# #3) Booster --> Cooling Fan



## ED-RRR (Jun 4, 2015)

(#1) --> Required Cooling Fan Information..

Special Notes: 
The information shown applies to Digitrax [DCC]..
This procedure is "not" limited to "other" [DCC] systems..
If your [DCC] manufacture uses rear air cooling fins
this procedure will also help your [DCC] system.. 
If your power supply has cooling slots
this procedure will also help.. 

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Special Note:
The Digitrax DCS100 (Prod Date 01/27/1996) 
Still remains the "same" !!
(2015 - 1996) = 19 years old <-- LooK

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(private e-mail received) 
(Friend of Mark Gurries)

To Ed; (ED-RRR)
I am a electric engineer and many decades ago designed power supplies..
Some boosters such as Digitrax still have "inefficient" analog power regulators.. 
The heat of the analog power regulator can limit the steady state output 
to less than [HALF] the rated current and external fans are often required.. 
All my boosters are Digitrax so I am familiar with the problem..
From (Censored)..
He has a very large club HO model train layout 
using over (x10) Digitrax [DCC] units..

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#1) Cooling: (Digitrax)
Digitrax instructs to have good air flow..
Digitrax unit is sitting on a shelf with little air flow..

#2) Cooling: (Digitrax)
DB200+ (2008)
DB200+.pdf (file)
1.1.2 Heat Dissipation
If you experience frequent over temperature shut-downs,
add a small fan to help cool the booster.. 

#3) Cooling: (Digitrax)
http://www.digitrax.com/tsd/KB869/troubleshooting-
guide-for-digitrax-command-station/
3..If the Command Station or Booster unit shuts down frequently:
•Try direct cooling by using a small fan 
to blow air onto the heat sink..

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Warning:
--> Look at picture posted = Warning
- A closed rear backing on shelf..
- Behind the Digitrax unit/units must be 100% open..
- This also applies to "all" powered systems..
- To allow for free air flow..

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Special Notes:
I want to keep this project inside (x1) "thread" only to minimize confusion..
Since the project is quite large..
I have posted several "postings" by (#'s).. 

(#1) --> Required Cooling Fan Information..
(#2) --> Required Calculations..
(#3) --> Different Variable Pots..
(#4) --> Hardware Required..
(#5) --> Electronic Noise Reduction..
(#6) --> Fan Mounting ..

Please wait till "all" of my (x6) postings are down loaded,
before posting a reply in this "thread" (Thanks) :smilie_daumenpos: 
......


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## ED-RRR (Jun 4, 2015)

*(#2) --> Required Calculations..*

"Using" a variable pot for each individual cooling fan..

Special Notes..
Computer fans operate between ?.V-DC and 12.V-DC..
Most computer fans when operating at 12.V-DC
can be a little "noisy"..
That is why there are "Fan Speed Controllers"..
Most computer fan speed controllers
operate 5.V-DC --> 12.V-DC

Most 80mm x 80mm (12VDC) Cooling Fan [3 1/8" x 3 1/8"]
[Maximum Fan Input]
Volts: 12 ----> 12
Amps: .12 ----> 0.3 
Ohms: 100 ----> 40
Watts: 1.44 --> 3.6

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Problem:
There are many different types of computer fans
small up to very large..
Most 80mm x 80mm fans operate 
at 12.V-DC between .12Amps --> 0.3Amps 
Larger fans may/will require higher "Amperage"..

Special Note:
I tested a (80mm x 80mm) computer fan..
- 12.V-DC @ 0.12Amps fan motor..
- It would not function correctly "under" 8.V-DC

V = A × R
A = V / R 
R = V / A
W = V x A 

Calculations: (12V --> 5V)
V = 7.Volts (12.Volts - 5.Volts)
A = .12Amps
R = 58.3 Ohms (7.Volts / .12Amps) 
W = .84 Watts (7.Volts x .12Amps)

Calculations: (12V --> 5V)
V = 7.Volts (12.Volts - 5.Volts)
A = 0.3Amps
R = 23.3 Ohms (7.Volts / 0.3Amps) 
W = 2.1 Watts (7.Volts x 0.3Amps)

......


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## ED-RRR (Jun 4, 2015)

*(#3) --> Different Variable Pots (x5)..*

I highly recommend adding a "variable" pot..

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Option (#1):
--> Look at picture posted = (#1) Fan Speed Control
Can be quite expensive.. 
Zalman Fanmate2 is designed for a computer tower..
Over engineered for this usage..

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Option (#2):
--> Look at picture posted = (#2) Fan Speed Control
On Ebay $8.00 = ($2.00 per fan).. 
Will fit into 3.5" computer bay..
A computer can power the (x4) cooling fans..<-- LooK
LooK: 
- You may "not" like the lighted knobs..
- You might be able to disconnect the LED's..
- Has 0.7Amps for each channel
- For larger fans

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Option (#3):
--> Look at picture posted = (#3) Variable Pot
Add (x1) variable pot to each fan..
Do a price ($'s) comparison for each (x1) pot..
May not be easy to purchase required pot..

