i) The rated current and voltage, fusing temperature (TF), service temperature (th) and maximum temperature (TM) of each temperature fuse shall be used under the specified parameters.
II) when selecting the installation position of the fuse, pay attention not to transfer the stress to the fuse due to the vibration in the finished product and the displacement of other accessories.
III) it shall be installed where the temperature will not rise above the maximum service temperature after the Miniature Thermal Cutoff Devices is blown.
IV) cannot be used in machines with liquids or humidity maintained above 95%.
v) The temperature fuse shall be installed in a place that can only sense the heat source of the temperature fuse. When the structure is unavoidable, thermal resistance spacers shall be set. For example, when installing on the heater, pay attention not to connect directly, so as to prevent the hot wire from heating to the temperature fuse
VI) if the temperature fuse is connected in parallel or continuously passes through overcurrent and overvoltage in order to increase the current of the temperature fuse, the internal contact of the temperature fuse will be damaged and its normal operation will be affected. Therefore, it cannot be used under the above conditions.
Although the temperature fuse has high reliability in design, the abnormal conditions that a single temperature fuse can cope with are limited after all. In addition, due to man-made or unforeseen force majeure, if the temperature fuse is damaged and cannot function normally, the circuit cannot be cut off in time when the machine is abnormal. Therefore, more than two temperature fuses with different fusing temperatures shall be used when the machine is overheated, when the wrong action has a direct impact on the human body, when there is no circuit cutting equipment except fuses, and when high safety is required.
The thin temperature fuse is specially developed for over temperature protection of lithium-ion battery. Its working principle is the same as that of the second temperature fuse mentioned above. The circuit is connected with low melting point alloy. The low melting point alloy is wrapped with melting aid resin. The low melting point alloy is connected with metal guide plate and sealed by plastic material. When the internal temperature of the battery rises to a certain level due to short circuit inside or outside the battery or other reasons, the temperature fuse close to the battery cell will quickly blow, so as to cut off the external circuit of the battery and prevent the battery from exploding and personal injury. As handheld electronic devices need to be more and more portable, the size of temperature fuse needs to be as small as possible and as thin as possible. At present, the thinnest temperature fuse can be 0.65mm thick and 2.7mm wide. The internal resistance of temperature fuse is also very small, only about 8m Ω. The power consumption in standby mode is very small, which can greatly increase the standby time of lithium-ion battery.
