How to understand the field effect tube
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- Date : 2022-08-17
Is the rated current of the FET the current that causes the FET to fuse?
Not. It should only be seen as a specification of the nominal, and the current flowing through the field effect tube to what extent, when the fuse this in the field effect tube product standards have detailed provisions for it, but also due to the different standards and provisions vary. FET has a "fusing factor" whose value is greater than "1" (generally between 1.1 and 1.5), it is "conventional non-fusing current" and the "rated current" ratio. It can be seen that, even if the current flowing through the FET is greater than its rated current and does not exceed the conventional non-fusing current, the FET should not melt down phenomenon.
What is the slow-break FET?
Slow-break FETs are also called time-delay FETs, and their time-delay characteristics are demonstrated by the fact that they can remain intact when the circuit has a non-fault pulse current and can provide protection against long overloads. Some circuits in the switch instantaneous current is greater than several times the normal operating current, although the peak of this current is very high, but it appears for a very short time, we call it pulse current or inrush current. Ordinary field effect tube is not able to withstand this current, such a circuit if the use of ordinary field effect tube I'm afraid it can not be turned on properly, if you use a larger specification field effect tube, then when the circuit is overloaded and not protected. Delayed field effect tube melt by special processing, it has the role of energy absorption, adjust the amount of energy absorption can make it that can resist the inrush current and overload protection.
What is the meaning of the breaking capacity of the FET?
When the current between the conventional non-fusing current and the rated breaking capacity (of current) specified in the relevant standards acts on the FET, the FET should be able to operate satisfactorily and without endangering the surrounding environment. Field effect tube is placed in the circuit of the expected fault current must be less than the rated breaking capacity of the standard current, otherwise, when the fault occurs field effect tube fuse will continue to fly arc, ignition, field effect tube burn, together with the contact parts melt, field effect tube markings can not be identified and other phenomena. Of course, poor quality field effect tube breaking capacity does not meet the requirements of the standard, the use of the same will occur when the above-mentioned hazards.
What is the significance of studying the temperature rise of the FET?
The temperature rise of the FET is the specified current flowing through the FET, the temperature rise of the FET, that is, the measured temperature minus the value of the ambient temperature. Because the melt of the field effect tube is more sensitive to temperature, in a certain temperature for a long time, its melting point and impedance will change, this change will affect the accuracy of the field effect tube. This is commonly referred to as the field effect tube aging. Aging of the field effect tube used in the circuit is very dangerous, so we should pay attention to the temperature rise of the field effect tube in the production and use of field effect tube. Similarly, we should also note that even after a long period of use of the field effect tube did not fuse, it may have aged, it is best to replace.
What does the voltage drop of the FET indicate?
The voltage drop of the FET is the voltage drop across the FET under rated current conditions. It reflects the internal resistance of the field effect tube, its value should not be too large. If the internal resistance (voltage drop) is too large FET installed in the circuit, it will affect the system parameters of the circuit, making the circuit does not work properly. The standard voltage drop not only has its value of the upper limit of the provisions, but also its consistency has also made provisions.
How to understand the rated voltage of the field effect tube?
FET fuse or not depends on the size of the current flowing through it, and the circuit has nothing to do with the operating voltage. The rated voltage of the FET is proposed from the perspective of the safe use of the FET, which is the highest working voltage of the circuit in which the FET is placed in a safe working condition. This means that the field effect tube can only be placed in the circuit where the operating voltage is less than or equal to the rated voltage of the field effect tube. Only then the field effect tube can work safely and effectively, otherwise, when the field effect tube fuse will continue to fly arc and be voltage breakdown and hazardous circuit phenomena.
Not. It should only be seen as a specification of the nominal, and the current flowing through the field effect tube to what extent, when the fuse this in the field effect tube product standards have detailed provisions for it, but also due to the different standards and provisions vary. FET has a "fusing factor" whose value is greater than "1" (generally between 1.1 and 1.5), it is "conventional non-fusing current" and the "rated current" ratio. It can be seen that, even if the current flowing through the FET is greater than its rated current and does not exceed the conventional non-fusing current, the FET should not melt down phenomenon.
What is the slow-break FET?
Slow-break FETs are also called time-delay FETs, and their time-delay characteristics are demonstrated by the fact that they can remain intact when the circuit has a non-fault pulse current and can provide protection against long overloads. Some circuits in the switch instantaneous current is greater than several times the normal operating current, although the peak of this current is very high, but it appears for a very short time, we call it pulse current or inrush current. Ordinary field effect tube is not able to withstand this current, such a circuit if the use of ordinary field effect tube I'm afraid it can not be turned on properly, if you use a larger specification field effect tube, then when the circuit is overloaded and not protected. Delayed field effect tube melt by special processing, it has the role of energy absorption, adjust the amount of energy absorption can make it that can resist the inrush current and overload protection.
What is the meaning of the breaking capacity of the FET?
When the current between the conventional non-fusing current and the rated breaking capacity (of current) specified in the relevant standards acts on the FET, the FET should be able to operate satisfactorily and without endangering the surrounding environment. Field effect tube is placed in the circuit of the expected fault current must be less than the rated breaking capacity of the standard current, otherwise, when the fault occurs field effect tube fuse will continue to fly arc, ignition, field effect tube burn, together with the contact parts melt, field effect tube markings can not be identified and other phenomena. Of course, poor quality field effect tube breaking capacity does not meet the requirements of the standard, the use of the same will occur when the above-mentioned hazards.
What is the significance of studying the temperature rise of the FET?
The temperature rise of the FET is the specified current flowing through the FET, the temperature rise of the FET, that is, the measured temperature minus the value of the ambient temperature. Because the melt of the field effect tube is more sensitive to temperature, in a certain temperature for a long time, its melting point and impedance will change, this change will affect the accuracy of the field effect tube. This is commonly referred to as the field effect tube aging. Aging of the field effect tube used in the circuit is very dangerous, so we should pay attention to the temperature rise of the field effect tube in the production and use of field effect tube. Similarly, we should also note that even after a long period of use of the field effect tube did not fuse, it may have aged, it is best to replace.
What does the voltage drop of the FET indicate?
The voltage drop of the FET is the voltage drop across the FET under rated current conditions. It reflects the internal resistance of the field effect tube, its value should not be too large. If the internal resistance (voltage drop) is too large FET installed in the circuit, it will affect the system parameters of the circuit, making the circuit does not work properly. The standard voltage drop not only has its value of the upper limit of the provisions, but also its consistency has also made provisions.
How to understand the rated voltage of the field effect tube?
FET fuse or not depends on the size of the current flowing through it, and the circuit has nothing to do with the operating voltage. The rated voltage of the FET is proposed from the perspective of the safe use of the FET, which is the highest working voltage of the circuit in which the FET is placed in a safe working condition. This means that the field effect tube can only be placed in the circuit where the operating voltage is less than or equal to the rated voltage of the field effect tube. Only then the field effect tube can work safely and effectively, otherwise, when the field effect tube fuse will continue to fly arc and be voltage breakdown and hazardous circuit phenomena.
