As the elevator begins to accelerate through the partially set brake the controller sends full _______ to the brake coil to pick it fully.

As the elevator begins to accelerate through the partially set brake the controller sends full _______ to the brake coil to pick it fully.

• A. current
• B. resistance
• C. voltage
• D. power

Answer: (A)

The key idea is that the braking force from the brake coil is controlled by the magnetic field, which is determined by the current flowing through the coil. When the elevator starts to accelerate and the brake is only partially released, the controller delivers full current to the brake coil to generate enough magnetic force to pull the brake in for a full release. The coil’s resistance is a fixed property, so the current (not the voltage alone) sets the electromagnetic pull. Power is a function of current and voltage, but what the control system directly regulates to ensure proper brake release is the current.

The key idea is that the braking force from the brake coil is controlled by the magnetic field, which is determined by the current flowing through the coil. When the elevator starts to accelerate and the brake is only partially released, the controller delivers full current to the brake coil to generate enough magnetic force to pull the brake in for a full release. The coil’s resistance is a fixed property, so the current (not the voltage alone) sets the electromagnetic pull. Power is a function of current and voltage, but what the control system directly regulates to ensure proper brake release is the current.