The method for measuring the resistance of the glaze and the resistor indication
2025-12-12
Resistor
Resistance is a linear element at both ends. The ideal element model (in line with Ohm's Law) is a device that consumes electrical energy and converts it into heat. The resistance coating is an inherent property of conductors. For different signals, both AC and DC signals can pass through the resistor. The physical quantity measured to determine the influence of temperature on the resistance is the temperature coefficient. The resistance value of the actual resistor element is generally related to temperature and is defined as the percentage change in resistance value for every 1℃ increase in temperature.
Actual resistance equivalent model
Generally speaking, the lead inductance and inter-terminal capacitance of actual resistors are not very ideal. There are always some parasitic inductance and capacitance present. When the glazed resistors are used in high-frequency applications, these parasitic factors cannot be ignored.
Resistor
Resistors are the most widely used components in electronic circuits. Their main functions in the circuit include dividing currents, limiting currents, and distributing voltages, among others. Together with other components, they form some functional circuits. Ordinary carbon film resistors or metal film resistors can be simulated as linear resistors under constant temperature conditions. The voltage and current values are limited within the rated range. If the voltage or current exceeds the specified value, the resistor will overheat, violate Ohm's law, and even burn out.
Classification of resistors
1 Winding resistors: General-purpose winding resistors, Precision winding resistors, High-power winding resistors, High-frequency winding resistors, Enamel-coated resistors;
2. Film resistors: Carbon film resistors, metal film resistors, metal oxide film resistors, chemical deposition film resistors, glass glaze film resistors, metal nitride film resistors
3 Solid resistors: Inorganic synthetic solid carbon resistors, organic synthetic solid carbon resistive enamel resistors;
4. Resistors: Varistors, thermistors, phototransistors, force sensors, gas sensors, humidity sensors;
Method for marking the resistance value of resistors
1. Direct marking method: On the surface of the resistor, mark the resistance value with numbers and unit symbols. The allowable error of the glazed resistor can be directly expressed as a percentage. If there is no deviation on the resistor, it is ±20%.
2. Character symbol method: The nominal resistance value is represented by a combination of Arabic numerals and character symbols, and the allowable deviation is also indicated by character symbols. The number before the symbol represents the integer resistance value, followed by the first and second decimal resistances; the character symbol following represents the allowable error.
3. Digital Method: The nominal value is marked with three digits from left to right on the resistor position. The first two digits represent the effective value, and the third digit is the index, which is the number of zeros. The unit is the ohm value typically expressed in text symbols.
4. Color Coding Method: Different colored bands or dots are used on the surface of the resistor to mark the nominal resistance value and the allowable deviation. Most resistors abroad adopt the color coding method. For more information on coated resistors, please visit Fourchuang Electric.
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