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2024/03/07

KTY81-120,KTY81-121,KTY81-122 Thermistors-Huagu Electronics

The KTY81-120 is a high-precision PTC linear thermistor with a maximum temperature of 175 degrees. The parameters are shown in the table below. Huagu Electronics is a professional thermistor manufacturer. The company mainly focuses on the research and development of thermistors, varistors and self-healing fuses. production. Companies rely on strong research and development capabilities to launch the latest PTC linear thermistor

2024/03/07

The main matters in the welding process of NTC temperature sensor-the difference between Teflon wire and PVC wire

Teflon is called Polytetrafluoroetylene in English, referred to as Teflon, PTFE, F4, etc. Teflon high-performance special coating is a fluorine coating with PTFE as matrix resin. The English name is Teflon, which is usually called Teflon because of pronunciation.

2024/03/07

KTY81-110,KTY82-110 Thermistor, KTY81-110 Temperature Sensor, KTY83/110-Huanju Electronics

The KTY81-110 is a high-precision PTC linear thermistor with a maximum temperature of 175 degrees. The parameters are shown in the table below. Huagu Electronics is a professional thermistor manufacturer. The company mainly focuses on the research and development of thermistors, varistors and self-healing fuses. production. Companies rely on strong research and development capabilities to launch the latest PTC linear thermistor

2024/03/07

Three elements of power type NTC thermistor selection

The size of the filter capacitor determines the size of the NTC. For an NTC thermistor of a certain size, the size of the filter capacitor allowed to be accessed is strictly required, and this value is also related to the maximum rated voltage. In power supply applications, the power-on surge is caused by capacitor charging, so the ability of NTC thermistor to withstand surge current is usually evaluated by the capacitance allowed to be accessed under a given voltage value. For a specific NTC thermistor, the maximum energy that can be withstood has been determined. According to the energy consumption formula of the resistor in the first-order circuit E = 1/2 × CV2, it can be seen that the allowable access capacitance value is inversely proportional to the square of the rated voltage. Simply put, the greater the input voltage, the smaller the maximum capacitance value allowed to be accessed, and vice versa.

2024/03/07

NTC thermistor 503NT-4-R25H42G resistance temperature comparison R-T table-huaju electronics

NTC thermistor 503NT-4-R25H42G resistance temperature comparison R-T table-huaju electronics

2024/03/07

Application of SCD Series NTC Thermistor in Power Amplifier Audio Power Supply-Huaju Electronics

In our audio amplifier, in order to achieve good performance indicators, we often use high-power power transformers and multiple large-capacity filter capacitors. Before starting up, these capacitors called "big ponds" are basically It is empty, the electricity stored in the capacitor is zero, and the voltage at both ends of the capacitor is also zero. We know that the voltage between the two poles of the capacitor can not be mutated, and the voltage at both ends of the capacitor is gradually increased from zero to the quota voltage when charging. At the moment of startup, the full voltage output from the transformer is rectified by the rectifier tube and added to both ends of the zero voltage capacitor. At this moment, the charging current output from the secondary coil of the transformer is extremely large, almost short-circuit current. In addition, the power amplifier uses a high-power transformer, and the excitation current at the moment of startup is also very large. These factors often cause the power overload fuse to blow at the moment of startup. In order to solve this problem, we usually add a start-up delay circuit in front of the transformer. At the moment of startup, several thermistors of more than ten ohms are connected in series on the primary incoming line of the transformer to limit the overload current caused by the charging of the large pond during startup. After the startup impact overload phenomenon has passed, the thermistors are short-circuited through the relay contacts that are turned on with delay, so that the AC mains power is directly connected to the primary of the transformer and normal power supply is restored.

2024/03/07

Selection of inverter starting resistor, selection of inverter pre-charge resistor-huaju electronics

The medium and small power general-purpose frequency converter is generally a voltage type frequency converter, which adopts the AC-DC-AC working mode. When the inverter is just powered on, because the filter capacitor capacity on the DC side is very large, the current is equivalent to a short circuit at the moment of charging, and the current will be very large. If there is no charging resistor between the rectifier bridge and the electrolytic capacitor, it is equivalent to a short circuit of 380V power supply directly to the ground, and the instantaneous rectifier bridge will blow up through infinite current. With the current limiting of the charging resistor, if there is no relay or other components, the charging resistor consumes a lot of power. For example, for a 22kW frequency converter, there is at least 45A of current on the PN terminal (DC bus). If there is a problem with the "control circuit" part (such as the quality of relays or thyristors, etc.), the charging resistor will be broken due to too much heat after the inverter runs for a while. Therefore, the charging resistor is connected in series in the charging circuit to limit the current at the moment of energization to protect some input circuit devices such as rectifiers. Some books are also called buffer resistors or starting resistors. SIEMENS 6SE701G variable frequency starting circuit as shown in the figure.