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Saturday, September 15, 2018

Speed Control For Endless Breeze Fan



The Endless Breeze portable 12 volt fan is made by Fan-Tastic Vent.  I use it in my Four Wheel Camper (FWC) to move air around the camper.  It also works good outside the camper on a 12 volt extension cord.  I have Fan-Tastic vents in the ceiling of my camper that I have a also modified with the PWM motor speed control.  Here is that modification post.  http://macaloney.blogspot.com/2018/?m=1

As with the Fantastic fan/vent in the ceiling of my FWC, the motor runs at a high speed for me on the low setting.  The Endless Breeze comes with a speed switch that gives 3 speed settings and my modification does not change the 3 speed settings if the PWM is fully on.  As with the roof units the fans can be noisy even on the low setting, thus adding the PWM speed control a nice change for noise when sleeping.

My problem:

When I just want the fan to provide a light breeze In my FWC camper, I want to be able to set the fan speed to what I want for air movement.  I also would like to conserve my solar power LiFePo4 battery system with lower my current draw when running the fan all night.

The answer:

Below is the PWM speed controller that I bought from Amazon.  What Pulse-Width Modulation does in this case is sends 12 v on and off.  The faster the 12 volt pulse the faster the motor spins.  When the pulse is off there is no power draw.  Therefore a 50/50 cycle the motor uses half the current.



Here is what WIKI has on PWM
https://en.m.wikipedia.org/wiki/Pulse-width_modulation

I tested the current draw of the fan to ensure that the 2 amp PWM will work with it.  I did this by putting the PWM between the fan’s 12 plug and the battery.




Above is the open fan with the 3-position speed switch with a plastic cable tie holding wires from the PWM I added.  

With the PWM fully on the 3-position switch still functions as it was designed.



On the other side of the fan top from the 3-position switch I have installed the PWM



Above you can see the open space opposite the 3-position switch where the PWM fit nicely.



More of my wiring.  The added wiring is run along the fan edge like the wiring that comes with the fan.



Here is how the fan looks now with the PWM added to the top.



My test showed that the PWM would adjust the speed of the fan from full speed to off.  I set the speed to be a constant light breeze and  I was only drawing .49 amps.

Note the PWM has a light on the circuit board that shines through the white plastic so you can see that it is turned on.

Brent

macaloney@hotmail.com










2 comments:

  1. Interesting. Did you do any testing of amps at a given fan speed using the PWM versus the switch? In other words, determine the reduction in amps from using the PWM compared to the same fan speed using the switch?

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  2. Happy Runner, That’s a good question as it helps explain how the PWM works.

    The fan can work the same with before and after adding the PWM. So, when the 3 position fan speed switch is on high the rpm would be the same with PWM fully turned on as the voltage to the fan is the same and the PWM is not pulsing to reduce duration.

    Therefore, the PWM slows the fan as you turn down the PWM because it is now only sending power intermittently to the fan rather than continuously without the PWM.

    I don’t have a method of measuring rpm as I do this, but it didn’t matter to me as it is completely variable/linear. The wider the 12 v pulse the slower the fan and the less power is consumed.

    In my small FWC camper high speed is very high and around 2 amps. My testing found that a nice light breeze uses about .5 amps. A stronger “I’m hot need to cool down” with fam directly pointed at me was about 1 amp. I just don’t see the need to use the standard switch settings as I just life to set the speed for the need.

    The same logic went into adding the PWM to the Fantastic roof vent fan. I get to regulate the speed I like and I get noise and amp usage reduction.

    I’m sure there are plenty of people out there that are happy with the factory settings, but I wasn’t.

    Bob Wells of CRVL recently published a YouTube video where he reviews portable fans. The Endless Breeze was one of them. One of his comments was that it was noisy, but moves a lot of air. He expressed my opinion and the reason for the mod to add the PWM. It’s a coincidence that we published so close to each other. My mod was done earlier this summer and I just got to publish.

    Brent

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