The most common power transfer devices for doors are what?

The most common power transfer devices for doors are what?

• A. Electric hinges / flexible power transfer cords
• B. Smart cards / biometric readers
• C. Pneumatic closers / hinges
• D. Battery backup / solar panels

Answer: (A)

In door systems that need electrical power to run components on the door (like locks, sensors, or operators), the power must pass through the moving door while it swings. The most common solution is an electric hinge with a flexible power transfer cord or a through-door pass-through. This setup provides a continuous electrical path as the door moves, is reliable, and is widely used, making it the standard choice. Smart cards and biometric readers are credentialing technologies, not methods for delivering power through a moving door. Pneumatic closers or hinges handle the mechanical action of closing the door rather than transferring electrical power. Battery backup or solar panels supply power to the system but do not function as the devices that transfer power through the door itself.

In door systems that need electrical power to run components on the door (like locks, sensors, or operators), the power must pass through the moving door while it swings. The most common solution is an electric hinge with a flexible power transfer cord or a through-door pass-through. This setup provides a continuous electrical path as the door moves, is reliable, and is widely used, making it the standard choice.

Smart cards and biometric readers are credentialing technologies, not methods for delivering power through a moving door. Pneumatic closers or hinges handle the mechanical action of closing the door rather than transferring electrical power. Battery backup or solar panels supply power to the system but do not function as the devices that transfer power through the door itself.