DCC Power Booster - Will this work???

Started by richd286, September 16, 2010, 10:34:27 PM

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richd286

Just read that an economical way to boost the power to your DCC system is to use something many people may already have...

The ac/dc converter from an old laptop.  I have 2!!  The web site said that the output of 18 volts and 4.5 amps was ideal to power an expanding DCC layout.   Does anyone have experience with this? The site is very reliable.   

richg

How about a link to this alleged economical way to boost power. We see this question every so often. This question scares me.
The controllers are designed for a certain power and voltage. If you are not a techie, don't mess with what works.
I have been working with electrical/electronics for over forty years and have seen too many issues with stuff like this that people "thought" they knew. Over the years I have found many tricks using this stuff but will usually never mention them to people who do not understand the basics. I do not want to be responsible.
If you really want to know, do it and give us a result of the "experiment".

Rich

richd286

#2

Everything I have read on this website supports many other websites I have researched.  Why would this not be true?

http://dccconcepts.com/index_files/DCCwiringpower.htm

Extract of website:

As a modeller I like to pass on good tips, and here is one that can save you some money on a mid powered DCC system power supply.

LAPTOP COMPUTERS regularly die, but the power supply that plugs into them is almost always still fit and healthy. Look for them at work, at friends, anywhere... they are usually free once the computer dies!

They DO vary. 15 to 18 volts, always DC, from 3 to 5 amps. MOST will be perfect, but look for 15 volts as the best choice for your DCC system. Just cut off the DC input plug at the end of the lead and hey presto –a high quality, really well regulated and presto power supply... NO CHARGE!


Jim Banner

While heaters and incandescent light bulbs do not care whether they are supplied with ac or dc, many electronic circuits do.  Some are happy only when fed ac.  Others prefer dc.  Many can operate off either ac or dc but the maximum and minimum voltage limits are different depending on the type of current.  Check the limits, either in the manual or like Hunt says, check with the manufacturer.  Once you know what the limits are, DO NOT EXCEED THEM.

Watch out for cheap transformers that have much higher output voltages when lightly loaded.  A transformer rated at 15 volts at its rated current output may sound just fine for powering up your command station.  But stop all the trains and the voltage may go up to 20 volts or more.  This may cause problems if the maximum rating for the command station is 18 volts.  Or it may not.  Your command station may be able to deal with the slight over voltage until the day that your power line surges momentarily to 150 volts and your command station is fed 25 volts or so.  If you notice lights dimming or brightening when motors kick in, this type of surging is a very real possibility.

Computer power supplies are normally regulated.  But grabbing a power supply off a failed computer may still lead to disaster, particularly if an internal fault in that power supply is what killed the computer.

Lastly, there is a question of current rating.  Some of the DCC introductory sets may rely on the power supply to limit the current fed to the command station.  But even with the more advanced sets, it is wise to use a fuse in series with the supply if the supply is rated at a higher current than the command station or booster.  This fuse should never blow in normal service but if the command station or booster ever faults, the fuse can keep a minor repair bill from suddenly becoming the cost of a full replacement..

Running more than one booster from a single power supply is possible if the power supply has a high enough current rating and the boosters are designed to allow this.  Most are not.  In that case, attempting to economize on power supplies can lead to blowing every decoder on the layout whether it is running or not.

Bottom line, if you are not thoroughly familiar with DCC wiring in general and with the technical specifications of your DCC system in particular, you should stick to the power supplies recommended by the manufacturer of your system.

Jim 
Growing older is mandatory but growing up is optional.

richg

Quote from: richd286 on September 16, 2010, 11:21:05 PM

Everything I have read on this website supports many other websites I have researched.  Why would this not be true?

http://dccconcepts.com/index_files/DCCwiringpower.htm

Extract of website:

As a modeller I like to pass on good tips, and here is one that can save you some money on a mid powered DCC system power supply.

LAPTOP COMPUTERS regularly die, but the power supply that plugs into them is almost always still fit and healthy. Look for them at work, at friends, anywhere... they are usually free once the computer dies!

They DO vary. 15 to 18 volts, always DC, from 3 to 5 amps. MOST will be perfect, but look for 15 volts as the best choice for your DCC system. Just cut off the DC input plug at the end of the lead and hey presto –a high quality, really well regulated and presto power supply... NO CHARGE!



Good link. Thanks.

It is alway nice to include a link to what you are discussing. That way everyone is hopefully on the same page.

That is fine but has nothing to do with increasing the capability of a DCC system. It is all about power distribution for a layout and a clean rugged power source.
Read the whole page again and do not make assumtions.

Rich

NarrowMinded

I live by the rule for every cheap trick there is an expensive repair.

NM

richd286

I haven't made any assumptions yet.  I asked if anyone has experience with this claim.  Like most others I put caution ahead of experimentation.  Yes it is a good link,  lots of good info about DCC.