How Does PWM actually control the fuel pump motor?

[C6Z06]

Thanks to people like CarlC I have learned alot about high performance fuel pump systems but I still thirst for more understanding.

I understand that high performance fuel systems need to be sized to provide lots of fuel under maximum load conditions but it is adviseable to use systems like the one vaporworx provides to minimize fuel overheating, vapor lock and wasted energy.

I understand systems like theirs and soem of the OEMs' use Pulse Width Modulation to control the pump based on actual need at any given time.

What I don't understand yet is how does pwm actually manifest itself at the pump motor?

Does it cause it rotate continuously at variable speeds or is it actually causing it to start and stop at a high frequency that just looks continuous?



Is it basically turning the pump into a stepper motor or is it providing a signal that is then used to vary the voltage to the pump?

Please forgive me if this is a subject that has already been covered. I haven't found it yet.

[dhutton]

pwm control cycles the power to the pump on and off. The duty cycle is the ratio of on time to off time. 100% PWM is the pump powered on continuously, 50% is it on and off for equal amounts etc. The pump coasts through the off times, it doesn't actually stop rotating because the frequency of the cycling is too high. At low duty cycles the pump may stall or never start rotating.

At least this is my understanding, hope this helps.

[SLO_Z28]

pwm control cycles the power to the pump on and off. The duty cycle is the ratio of on time to off time. 100% PWM is the pump powered on continuously, 50% is it on and off for equal amounts etc. The pump coasts through the off times, it doesn't actually stop rotating because the frequency of the cycling is too high. At low duty cycles the pump may stall or never start rotating.

At least this is my understanding, hope this helps.

^Dead on.