# Digitrax Power Supply --> PS514 (Costly)



## ED-RRR (Jun 4, 2015)

I am presently totally rebuilding my layout power control panel
to improve the performance of all Digital Command Control (DCC) Circuit Boards..
For my Digitrax DCS100 5 Amp (DCC)
I used a Spring Haven 18.V-AC @ 5.Amp power supply..
I'm now in the process to use "regulated" V-DC to power my DCS100 unit
to improve (DCC) performance..

Digitrax DCS100 5 Amp (DCC)
- Minimum input 15 volts DC @ 5.Amp
- Nominal Input 21 volts DC @ 5.Amp
- Maximum input 28 volts DC @ 5.Amp

Digitrax power supply "PS514" 
- 70 Watt
- (x7) V-DC output selections
- High efficiency power supply
- Not "regulated" power supply
- Price: US $59.00 MSRP 

Watts Volts Amps
70 12 5.8
70 13.8 5.1
70 15 4.7
70 16.8 4.2
70 19 3.7
70 20 3.5 <-------
70 24 2.9

PS514 selector switch set at 20.V-DC = "Only" a 3.5 Amp "output" !!
With this type of performance at US $59.00 MSRP, I find it quite costly !!

I am presently looking at building my own 20.V-DC @ 5.Amp "regulated" power supply
using a 12.VDC @ 5.Amp power supply and a 10.Amp boost converter
for around US $20.00 

Once I have completed this project, I will post it..
......


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## fcwilt (Sep 27, 2013)

Good luck.

One thing though:

20 VDC at 5 Amps is 100 Watts.

If the boost converter was 100% efficient then you would need your 12 VDC input power supply to also be 100 Watts - which works out to appx 8.4 Amps.

So you need to determine the actual efficiency of the converter and from that you can determine the required current ratting of your input power supply.


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## johnfl68 (Feb 1, 2015)

The issue with price is because the 18V that DigiTrax normally uses is a non-standard voltage and not common in electronics use.

If you go to a standard voltage that is commonly used, like 24 VDC, the price for AC/DC Switching Power Supplies comes way down.

For example, a Delta 24 VDC 6.5A power supply is about $30 plus shipping:
http://www.mouser.com/ProductDetail...Sgtpzc5jgEB8BFaY7h6a6HEU5YAzFOCkJvCKRx%2bBQ==

The DCS100 is supposed to handle up to 28 VDC, so 24 VDC should not be an issue.

And nothing to build.

John


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## higgsbosonman (Nov 17, 2014)

I had to google our system, and you almost gave me a heart attack! We just picked up a DCS200 and the matching booster for our club, and they can operate at input voltages down to 12V DC. I wonder why they can't get the 5A system to run at 12V when the 8A system does?

If you want a good basic 12v power supply that can handle anything you can throw at it, our club aquired two HP proliant 575w power supplies to run our system. Each one can dish out around 50A at 12V, so if you re using a booster to raise the voltage up, the extra oomph of these PSUs would be very helpful. They're designed to run at full output for years, since they are supposed to run server computers, and are extremely tough. If you ever plan on expanding your system, these could probably run 3 to 4 of your boxes even when boosting the power up to 24V at around 20A. They're all over ebay for about $15 a piece, but you usually have to get them in pairs.

Word of warning, though; you need to solder jumpers to them to make them think they are connected to a computer, or they won't turn on.


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## higgsbosonman (Nov 17, 2014)

Forgot to mention that you can also hook the power supplies I mentioned up in series with one having a floating ground and get 24V at 50A, but that could be a bit dangerous if you don't know what you're doing.


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## fcwilt (Sep 27, 2013)

higgsbosonman said:


> I had to google our system, and you almost gave me a heart attack! We just picked up a DCS200 and the matching booster for our club, and they can operate at input voltages down to 12V DC. I wonder why they can't get the 5A system to run at 12V when the 8A system does?


While you can run a DCS-xxx at 12 VDC you are limiting the voltage on the rails to less than the Digitrax suggested value.

YMMV.


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## higgsbosonman (Nov 17, 2014)

Okay, so I'll only be getting 10 or so volts when I hook up our system to only one?

