Resistors can be mainly divided into the following types:
1.Fixed resistor:
Carbon film resistor: Depositing a layer of carbon film on a ceramic substrate is cost-effective and suitable for applications such as power circuits and simple amplifier circuits that do not require high accuracy.
Metal film resistor: A layer of metal film is deposited on a ceramic substrate by vacuum evaporation or sputtering, which has the characteristics of high precision, low temperature coefficient, and good stability. It is commonly used in high-precision measurement circuits.
Wire wound resistor: using resistance wires such as copper wire and manganese copper wire wound on the insulation skeleton, suitable for high-power and high-precision circuits.
Cement resistance: The resistance wire is wound around a non alkaline heat-resistant ceramic piece, and protected and fixed with heat-resistant, moisture resistant, and corrosion-resistant materials on the outside. It is commonly used in circuits that require high power, such as power supply and motor control.
2.Variable resistor:
Potentiometer: It changes the contact position between the sliding arm and the resistor by rotating or sliding, and is commonly used in circuits that require continuous adjustment such as volume and brightness adjustment.
Variable resistor: designed for regulating larger currents and power, suitable for motor speed control and electric furnace temperature control.
3.Special resistance:
Thermistors: including positive temperature coefficient (PTC) and negative temperature coefficient (NTC) thermistors, used for overcurrent protection, temperature compensation, and temperature measurement, respectively.
Photoresistor: made of semiconductor materials such as cadmium sulfide or cadmium selenide, the resistance value changes with the intensity of light, and is commonly used in light controlled switches and light intensity measurements.
Definition and basic characteristics of resistance:
Definition: The obstruction of current by a conductor is called resistance, usually represented by the letter R and measured in ohms (Ω).
Basic characteristics: Different conductors have different hindering effects on current, and resistance is a property of the conductor itself. The greater the resistance of a conductor, the greater its hindrance to current flow.
