NOVELTY - The circuit (100) has a thermal fuse (110) electrically connected in a main current path (30) and electric current flowing in the current path. A switching element (120) i.e. FET, is connected to the fuse to open and interrupt the electric current flowing in the current path. A controller is electrically connected to the switching element and the current path to turn on the switching element when overcurrent flows in the current path. A noise removing unit (140) electrically connects the controller to the switching element.    USE - Safety circuit for a battery pack (claimed) for performing charging and discharging of a battery i.e. secondary batteries e.g. nickel-hydrogen battery and lithium ion battery such as liquid electrolyte battery, solid polymer electrolyte battery and gel phase electrolyte battery, in a portable electronic device i.e. portable computer.    ADVANTAGE - The noise preventing diode electrically connects the switching element to the microcontroller to allow forward current to flow from the microcontroller to the switching element, so that the noise preventing diode removes noise by preventing current from flowing to the switching element until output voltage of the microcontroller exceeds threshold voltage of the noise preventing diode, thus eliminating need for complicated circuit to remove the noise by a Schottky diode passing a low frequency band signal to remove the noise in an effective manner. The circuit prevents overheating and explosion of an electronic device by interrupting the main current path of the electronic device. The circuit prevents the switching element from erroneously turning on and causing the thermal fuse to erroneously open and interrupt the main current path due to noise generated in the circuit for operating the switching element and noise generated by the printed circuit pattern acting as an antenna and receiving radio frequency (RF) signal transmitted by the radio set operating near the safety circuit.    DETAILED DESCRIPTION - The noise removing unit comprises a noise preventing diode i.e. Schottky diode. An INDEPENDENT CLAIM is also included for a battery pack comprising a battery.    DESCRIPTION OF DRAWING(S) - The drawing shows a circuit diagram of a safety circuit.    Sensing resistor (20)    Main current path (30)    Safety circuit (100)    Thermal fuse (110)    Fuse (111)    Heater (112)    Noise preventing diode (113)    Resistor (114)    Switching element (120)    Microcontroller (130)    Noise removing unit (140)