Kind of glad we bought two of those PSUs...


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## fcwilt (Sep 27, 2013)

higgsbosonman said:


> Okay, so I'll only be getting 10 or so volts when I hook up our system to only one?
> 
> Kind of glad we bought two of those PSUs...


That sounds about right - easy enough to measure if you have a 'scope or a RRampMeter.


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## ED-RRR (Jun 4, 2015)

*Thanks (New Calculations)*



fcwilt said:


> Good luck.
> One thing though:
> 20 VDC at 5 Amps is 100 Watts.
> If the boost converter was 100% efficient then you would need your 12 VDC input power supply to also be 100 Watts - which works out to appx 8.4 Amps.
> So you need to determine the actual efficiency of the converter and from that you can determine the required current ratting of your input power supply.


"fcwilt" Thanks for your reply (greatly appreciated)..:smilie_daumenpos:
Reminding me of "Ohms Law"..
I had to look at your calculations..
Your calculations are based on a power supply of
--> 20.VDC @ 5.0Amps (constant current)..

As per Digtrax web site (present) the DCS100 5 Amp (DCC)
- "Was" Minimum input 12 volts V-DC
- Recommended power supply = Digitrax PS514 or equivalent
- Minimum input 15 volts V-DC

Then I had to re-check my calculations..
To re-confirm that this project will work..
I used reverse calculations based on how Digitrax units actually operate..
The Digitrax power supply PS514 set at 15.VDC sends out 4.7Amps 
The Digitrax power supply PS514 set at 20.VDC only sends out 3.5Amps..

My (Updated) VDC power output "project": (Regulated)
--> 15.VDC @ 4.7Amps (constant current)..
- "No" DCS100 -OR- DB150 will require "over" 4.7Amps..
- Power supply (Input) = 12.VDC @ 5.0Amps (60 Watts).. (high efficiency)
- Boost Converter = Voltage/Load Regulation: ± 0.5% (@ 10.Amp)..
- Power Supply (Output) = 15.VDC @ 4.7Amps (70 Watts)..(regulated)
......


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## ED-RRR (Jun 4, 2015)

*Cautions (x2)*



johnfl68 said:


> The issue with price is because the 18V that DigiTrax normally uses is a non-standard voltage and not common in electronics use.
> If you go to a standard voltage that is commonly used, like 24 VDC, the price for AC/DC Switching Power Supplies comes way down.
> For example, a Delta 24 VDC 6.5A power supply is about $30 plus shipping:
> http://www.mouser.com/ProductDetail...Sgtpzc5jgEB8BFaY7h6a6HEU5YAzFOCkJvCKRx%2bBQ==
> ...



#1)
Caution: (Very Important)
--> This power supply is at 6.5Amps..
Digitrax Units rated @5.Amps can "not" be powered "over" 5.Amps..
That is why Digitrax PS2012 20 Amp power supply comes with
•One "Y" cable (P/N YC52) Included for convenience with dual 5 amp protected outputs..

#2) 
Caution: (Very Important)
--> This power supply is a "Switching Power Supply"..
Do "NOT" use any type of "Switching" power supplies 
on a [DCC] direct command control train layout.. 
The main disadvantage of a "Switching" power supply
compared to a "Linear" power supply is --> "Noise"..

"Noise" = Electronic Wave Interference.. 
Totally effects how well any "Direct Command Control" 
(DCC) unit will function correctly.. 
The "Switching Power Supply" voltage oscillations 
and the constant connecting and disconnecting 
from the source creates "Too" much "Noise"..
--> This will interfere With "all" [DCC] units
on how well the unit/units will correctly operate.. 
The "Linear Power Supply" also creates some amount of "Noise"
but nowhere near as much as the "Switching Power Supply"..

.......


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## fcwilt (Sep 27, 2013)

ED-RRR said:


> My (Updated) VDC power output "project": (Regulated)
> --> 15.VDC @ 4.7Amps (constant current)..
> - "No" DCS100 -OR- DB150 will require "over" 4.7Amps..
> - Power supply (Input) = 12.VDC @ 5.0Amps (60 Watts).. (high efficiency)
> ...


