Abstract: A protection circuit is provided, which protects a battery pack from overcurrents and overvoltages using sensing means and a protection device having a heating resistor and a fuse element provided on a circuit board. This protection circuit allows for sharing a protection device regardless of the current rating and the voltage rating of the battery pack, thereby being manufactured at low costs.

Abstract: A protective element has a heat-generating member and a low-melting metal member on a substrate, in which the low-melting metal member is blown out by the heat generated by the heat-generating member, wherein at least two strips of low-melting metal member are provided as the low-melting metal member, for example, between the pair of electrodes that pass current to the low-melting metal member, so that the lateral cross section of at least part of the low-melting metal member is substantially divided into at least two independent cross sections. This protective element has a shorter and more consistent operating time. It is preferable here to provide at least two strips of low-melting metal member between the pair of electrodes that pass current to the low-melting metal member. It is also preferable to provide one strip of low-melting metal member having a slit in its center, between the pair of electrodes that pass current to the low-melting metal member.

Abstract: A secondary battery device 1 including multiple protective circuits U1-U3 connected in parallel and each having two fuses fa, fb connected in series, wherein a terminal tc of each heater h is connected to a switch element 4 via rectifier element D1-D3. Even if a potential difference is generated between terminals tc, no residual current flows because any one of the rectifier elements D1-D3 is reverse-biased.

Abstract: A protection circuit is provided. The protection circuit protects a battery pack from overcurrents and overvoltages using sensing means and a protection device having a heating resistor and a fuse element provided on a circuit board. This protection circuit allows for sharing a protection device regardless of the current rating and the voltage rating of the battery pack, thereby being manufactured at low costs. A protection circuit protects a battery pack having serially connected rechargeable batteries from overcurrents and overvoltages. The protection circuit includes a protection device having heating resistors and fuse elements provided on a circuit board, and sensing means for detecting an overvoltage across any of the batteries in the battery pack and switching a current flowing into the heating resistor. The protection circuit allows the sensing means in an overvoltage condition to switch on the current flowing through the heating resistor.

Abstract: A secondary battery with high safety is provided. A heater and a diode are connected in series, and a thermistor is connected in parallel with thus formed series circuit. A fuse is connected in series with thus formed parallel circuit to form a protective circuit, which is attached to an accumulator to complete a secondary battery. In the case of overcharging, the accumulator generates heat so that the thermistor heats up to increase the resistance value. As a result, the current pass through the heater, which generates heat to break the fuse. In the case of short circuit, the diode is reverse-biased and no current passes through the heater so that the fuse does not break.

Abstract: A secondary battery of the present invention a heat-sensitive element which varies in resistance value due to change of temperature is not placed on a path through which a charge or discharge current flows into or out of a storage battery. Accordingly, when a main switch element generates heat due to an overcurrent, a change in resistance value of the heat-sensitive element resulting from the heat will allow an auxiliary switch to be turned ON, thereby causing first and second auxiliary fuses to be blown. The charge or discharge current causes no power consumption at the heat-sensitive element, thereby providing high efficiency. The heat-sensitive element can be reduced in current capacity for use and it is suitable for compact design.

Abstract: A secondary battery of the present invention a heat-sensitive element which varies in resistance value due to change of temperature is not placed on a path through which a charge or discharge current flows into or out of a storage battery. Accordingly, when a main switch element generates heat due to an overcurrent, a change in resistance value of the heat-sensitive element resulting from the heat will allow an auxiliary switch to be turned ON, thereby causing first and second auxiliary fuses to be blown. The charge or discharge current causes no power consumption at the heat-sensitive element, thereby providing high efficiency. The heat-sensitive element can be reduced in current capacity for use and it is suitable for compact design.

Abstract: A secondary battery device 1 including multiple protective circuits U1-U3 connected in parallel and each having two fuses fa, fb connected in series, wherein a terminal tc of each heater h is connected to a switch element 4 via rectifier element D1-D3. Even if a potential difference is generated between terminals tc, no residual current flows because any one of the rectifier elements D1-D3 is reverse-biased.

Abstract: A protective circuit for a secondary battery is formed with a heater and a thermistor that are connected in parallel, and a main fuse is connected in series with the parallel circuit. In a secondary battery equipped with this protective circuit, a charging/discharging current passes through the protective circuit and is limited by the operation of the thermistor when the voltage applied during abnormal conditions is relatively low. On the other hand, the current will cause the main fuse to blow when the voltage during abnormal conditions is high.

Abstract: A heater 13 and a thermistor 14 are connected in parallel, and a main fuse 11 is connected in series with thus formed parallel circuit to form a protective circuit 6. In a secondary battery 5 of the present invention, a charging/discharging current passes through the protective circuit 6, so that current is limited by the operation of the thermistor 14 when the voltage applied during abnormal conditions is relatively low while the main fuse 11 blows when the voltage during abnormal conditions is high.

Abstract: A protective element contains a heat-generating member and a low melting metal member on a substrate, in which the low melting metal member is molten by the heat generated by the heat-generating member and flows onto electrodes, which causes the low melting metal member to blow out, Formula (1) below is satisfied: (cross-sectional area of the low melting metal member)/(surface area of the blowout-effective electrode)≦0.15  (1) Alternatively, Formula (2) below is satisfied: 2.5≦(inter-electrode distance)/(cross-sectional area of the low melting metal member)≦30  (2) wheren the inter-electrode distance is defined as the distance between two electrodes, among the low melting metal member electrodes onto which the molten low melting metal member flows, which are adjacent to each other with the low melting metal member interposed therebetween.

Abstract: A secondary battery with high safety is provided. A heater and a diode are connected in series, and a thermistor is connected in parallel with thus formed series circuit. A fuse is connected in series with thus formed parallel circuit to form a protective circuit, which is attached to an accumulator to complete a secondary battery. In the case of overcharging, the accumulator generates heat so that the thermistor heats up to increase the resistance value. As a result, the current pass through the heater, which generates heat to break the fuse. In the case of short circuit, the diode is reverse-biased and no current passes through the heater so that the fuse does not break.

Abstract: A protective element contains a heat-generating member and a low melting metal member on a substrate. The low melting metal member is caused to blow out by the heat generated by the heat-generating member. The number of locations on the low melting metal member which are able to blow out is larger than the number of locations which are supposed to blow out so that the protective element is endowed with a “fail-safe” function.

Abstract: A protective device comprises a fuse element provided to electrodes on a substrate. The fuse element has a liquidus point higher than the mounting temperature of the protective device, and has a solidus point lower than the mounting temperature of the protective device. The difference between the liquidus and solidus points is 5° C. or higher.

Abstract: An electrical current protection device capable of highly safe and rapid shutoff or suppression of electric current is disclosed. In addition to internal electrical current protection capabilities, external environmental triggers are also provided. The current protection device may include substrate-based thermal metallic fuse, PTC current-suppressing protection, thermal heat elements, integrated-circuit based voltage-drop detector, an FET-based current switch, and an external detector for environmental sensing and trigger.

Abstract: A protective element contains a heat-generating member and a low melting metal member on a substrate, in which the low melting metal member is molten by the heat generated by the heat-generating member and flows onto electrodes, which causes the low melting metal member to blow out, Formula (1) below is satisfied:

Abstract: A protective element contains a heat-generating member and a low melting metal member on a substrate. The low melting metal member is caused to blow out by the heat generated by the heat-generating member. The number of locations on the low melting metal member which are able to blow out is larger than the number of locations which are supposed to blow out so that the protective element is endowed with a “fail-safe” function.