard.
×
×