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Option (#4):
--> Look at picture posted = (#4) Variable Pot
Add (x1) variable "trim" pot to each fan..
These are very "small" in size (Thumb Size)..
Also very cheap on Ebay (x10 $1.50)..
Search 3296W-500
Easier to purchase required pot..
Require 50 Ohm variable resistor..
https://www.bourns.com/pdfs/3296.pdf
P/N 3296W-500 (50 Ohm)

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Option (#5):
--> Look at picture posted = (#5a) Variable Pot
--> Look at picture posted = (#5b) Variable Pot
- These Are Small (PC) Trim Pots..
- Usually only .25 Watt
- Can "not" be used for this application..

......


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## ED-RRR (Jun 4, 2015)

*(#4) --> Hardware Required..*

For each (x1) individual unit..

- Require (x1) 80mm x 80mm (12VDC) Cooling Fan [3 1/8" x 3 1/8"]
- Require (x4) rubber "O" rings (vibration insulation)
- Require (x2) round head #8 sheet metal screws (mounting)
- Require (x1) 12.V-DC power supply
- Require (x1) wire (red + black) #22 or #24 AWG
- Require (x2) small wire nuts

- Require (x1) small 0.1uF capacitor ("Optional")

- Require (x1) computer fan speed control ("Optional")
-OR-
- Require (X1) variable pot ("Optional")
-OR-
- Require (X1) bourns variable pot ("Optional")
- 50 Ohm variable resistor..
https://www.bourns.com/pdfs/3296.pdf
P/N 3296W-500 (50 Ohm)


Special Notes:
The (x2) small wire nuts are to allow for easy fan removable
to clean a dirty fan..
There are also many "different" wire connectors for fans..

Caution:
This fan size fits perfectly behind Digitrax unit..
You can use a larger fan
but the bourns variable pot is based on 0.3Amp motor.. 

......


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## Cycleops (Dec 6, 2014)

You may be a electronics engineer but the vast majority on here are not, so please try to say what you are trying to say in easy to understand language, otherwise it will be of no use to the members here.


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## ED-RRR (Jun 4, 2015)

*(#5) --> Electronic Noise Reduction..*

Procedure: "Optional"

--> Look at picture posted = Capacitor 
--> Look at picture posted = Capacitor Added

CTI Electronics: (Noise Reduction) 
http://www.cti-electronics.com/
Documents --> Electronic Noise Reduction Techniques..
The cooling fan electric motor with arcing motor brushes
is right next to a [DCC] command unit..

Going by CTI Electronics: (Commutator Noise Suppression Capacitor) 
I myself added a "small" 0.1uF capacitor
across the fan motor wires..

Pull out the (x2) wires from the fan casing
and add a "small" 0.1uF capacitor across the (x2) motor wires..
The closer the capacitor is to the motor terminals
the better it will function..

......


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## ED-RRR (Jun 4, 2015)

*(#6) --> Fan Mounting..*

Procedures: "Fan Direction"..
--> Look at picture posted = (#1) Fan Direction
Cut off the fan wire connector..
Connect a 9.V-DC battery or 12.V-DC power supply to fan..
Note the fan blowing direction <-->..
Be 100% sure knowing the fan blowing "direction"..

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Procedures: "Fan Mounting"..
LooK --> Positions of Boosters Locations..
--> Look at picture posted = (#2) Fan Position
--> Look at picture posted = (#3) Fan Position

Do --> (#2) Fan Position -OR- (#3) Fan Position
Mount cooling fan in required location
for "maximum" air flow..
- Be sure to add (x2) rubber "O" rings..
- This will prevent fan sound vibrations..
- Use (x2) mounting screws..

=============================================

Procedures: "Fan and Pot Wiring"..
LooK --> (x3) Different Wiring Options..

Option (#1):
--> Look at picture posted = (#4a) Variable Pots
Cut off the fan wire connectors..
Mount inside a computer or sitting on a shelf..
Add (x1) variable pot to each fan..

Option (#2):
--> Look at picture posted = (#5a) Variable Pot
--> Look at picture posted = (#5b) Variable Pot
Hot glue gun pot into place..
Add (x1) variable pot to each fan..

Option (#3):
--> Look at picture posted = (#6a) Variable Pot
--> Look at picture posted = (#6b) Variable Pot
Hot glue gun Trim pot into place..
Add (x1) variable pot to each fan..

......


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## ED-RRR (Jun 4, 2015)

*Digitrax units get hot..*

Cycleops thanks for "NOT" respecting my wishes !!

Please wait till "all" of my (x6) postings are down loaded,
before posting a reply in this "thread" (Thanks) 



Cycleops said:


> You may be a electronics engineer but the vast majority on here are not, so please try to say what you are trying to say in easy to understand language, otherwise it will be of no use to the members here.


