Smoothed DC Power supply for DCC

[mervyn]

Does anyone use a smoothed power supply for their dcc layouts ? just a bit wary of using the standard plug in transformer that comes with the set .

[WIMorrison]

Can you explain more please?

 

What is the set you are talking about (and if it was supplied with a power supply then that should work with it), and by 'smoothed power supply' do you mean a SMPS?

[mervyn]

Morning ,just a bit cautious about using the supplied power supply that I have read can cause voltage spikes , and with dcc sound equipped locos being expensive  to replace the decoder, so am asking if anyone uses an alternative that is a bit more robust then a small plug based transformer, apologies if I didn't explain myself more clearly.

[newbryford]

1 hour ago, mervyn said:

Does anyone use a smoothed power supply for their dcc layouts ? just a bit wary of using the standard plug in transformer that comes with the set .

 

Yes.

I swapped my Lenz TR150 feeding a Lenz LZV100 for a 18vDC 5A regulated unit.

 

Suddenly the mysterious runaways stopped happening!

 

There will be those that say the main bridge rectifier inside the unit will only be working "one way" as it's passing DC and not rectifying DC, but I've had no problems in over 5 years.

 

As a previous poster says - what system have you got - some are supplied with a regulated unit anyway.

Edited November 4, 2022 by newbryford

[Crosland]

If the DCC system is supplied with, and designed to use, a transformer based supply then it will be fine. That in itself will not cause voltage spikes, who told you that? Was it someone trying to sell you their expensive brand of power supply?

 

Such a system will contain all the smoothing and regulation it requires.

 

The cheap EZ-Command actually requires a transformer (AC) supply.

 

Transformers have an inherent advantage in that they don't shut down near-instantaneously (generally within 10 ms or so) like a switch mode PSU (SMPS). Using a SMPS requires a very fast overload cutout in the command station/booster (which has implications for downstream cutouts) or active current limiting (which requires very careful thermal design and management).

 

 

[jamesed]

"Spikes" across your dcc system are far more likely to be caused by poor or inadequate dcc wiring. Frog juicers can also be a cause and should be avoided if possible. Frequent running through points against how they are set and causing a short will also cause spikes.  There are lots of threads on here discussing all these issues which are worth reading through if you are new to dcc.  If you are using the power supply that was supplied by the manufacturer of your dcc system then that's the best thing to use and shouldn't cause any problems (using anything else may invalidate the warranty).   Despite some of the horror stories you may read, dcc decoders are pretty robust, at least the decent quality ones are, and they will cope quite well with short circuits and transient voltage spikes.  Blowing up a decoder is very much an exceptional event not a common one.  If you are planning on investing in dcc sound locos and decoders then invest a bit of time first in making sure your dcc wiring is up to scratch. 

[mervyn]

Thanks for all the replies!