Resistanskomponenter
Resistanskomponenter, commonly known as resistors, are passive electronic components that provide electrical resistance in a circuit. Their primary function is to limit current flow and control voltage levels. Resistors are fundamental building blocks in virtually all electronic devices. They are manufactured in various shapes, sizes, and materials, each suited for different applications and power ratings. Common types include carbon composition, carbon film, metal film, and wirewound resistors. The value of a resistor is measured in ohms (Ω). This resistance value is typically indicated on the component itself through a color code or printed numerical markings. Resistors dissipate electrical energy as heat, and their power rating, measured in watts (W), determines the maximum amount of power they can safely handle without damage. Key parameters for resistors include their nominal resistance, tolerance (the permissible deviation from the nominal value), and temperature coefficient (how much their resistance changes with temperature). Beyond simple resistance, some specialized resistors exhibit unique properties. Thermistors change resistance significantly with temperature, while photoresistors alter their resistance based on light intensity. Varistors are used for surge protection, and potentiometers and rheostats act as variable resistors, allowing for adjustable resistance.