In physics, resistance is used to represent the magnitude of a conductor's resistance to current. The greater the resistance of a conductor, the greater its resistance to current. Different conductors generally have different resistance, which is a characteristic of the conductor itself. A resistive component is an energy consuming component that hinders current flow.
The resistance value of a resistive component is generally related to temperature, material, length, and cross-sectional area. The physical quantity that measures the influence of temperature on resistance is the temperature coefficient, which is defined as the percentage of change in resistance value for every 1 ℃ increase in temperature.
Resistance is the most commonly used component in all electronic circuits.
Resistance unit
The resistance of a conductor is usually represented by the letter R, and the unit of resistance is ohms, abbreviated as ohms. The symbol is Ω, and 1 Ω=1V/A. The larger units are kiloohms (k Ω) and megaohms (M Ω) (megaohms=one million, or one million).
Resistor, commonly referred to as "R", is the most commonly used component in all electronic circuits. The main physical characteristic of a resistor is to convert electrical energy into thermal energy, which can also be said to be an energy consuming component. Current passing through it generates internal energy. Resistors usually play a role in dividing and diverting voltage in circuits, and for signals, both AC and DC signals can pass through resistors.
K Ω (kiloohms), M Ω (megaohms), their conversion relationship is:
1T Ω=1000G Ω; 1G Ω=1000M Ω; 1M Ω=1000K Ω; 1K Ω=1000 Ω (i.e. one thousand steps)
Market conditions:
At present, in the global market share, Taiwan, Japan, Chinese Mainland and South Korea rank first, and Europe and the United States almost no longer produce. Almost all major manufacturers have established production bases in China. Famous Taiwanese manufacturers such as EVErhoMS, VIKING, YAGEO, and BGOSTAR, while Japanese companies include KOA, HOKURIKU, ROHM, and European and American companies such as VISHAY.
Brands commonly seen in the mainland market, such as EVEROHMS, VIKING, Yageo, and BGOSTAR.
Types of resistors:
Chip type: thick film chip resistance thin film chip resistance alloy chip resistance
Plug-in type: carbon film resistor, metal film resistor, metal oxide film resistor, cement resistor, winding resistor
Parameters of resistance:
Volume specification, power resistance value error, temperature coefficient (TCR), withstand voltage (V)
The function of resistance:
The main function is to hinder the flow of current, which is applied to current limiting, shunt, voltage reduction, voltage sharing, load and capacitor coordination filters, and impedance matching. The functions in the digital circuit include Pull-up resistor and pull-down resistance.
The function of resistors:
Load resistance, sampling resistance, shunt resistance, protection resistance, etc.
