The defrost timer is typically provided to remove frost on an evaporator in a refrigerator. The defrost timer includes a circuit board, a first terminal, a second terminal, a third terminal, a fourth terminal, a switching unit, a first AC line, a second AC line, a third AC line and a fourth AC line. The first AC line is provided on the circuit board and connects the first terminal and the switching unit. The second AC line is provided on the circuit board and connects the second terminal and the switching unit. The third AC line is provided on the circuit board and connects the third terminal and the switching unit. The fourth AC line is provided on the circuit board and connects the fourth terminal and the switching unit. Distance between the third AC line and the fourth AC line is at least 5 mm.