Hi all, I know this is probably really basic, but I've done research and have been flooded with information regarding the topic and now can't find what is best for my project.
In essence, I'm using a motorsport engine management system to trigger a MOSFET using pulse width modulation in order to modulate the speed of some cooling fans.
Ive got two circuits to make. One with one 7A 12V fan, and another with two 5A 12V fans. Wanting to use low side switching. How do I decide what MOSFET to use and which one is best suited for my use?
Thanks in advance

 

What is the source for the MOSFET PWM signal?
What is that signal voltage and frequency?

 

What is the source for the MOSFET PWM signal?
What is that signal voltage and frequency?

The source pin of the MOSFET will be grounded, but the gate will be controlled by an auxiliary output on the ems. The signal voltage and frequency is what I can't find in my specs. I may be able to modify this depending on what works best

 

You in an automobile environment ? One assumes 12V ...?

Regards, Dana.

 

The signal voltage and frequency is what I can't find in my specs. I may be able to modify this depending on what works best

Can you measure it?
Do you have an oscilloscope?

If not, we can assume it's 5V at some reasonably low frequency and go from there.

 

You in an automobile environment ? One assumes 12V ...?

Regards, Dana.

It's a management system which has the capability of outputting 5V and 8V

Can you measure it?
Do you have an oscilloscope?

If not, we can assume it's 5V at some reasonably low frequency and go from there.

I believe there are 5v outputs and 8v but I cannot find the frequency

 

Is the 5V/8V output the PWM signal?

Select a logic-level type N-MOSFET [Vgs(th)max ≤2V] with at least a 50V rating and an ON resistance of 10mΩ maximum.
Connect a 1N4004 diode across each set of fan motor terminals (cathode to plus voltage).