System, device and method for detecting connection of connecting structure

An apparatus for detecting a connection to detect whether there is a connection with a first device having a first connection terminal including a 1-1 contact point and a 1-2 contact point and a first reactance element connected to the first connection terminal, the apparatus comprising:

• a second connection terminal having a 2-1 contact point and a 2-2 contact point corresponding to the 1-1 contact point and the 1-2 contact point;
• a first resistance element;
• a first frequency generator connected to a first end of the first resistance element and configured to apply a signal having a frequency varying in a predetermined range to the first device through the second connection terminal via the first end of the first resistance element, wherein a second end of the first resistance element is connected to the second connection terminal;
• a first comparator having a first input terminal connected to the first end of the first resistance element and a second input terminal connected to the second end of the first resistance element and configured to compare signals at the first end and the second end of the first resistance element, and
• a first controller configured to determine whether the first connection terminal of the first device is connected to the second connection terminal by using an output signal of the first comparator.

A method of detecting a connection by which a second device detects whether there is a connection with a first device, the first device including a first connection terminal having a 1-1 contact point and a 1-2 contact point and a first reactance element connected to the first connection terminal, the method comprising:

• a signal application operation in which the second device generates, using a first frequency generator connected to a first end of a first resistance element, a signal having a frequency varying in a predetermined range and applies the signal to the first device through a second connection terminal having a 2-1 contact point and a 2-2 contact point corresponding to the 1-1 contact point and the 1-2 contact point via the first end of the first resistance element, a second end of the first resistance element being connected to the 2-1 contact point or the 2-2 contact point;
• a signal comparison operation in which the second device compares signals at the first end and the second end of the first resistance element;
• and
• a connection determination operation in which the second device determines whether the first connection terminal of the first device is connected to the second connection terminal by using a result of the comparison between the signals at the first end and the second end of the first resistance element.