You are doing it again - you cannot get out more power (70 Watts) then you put in (60 Watts).


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## johnfl68 (Feb 1, 2015)

ED-RRR said:


> #1)
> Caution: (Very Important)
> --> This power supply is at 6.5Amps..
> Digitrax Units rated @5.Amps can "not" be powered "over" 5.Amps..
> ...




The Power Supply I listed was just an example.
It will only supply 6.5A if the DCS100 or other command station/booster draws that much. If Digitrax properly designed, it should not draw more than 5A if fully loaded down. If the DCS100 is only drawing 1.5A, the Power Supply is only going to give it 1.5A, not 6.5A.

The PSYC52's are a great idea when using a 20A power supply as there is a lot of potential in the case of a short or failure. All they contain are two 5A thermally self resetting fuses (Poly Fuses). They are also a good idea to use with other supplies closer to 5A, as well as any other form of current protection, PM42 Quad Power Manager, fuses, etc. That goes with common sense.

The PS514 is more than likely a Switching Power supply, a good majority of the power supplies out there are now switching power supplies. 
The PS2012 is also more than likely a Switching Power supply. 

Linear Power Supplies, are big and bulky with large transformers that waste power and create heat, that is why the are no longer used that much these days.



> http://www.digitrax.com/tsd/KB326/dcs100-and-db150-power-supply/
> 
> Any power supply that meets the following requirements can be used to power the DCS100 and DB150s.



Digitrax says "Any power supply...", there is nothing on their site that I could find about using linear, or about not using switching.

I could not find any reputable DCC site that says anything about needing to use Linear Power Supplies instead of Switching.

Again, with the majority of power supplies that everyone is using being switching, I doubt that any of the DCC manufacturers would have not already taken this into consideration. So there should not be any issues with using switching power supplies.

John


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## ED-RRR (Jun 4, 2015)

*Caution (x1)*



higgsbosonman said:


> Forgot to mention that you can also hook the power supplies I mentioned up in series with one having a floating ground and get 24V at 50A, but that could be a bit dangerous if you don't know what you're doing.


#1)
Caution: (Very Important)
--> Using higher then rated Amperage for Digitrax units..
Go to:
http://www.digitrax.com/products/power-supplies/
PS2012 20 Amp Power Supply 12 to 23 VDC
Read: Instruction Sheet.pdf
Digitrax highly recommends to protect their units by using 5.Amp -or- 8.Amp "fuses"..
......


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## fcwilt (Sep 27, 2013)

A quality switching power supply will not be a problem.

Over current protection is a good idea and can be easily be added between any power supply and the command station.


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## ED-RRR (Jun 4, 2015)

*Power Supply*



johnfl68 said:


> The Power Supply I listed was just an example.
> It will only supply 6.5A if the DCS100 or other command station/booster draws that much. If Digitrax properly designed, it should not draw more than 5A if fully loaded down. If the DCS100 is only drawing 1.5A, the Power Supply is only going to give it 1.5A, not 6.5A.
> John


#1)
Caution: (Very Important)
--> Using higher then rated Amperage for Digitrax units..
Go to:
http://www.digitrax.com/products/power-supplies/
PS2012 20 Amp Power Supply 12 to 23 VDC
Read: Instruction Sheet.pdf
Digitrax highly recommends to protect their units by using 5.Amp -or- 8.Amp "fuses"..
......


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## mopac (Feb 24, 2011)

Over current protection is a good idea and can be easily be added between any power supply and the command station.

Last year I purchased a digitrax 8amp command station, an 8amp booster and the 
ps2012 power supply to power both units. I wonder why digitrax doesn't include an
8 amp y-cable with power supply only a 5amp cable. I know I can make up an 8amp
fused cable. My layout is yet unbuilt. I bought the 8amp system because each unit
was only 20 to 25 dollars more than the 5amp units. Cheapest 3 amps you will ever
purchase. I will also use 2 PM42s. 5amp might be enough. I want to be able to run
up to 12 power locomotives around half with sound. I also bought the 8 amps so the
command station and booster will not have to run at max capacity. I have heard the
units will get pretty warm running at max capacity. They do have large heat fins on the back. I just don't think electronics and heat go together. Is my thinking correct?


