Protection circuit and charging equipment

A protection circuit configured to connect:

• a contact positive electrode terminal, a first contact negative electrode terminal, and a second contact negative electrode terminal that are exposed to an outside in a connector portion connected to a device including a secondary battery;
• and
• a positive electrode terminal and a ground terminal provided in a power output unit configured to output power supplied to the secondary battery via the contact positive electrode terminal, the first contact negative electrode terminal, and the second contact negative electrode terminal, wherein
• the protection circuit includes:
• a P-type metal-oxide-semiconductor field-effect transistor (MOSFET) connected between the contact positive electrode terminal and the positive electrode terminal;
• a first electrical path configured to connect the contact positive electrode terminal and a drain terminal of the P-type MOSFET;
• a second electrical path configured to connect the positive electrode terminal and a source terminal of the P-type MOSFET;
• a first N-type MOSFET connected between the second contact negative electrode terminal and the ground terminal;
• a third electrical path configured to connect the second contact negative electrode terminal and a drain terminal of the first N-type MOSFET, the third electrical path being grounded;
• a fourth electrical path configured to connect the ground terminal and a source terminal of the first N-type MOSFET;
• a fifth electrical path configured to connect the first contact negative electrode terminal and the fourth electrical path or the second electrical path via a resistor;
• a sixth electrical path configured to connect a gate terminal of the P-type MOSFET and the fifth electrical path between the first contact negative electrode terminal and the resistor;
• and
• a seventh electrical path configured to connect a gate terminal of the first N-type MOSFET and the fifth electrical path between the sixth electrical path and the resistor.