Railway Controller Question.

crosstownk

Years ago I was a big model railway enthusiast and now that my little guy got a train set from Santa it seems to have got me going again.

I was always under the impression that the old Hornby stuff (1970s & 80s) was 12VDC - maybe I'm wrong. I notice that my son's new train set is powered by a Hornby controller that outputs 19VDC. (I measured it at 18V) It's a crappy controller and looks and feels pretty cheap and tacky.

However, I have an old Hammant & Morgan power supply (one twin supply and a third slave) that outputs 1A at 12VDC on each output. I measured the output to be 14VDC.





So my questions are:

1. How will this affect the running of more modern locos if they are intended for 19VDC when my vintage controllers can only supply 12? Slower is the first thing that comes to mind.

2. How will the 19VDC affect my older trains that are designed to work at 12VDC? Will the excess voltage do any damage?

coolwings

Track rails are made of steel, therefore they are a compromise for wear vs conducting electric DC. If carrying the current to your loco was the main issue the track would be made of copper.
Electrical resistance of the steel rails causes voltage brownout.
The extra voltage of power supply units is so the power can be pushed into the track and overcome the resistance. That's why many supply units are 16V, not 12V. I never saw an 19V supply before.
The lower the voltage, the more connection points you must place along a long track.

crosstownk

coolwings wrote: »

Track rails are made of steel, therefore they are a compromise for wear vs conducting electric DC. If carrying the current to your loco was the main issue the track would be made of copper.
Electrical resistance of the steel rails causes voltage brownout.
The extra voltage of power supply units is so the power can be pushed into the track and overcome the resistance. That's why many supply units are 16V, not 12V. I never saw an 19V supply before.
The lower the voltage, the more connection points you must place along a long track.

My bad.

After reading your post I checked the manual for the Hornby controller. It illustrates 19VDC from the wallwort power adapter IN to the controller but 12VDC from the controller to the track.

crosstownk

Out of sheer boredom I've just replaced the crappy Hornby controller with my old H&M. WOW - train speed has increased by almost 50%. Obviously the H&M delivers more current.