Regenerative Braking System

[musa1236]

Hello . I would like to slow down the car with an alternator (instead of pads). However, unlike a normal regenerative braking system, I want this braking power to be controllable. I wanted to ask if there was a CVT (Continuously Variable Transmission) gear available. On a bike we're driving, we can easily turn the pedals while in 1st gear, but we're forced in 7th gear. If I reverse the same logic and assume that the alternator is the brake in a car, can I determine the gear radius by decelerating the CVT gearbox to the brake pedal? Another example as applied to the engine brake is to reduce the speed of the vehicle at a certain speed and slow down the car if I increase the speed.