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Controlling a fan with PWM and a counter using NI 9482

Hi all,


I am very new to labview and am currently attempting to control a fan using the Ni cDAQ-9178 chassis and a NI 9482 Module (electromechanical relay).


I am connecting the fan up to a separate power source and then have the one PWM connection connected to CH0a. When I run the program the module makes a clicking noise that changes frequency when I change the duty cycle which makes me believe the program is working, but I can not get the fan to turn on change speeds. (I know the fan works because I can bypass the PWM to get it to run at full power).


The fan should be running at 100 HZ and at a 15-90% duty cycle. One thing I also read is that there is an internal pull up resistor and that I should have an open collector output (I am not 100% sure what this means). 


I feel like I am missing something simple here as to why I can not get this to work. Any help would be greatly appreciated.






PWM photo.png


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You have incorrect hardware.  A SPST relay is just not a counter output.

"Should be" isn't "Is" -Jay
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