Direct current connector, alternating current/direct current input device, and alternating current/direct current input system

A system, comprising:

• a direct current connector, comprising:
• a ground contact;
• a positive electrode contact;
• a negative electrode contact;
• and
• a fixed contact;
• wherein the fixed contact protrudes outside of the direct current connector and is configured to prevent the direct current connector from being inserted into an alternating current appliance input socket having an external shape configured to prevent insertion of the fixed contact;
• and
• a general-purpose appliance input socket having an external shape configured to accommodate the fixed contact;
• wherein the fixed contact is configured to be inserted into the general-purpose appliance input socket having the external shape configured to accommodate the fixed contact;
• wherein the external shape of the general-purpose appliance input socket is configured to be able to receive both an alternating current connector and the direct current connector, and wherein the general-purpose appliance input socket comprises:
• a ground contact,
• a positive electrode contact, and
• a negative electrode contact;
• wherein the ground contact, the positive electrode contact, and the negative electrode contact of the general-purpose appliance input socket respectively connect to the ground contact, the positive electrode contact, and the negative electrode contact of the direct current connector when receiving the direct current connector;
• and
• wherein the ground contact, the positive electrode contact, and the negative electrode contact of the general-purpose appliance input socket respectively connect to a ground contact, a positive electrode contact, and a negative electrode contact of the alternating current connector when receiving the alternating current connector.

A general-purpose appliance input socket, comprising:

• a ground contact;
• a positive electrode contact;
• and
• a negative electrode contact;
• wherein the general-purpose appliance input socket has an external shape configured to accommodate a fixed contact of a direct current connector, wherein the fixed contact is configured to be inserted into the general-purpose appliance input socket having the external shape configured to accommodate the fixed contact and to prevent the direct current connector from being inserted into an alternating current appliance input socket having an external shape configured to prevent insertion of the fixed contact;
• wherein the external shape of the general-purpose appliance input socket is configured to be able to receive both an alternating current connector and the direct current connector;
• wherein the ground contact, the positive electrode contact, and the negative electrode contact of the general-purpose appliance input socket respectively connect to a ground contact, a positive electrode contact, and a negative electrode contact of the direct current connector when receiving the direct current connector;
• and
• wherein the ground contact, the positive electrode contact, and the negative electrode contact of the general-purpose appliance input socket respectively connect to a ground contact, a positive electrode contact, and a negative electrode contact of the alternating current connector when receiving the alternating current connector.