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## higgsbosonman (Nov 17, 2014)

Fusing makes sense, and I will definitely be using them because people do stupid things with the layout. As for supplying too much current, I know for a fact that unless one catastrophically fails and shorts out, it will not accept more than 8 amps. The only way more amps would flow is if you ramped the voltage up and blew some insulation off. As for switching vs linear power supplies, the switching power supplies in servers MUST deliver an exceptionally clean source of power or it will cause premature failure of the motherboard and other expensive bits, so they are very clean (my room mate hooked his up to an O-scope and the AC ripple was minuscule, and it surprised him how nice they are). If you need to clean up a switching power supply, though, the best bet you'd have is to put capacitors in parallel with the output of the system rated for the proper voltage. However, I know this won't be necessary with our system. I might try it if I can get them, though.


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## ED-RRR (Jun 4, 2015)

*Digitrax Power Supplies*



johnfl68 said:


> The PS514 is more than likely a Switching Power supply, a good majority of the power supplies out there are now switching power supplies.
> The PS2012 is also more than likely a Switching Power supply.
> John



PS514 70W AC Power Supply
http://www.digitrax.com/products/power-supplies/ps514/
- comes with DC adaptors
- 7 selectable output voltages, 12V, 13.8V, 15V, 16.8V, 19V, 20V, 24V --> DC output
Read This:
Note: For DCS100/DB150 Minimum input should be: 12 volts AC or 15 volts DC.

PS2012 20 Amp Power Supply 12 to 23 VDC
http://www.digitrax.com/products/power-supplies/ps2012/
This big regulated power supply delivers more power with less heat
for more efficient booster operation. 
- Says regulated power supply (not switching regulated power supply) (Digitrax is not lying)..
- It also has an "Amp" meter (not a "volt" meter)..
- Also note the words (more power with less heat).
- Also note the words (more efficient booster operation). 
--> Switching Regulated Power Supply = "Controls" Voltage Output..
--> Regulated Power Supply = "Controls" Amperage Output..
......


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## ED-RRR (Jun 4, 2015)

*Electronic "Noise"*



johnfl68 said:


> Digitrax says "Any power supply...", there is nothing on their site that I could find about using linear, or about not using switching.
> I could not find any reputable DCC site that says anything about needing to use Linear Power Supplies instead of Switching.
> Again, with the majority of power supplies that everyone is using being switching, I doubt that any of the DCC manufacturers would have not already taken this into consideration. So there should not be any issues with using switching power supplies.
> John


Electronic "Noise"
I purchased (x12) control models [DCC] from this company.. 
CTI Electronics
http://www.cti-electronics.com/
They state the importance how electronic "noise" will effect critical electronic circuit boards..
This will be an eye opener for many..
Read this "application note".. 
Noise Reduction Techniques - This Applications Note describes methods for reducing electrical noise 
on a model railroad to ensure reliable operation of your CTI computer control system.
......


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## ED-RRR (Jun 4, 2015)

*DCS100 Power Supply (2015)*



johnfl68 said:


> The DCS100 Power Supply Image
> John


DCS100
The voltage supply you have shown was last updated on April 11, 2012, 3:29 p.m. 
This is now what is required..
http://www.digitrax.com/products/command-stations-boosters/dcs100/
Note: Accepts either 50/60 Hz AC or DC input from power supply (sold separately) 
Recommended power supply: Digitrax PS514 or equivalent 
Maximum input 22 volts AC or 28 volts DC 
Minimum input 12 volts AC or 15 volts DC

PS514 70W AC Power Supply
http://www.digitrax.com/products/power-supplies/ps514/
For DCS100/DB150 Minimum input should be: 12 volts AC or 15 volts DC.
....


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## ED-RRR (Jun 4, 2015)

*Electronics and Heat*



mopac said:


> I have heard the units will get pretty warm running at max capacity. They do have large heat fins on the back. I just don't think electronics and heat go together. Is my thinking correct?