Question:
Would you or any other individual in this forum believe me
if I only said a cooling fan is required ??
Digitrax units get hot..
I would be attacked for posting unproven information..

I am not an electrical engineer..
That is why I have the backing of an electrical engineer..

LooK: There are also Digitrax instructions !! 
......


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## wvgca (Jan 21, 2013)

hmmm .. I can see if the airflow is severely blocked, a supply or controller may overheat, but in general usage most are not operated at full capacity, and heat is not normally an issue unless the unit consistently goes into thermal shutdown .. and a fan of the larger size that you indicated is normally used on computer switching power supplies of 300 watt and larger .. the smaller 5cm muffin fans would have adequate flow for most applications, have an arrow on them for air flow direction, are usually 'brushless' , and can easily be driven from a 5 to 9 volt wall wart, depending on design ..if some sort of regulation is required, a thermistor style temperature actuated relay can be purchased for three bucks on fleabay including shipping, and will turn the fans on only when needed, and trip adjustable ... probably just be easier to open up the enclosure or move them to a less restricted area ... my humble opinion ..


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## Cycleops (Dec 6, 2014)

ED-RRR said:


> I am not an electrical engineer..
> That is why I have the backing of an electrical engineer..
> ......


This is the internet, remember? You could have said you are an electrical engineer and no one would have been any the wiser. I'm a nephew of the King of Sweden. Geddit?

Sorry I 'dissed' you. May I be turned into a pillar of salt, or a length of EZ track. Your choice.

As for the fan issue it seems like a lot of hot air to me.


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## Fire21 (Mar 9, 2014)

Wouldn't it have been easier to just say, "If your power supply and/or boosters get hot, install a fan for cooling"? Just wondering......


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## ED-RRR (Jun 4, 2015)

*Spinning Wheels --> Going No Where..*



Cycleops said:


> This is the internet, remember? You could have said you are an electrical engineer and no one would have been any the wiser. I'm a nephew of the King of Sweden. Geddit?
> Sorry I 'dissed' you. May I be turned into a pillar of salt, or a length of EZ track. Your choice.
> As for the fan issue it seems like a lot of hot air to me.


This "MAY" be an example of an individual going no where..
......


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## ED-RRR (Jun 4, 2015)

*Unproven Information..*



Fire21 said:


> Wouldn't it have been easier to just say, "If your power supply and/or boosters get hot, install a fan for cooling"? Just wondering......


As I stated in this --> "Thread"

Question:
Would you or any other individual in this forum believe me
if I only said a cooling fan is required ??
Digitrax units get hot..
I would be attacked for posting unproven information..:smilie_auslachen:
......


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## ED-RRR (Jun 4, 2015)

*Discussions..*



wvgca said:


> my humble opinion ..


That is what forums are for..
To exchange different views and ideas..
You also brought up some excellent opinions..:smilie_daumenpos:



wvgca said:


> hmmm .. I can see if the airflow is severely blocked, a supply or controller may overheat, but in general usage most are not operated at full capacity, and heat is not normally an issue unless the unit consistently goes into thermal shutdo<script id="gpt-impl-0.7591509819237189" src="http://partner.googleadservices.com/gpt/pubads_impl_75.js"></script>wn ..


You are 100% correct..
But what I am concerned about is Digitrax units running "hot" and "not" shutting down..
Some boosters such as Digitrax still have "inefficient" analog power regulators.. 
The [HEAT] of the analog power regulator can limit the steady state output 
to less than [HALF] the rated current and external fans are often required.. 
Why not keep a the [HEAT] down by at all times by using a "cooling fan" all the time.. 
This will improve Digitrax units performance..:thumbsup:



wvgca said:


> .. and a fan of the larger size that you indicated is normally used on computer switching power supplies of 300 watt and larger ..


All fans will make an unwanted "noise" at 12.V-DC..
Reducing the voltage to the fan will reduce the unwanted "noise"..
But this will also "reduce" air flow by almost 50%..:thumbsdown:



wvgca said:


> .. the smaller 5cm muffin fans would have adequate flow for most applications,..


I had these small fans on my AC/DC adjustable voltage converters..
At full speed 12.V-DC they made a small winy noise..
Reducing the V-DC power supply will result in very little air flow.. :thumbsdown:



wvgca said:


> .. have an arrow on them for air flow direction, are usually 'brushless' ,..


Thanks for pointing this out because I totally forgot this..
Yes there is an air flow arrow on one of the sides..:smilie_daumenpos:
I would still want to insure that the fan direction is 100% correct.. 



wvgca said:


> .. can easily be driven from a 5 to 9 volt wall wart, depending on design....


At first I was actually thinking the exact same idea..:thumbsup:
But "every" fan will operate at a different "Minimum" Voltage..
But "every" fan will operate at a different "Required" Amperage..
There are too many "variables" involved..
That is why I have suggested using a "variable pot"..



wvgca said:


> .. usually 'brushless' ...


Yes many cooling fans are "'brushless"..
But do you know 100% that your cooling fan is "'brushless" ??

......


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