How to control a fan with LabView

[Bhag]

Hi,

I'm new to LabView and am half-way through the manual. I'm trying to control a fan's speed (off, low, medium, high) with LabView and have a knob control in the front panel for that. I have connected the computer running LabView to the fan by means of a USB cable, USB hub, I/O unit, DC-DC converter, voltage controller (12V) and then the fan. But the fan cannot be switched on by Labview although I can spin the blades manually and measure that it reaches 12 V by a multimeter. What am I doing wrong? I already checked the USB hub and the computer's USB ports and they are all working fine.

[johnsold]

It is impossible to tell from your description.

Do you have a wiring error? Does the voltage controller produce enough current to run the fan?  Is the fan rated for 12 V? 

Does the fan run if you connect it directly to a 12 V power source, such as a car battery?

Please post your LabVIEW (LV) program and a complete diagram of your electrical connections (.png, .pdf, or .jpg).  Also tell us the models of the devices you are using and the OS and LV versions.

Lynn

[Bhag]

Hi Lynn,

Thanks for getting back to me so soon! I am a student and this is a project I inherited from 2 previous batches of students. I'll look to gain acces to their folders to see if I can find the block diagram and the vi (I only have the exe). If not, I'll draw the connections and provide all the other info.

[Bhag]

Hi,

Here is the vi, the visio diagram and the lauout picture that I found. I'm only trying to control the fan because it looks like 2 bulbs are missing from the solar panels, so they may not work because of the open circuit. But everything in the fan appears connected. I tested the USB signal from the PC and the LED's to indicate the loads from the vi (e.g. heater, lights, etc.) all light up on the actual hardware. However, the fan does not turn on! The fan/wind ebnergy system is the same setup as the solar/PV system. I appreciate any help you can provide.

[johnsold]

Which part of that controls the fan?

Have you tried a simplified version which only has the fan control code?

Lynn