What load in car uses three Pulse to switch

You know you need to include more details than that. By "load" do you mean an electrical load, like a fan motor, light, or power window, a mechanical load such as the various clutch packs in a transmission, or a hauling load, meaning passengers and cargo?

What pulses are you referring to? Three presses of a push button switch? Three pulses for a digital computer signal?

What kind of problem are you trying to solve? We also use engine size, mileage, and transmission type to tailor our answers. Please include that information.