Good day! I'm coming slowly back to electronics after 35 years, and am rusty.
At the moment the project at hand is limiting the speed and power draw of a pair of brushless DC fans, ca. 2.25A ea. with a stated range of 6-14V. First attempt was a 12V PWM fan controller, which works, but results in a lot of noise, and according to Comair-Rotron, a shortened FET life. They suggested varying a smooth DC voltage instead.
I am looking at adjustable DC buck-boost converter modules to provide the fans with linear-appearing voltage, and see that a large percentage of those on the market have both voltage and current control. I know how to figure out the usual power law math, but I am not sure what behavior to expect out of one of these controllers.
Additionally, I would simply use a buck converter, but the commonly available modules have too much voltage overhead, and with the AGM battery source I didn't want to have a range of only 6-9V available.
My speculation is that if I leave the "current limit" trim pot set wide open, the fan motors will draw the current they need, up to about 4.5A at full draw. Would this be correct?
I am intending to remove the voltage trim pot and replace it with a remotely mounted single-turn pot for fan speed control.
Is there a reason to pay any attention to current limiting? To be relatively safe, how much overhead should I leave; e.g., if I know the fans are rated at 4.5A, would the 5A converter be safe?
Hope the question is appropriate, and thanks!
At the moment the project at hand is limiting the speed and power draw of a pair of brushless DC fans, ca. 2.25A ea. with a stated range of 6-14V. First attempt was a 12V PWM fan controller, which works, but results in a lot of noise, and according to Comair-Rotron, a shortened FET life. They suggested varying a smooth DC voltage instead.
I am looking at adjustable DC buck-boost converter modules to provide the fans with linear-appearing voltage, and see that a large percentage of those on the market have both voltage and current control. I know how to figure out the usual power law math, but I am not sure what behavior to expect out of one of these controllers.
Additionally, I would simply use a buck converter, but the commonly available modules have too much voltage overhead, and with the AGM battery source I didn't want to have a range of only 6-9V available.
My speculation is that if I leave the "current limit" trim pot set wide open, the fan motors will draw the current they need, up to about 4.5A at full draw. Would this be correct?
I am intending to remove the voltage trim pot and replace it with a remotely mounted single-turn pot for fan speed control.
Is there a reason to pay any attention to current limiting? To be relatively safe, how much overhead should I leave; e.g., if I know the fans are rated at 4.5A, would the 5A converter be safe?
Hope the question is appropriate, and thanks!