resistance
Resistance is a linear component with two ends, and the ideal component model (in accordance with Ohm's law) is a device that consumes electrical energy and converts it into heat. Glazed resistance is an inherent characteristic of conductors. For different signals, both AC and DC signals can be measured through resistance. The physical quantity of resistance affected by temperature is the temperature coefficient. The actual resistance value of a resistive element is generally related to temperature, 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 electrode capacitance of actual resistors are not ideal, and there may be some lead inductance and inter electrode capacitance to some extent. When applied to high-frequency applications by enamel resistors, these parasitic factors cannot be ignored.
resistor
Resistors are the most widely used components in electronic circuits, with the main functions of shunting, current limiting, voltage distribution, etc. Together with other components, they form some functional circuits. Ordinary carbon film resistors or metal film resistors can be simulated using linear resistors at a constant temperature, limited by the voltage and current values of the glaze resistor under rated conditions. If the voltage or current exceeds the specified value, the resistor will overheat, violate Ohm's law, or even burn out.
Classification of resistors
1. Wire wound resistor: Universal wire wound resistor, precision wire wound resistor, high-power wire wound resistor, high-frequency wire wound enamel resistor;
2 Film Resistors: Carbon Film Resistors, Synthetic Carbon Film Resistors, Metal Film Resistors, Metal Oxide Film Resistors, Chemical Deposition Films, Glazed Resistors, Glass Glazed Resistors, Metal Nitride Resistors
3 Solid State Resistors: Inorganic Synthetic Solid Carbon Resistors Organic Synthetic Solid Carbon Enamel Resistors;
4. Sensitive resistors: varistors, thermistors, photoresistors, force sensitive resistors, gas sensitive resistors, and humidity sensitive resistors;
Marking method for resistor resistance value
1. Direct marking method: Mark the resistance value on the surface of the resistor with numbers and unit symbols, allowing the glaze resistance error to be directly expressed as a percentage. If there is no deviation in the resistance, it is ± 20%;
2. Text symbol method: Use a regular combination of Arabic numerals and text symbols to represent the nominal resistance value, and the allowable deviation is also represented by text symbols. The number before the symbol represents the integer resistance, followed by the first and second decimal resistors; Indicate that incorrect text symbols are allowed;
3-digit method: The nominal value is marked with three digits from left to right on the number of resistor bits, with the first two digits being the effective value and the third digit being the index, which is the number of zeros, usually represented by text symbols as the unit of measurement;
4 Color code method: Mark the nominal resistance value and allowable deviation on the surface of the resistor with different color bands or dots. Most foreign resistors use color code method. Follow Sichuang Electric to learn more about glazed resistors.