You hit the nail right on the head..
That is why we are instructed to allow good air flow for the Digitrax units..
A cooler Digitrax unit will function better..
I went (x1) step farther..
Digitrax unit is sitting on a shelf with little air flow, 
so add (x2) small spacers and hot glue gun a small cooling fan on "Top" of the back fins.. 
Dirt cheap on Ebay (US$4.00)..
50mm x 50mm DC 12V Cooling Fan [2." x 2."]..
......


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## johnfl68 (Feb 1, 2015)

Confirmed from email from Digitrax support a few minutes ago about using switching power supplies, and their supplies being switching power supplies:



> You can use a switching power supply.
> 
> You are correct.


Email them directly, they will tell you the same thing, that there is nothing wrong with using a switching power supply. 


You are confusing "Regulated" with "Linear" it seams. Almost all Switching Power Supplies are Regulated.

Also the CTI Noise Reduction article says nothing about not using switching power supplies, it only says to use a good regulated power supply.

And yes the 20A supply is going to put off heat, if it were a linear supply, it would put off even more heat then that supply does. Any power supply that can provide that amount of current will put off heat when under load.


The whole point was you were complaining about the cost of Digitrax's power supplies, so you were going to try and kludge something together to save money. Nothing wrong with Digitrax products, they are good products.

I was trying to save you some hassle by showing you that there are other good power supplies that will work great that are less money.

John


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## fcwilt (Sep 27, 2013)

ED-RRR said:


> --> Switching Regulated Power Supply = "Controls" Voltage Output..
> --> Regulated Power Supply = "Controls" Amperage Output..
> ......


That is incorrect.

A regulated power supply, be it linear or switching, can be designed to provide constant voltage, constant current or switch from one mode to the other.

A constant voltage power supply, that does not have the ability to switch to a constant current mode, will typically still have current limiting to prevent damage in the case of a malfunction or short.

Of course simply limiting the current of a, say, a 50 Amp supply to it's max of 50 Amps still could do a lot of damage.

Which is why a common current limiting scheme used is called "foldback". In this case when an over current situation is detected the power supply drastically reduces the output voltage attempting to limit the current to much less then the max rated.


Someone suggested that additional filter caps could be added to the output of a switching power supply. This would only be needed for a poorly designed power supply. Switching power supplies, by their very nature, include filtering on the output to provide smooth DC power.


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## ED-RRR (Jun 4, 2015)

*My Final Reply --> This Thread..*

I have noticed that individuals are still reading this thread..
In part you are reading some "Incorrect" information..

I partially built my (DCC) model train layout
from (2001) --> (2006)..
DCC locomotives operating with DCC sound..
Now being retired I am now completely rewiring
my railroad layout using full (DCC) system..
Converting from V-AC --> V-DC operations..

I only stated that the Digitrax power supply PS514 (Junk)..

Instead of having a friendly group discussion (what forums usually do)
I get challenged by individuals saying my information is (B.S.)..
The other individuals: 
- Stated [Outdated] "Digitrax" manuals information..
- Stated [False] "Digitrax" manuals information..
- Stated [Dangerous] "Power" supply practices for (DCC)..

You know who you are..
I will be looking forward to seeing you in my "new threads".. 
--> What "expertise" advice you will have for "me"..
--> what electrical engineering advice you have.. 
--> Challenge actual Digitrax manuals..
--> Challenge a NMRA (DCC) electrical engineer..

My "Final" Reply --> This Thread..
I will "No" longer communicate in this forum..

:smilie_daumenneg:
- CAUTION - DANGER - WARNING - 

In "some" places this thread went totally out of control with:
- "Outdated" [DCC] information
- "False"[DCC] information
- "Dangerous" [DCC] information

- CAUTION - DANGER - WARNING - 

:smilie_daumenneg:
......


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## fcwilt (Sep 27, 2013)

Hi Hobo,

You seem to be upset and that is too bad - this is supposed to be a friendly place.

Reading back all of the posts it seemed to be a pretty good thread.

So stick around.


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## wvgca (Jan 21, 2013)

just read this through a couple of times start to finish ... quite enjoyable actually ... and definitely not boring ... as long as the locos go round and round in the end, its all good ..


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