Patent ID: 6307724
Filing Date: 2001-10-23
Classification: H02H

Abstract:
An accessory apparatus which is connected to a main apparatus and receives power from a power source of the main apparatus, comprising:a connector including a first terminal to be connected to a first power potential of the main apparatus, a second terminal to be connected to a second power potential of the main apparatus, and a third terminal to be connected to a ground potential of the main apparatus;a first circuit to be connected to said first, second and third terminals; anda first device for preventing said first circuit from being applied a voltage higher than a rated voltage of said first circuit in a direction from said third terminal to said first terminal in case that said second terminal is connected to the second power potential of the main apparatus with said first terminal being connected to the first power potential of the main apparatus, without said third terminal being connected to the ground potential of the main apparatus.