Abstract: A master pressure control device of an electric booster sets an upper limit of current supplied to an electric motor in accordance with an operation amount of an input member to a current limit value A when a condition for limiting the driving of the electric motor is satisfied due to a decrease of voltage of a vehicle power source. The master pressure control device sets the upper limit of the current supplied to the electric motor in accordance with the operation amount of the input member to a current limit value B when the condition for limiting the driving of the electric motor is cancelled due to restoration of the voltage of the vehicle power source to normal while a brake pedal is operated. The current limit value B is larger than the current limit value A used when the driving of the electric motor is limited.

Abstract: A master pressure control device of an electric booster sets an upper limit of current supplied to an electric motor in accordance with an operation amount of an input member to a current limit value A when a condition for limiting the driving of the electric motor is satisfied due to a decrease of voltage of a vehicle power source. The master pressure control device sets the upper limit of the current supplied to the electric motor in accordance with the operation amount of the input member to a current limit value B when the condition for limiting the driving of the electric motor is cancelled due to restoration of the voltage of the vehicle power source to normal while a brake pedal is operated. The current limit value B is larger than the current limit value A used when the driving of the electric motor is limited.

Abstract: A braking system includes an electric motor configured to output a braking force, and a controller configured to control the electric motor. The controller is supplied with electric power from both a main power source and an auxiliary power source. The electric motor has a first state in which the electric motor is supplied with electric power from the main power source when the main power source has a voltage V1 equal to or higher than a threshold value Va; a second state in which the electric motor is supplied with electric power from the auxiliary power source, and the voltage V1 of the main power source is lower than the threshold value Va; and a third state in which the electric motor is supplied with electric power from the main power source, and the voltage V1 of the main power source is lower than the threshold value Va.

Abstract: A braking system includes an electric motor configured to output a braking force, and a controller configured to control the electric motor. The controller is supplied with electric power from both a main power source and an auxiliary power source. The electric motor has a first state in which the electric motor is supplied with electric power from the main power source when the main power source has a voltage V1 equal to or higher than a threshold value Va; a second state in which the electric motor is supplied with electric power from the auxiliary power source, and the voltage V1 of the main power source is lower than the threshold value Va; and a third state in which the electric motor is supplied with electric power from the main power source, and the voltage V1 of the main power source is lower than the threshold value Va.