Electrical resistors play a central role in electrical engineering. Ultimately there is no electronic assembly that can do without them. Also known as ohmic resistance, it defines what electrical voltage is required to allow a certain amount of electrical current to flow through an electrical conductor. Even if the electrical resistance appears very simple in a first approximation, the components can be very complex.
Resistors come in a wide variety of designs and physical properties. Resistors in chip form belong to the SMD (Surface Mounted Device) types. They are designed as resistor networks for high voltage or high frequency applications. Resistors whose behavior changes depending on the voltage are called varistors. These voltage-dependent resistors are generally used as surge protection. Thermistors, on the other hand, are temperature-dependent. They are available with negative (NTC) or positive (PTC) characteristics.