Resistor is a universal component in an electronic equipment. It is a critical electronic component in every circuit.
Resistor is a passive two-terminal electrical component that applies electrical resistance as a circuit element. In electronic circuits, resistors are used to reduce current flow, adjust signal levels, to divide voltages, and establish predetermined voltages or currents of an active elements, and terminate transmission lines.
Resistors are added to circuits, for them to complement active components such as op-amps, microcontrollers, and other integrated circuits. A resistor has two terminals, one connection on each end of the resistor, its terminals extend from the wavy lines or rectangles and it connects the rest of the circuit. The electrical resistance of a resistor is measured in ohms, it is named after Georg Simon Ohm. One ohm is equivalent to 1 volt of applied energy to push a one ampere of current.
The behavior of an ideal resistor is dictated by the relationship of the voltage, current, and resistance, which specified the Ohm’s Law. Ohm’s law proposed that the voltage across a resistor is proportional to the current, where the constant of proportionality is the resistance. However, the practical resistors can have an inductance and capacitance that can affect the relationship between the voltage and current in alternating current circuits. The total resistance of resistors connected in a series is the sum of their individual resistance values.
Resistors come in one of two termination-types, the through-hole or surface mount. These resistors can be standard, static resistor, a pack of resistors, or a special variable resistor.
Through-hole resistors have a long, pliable leads that can be inserted into a breadboard or hand-soldered into a prototyping board or printed circuit board. The long leads of the resistor usually require trimming, and it is bound to take up much more space than their surface-mount counterparts. The most common through-hole resistors come in an axial package.
Surface-mount resistors are tiny blank rectangles, which are terminated on either side with even smaller, shiny, silver, conductive edges. This kind of resistor is intended to be on top of a printed circuit board, it is soldered on the printed circuit board onto its mating landing pads.
As said, resistors exist in every electronic circuit. Resistors are the key component in LEDs, it ensures that the LEDs will not explode when the power is applied. The resistor that connects to the series to the LED makes the current flowing at a safe value. The characteristic value of the LED is typical forward voltage and maximum forward voltage that is required to light up the LED.
As resistors are a voltage divider, it veers the large voltages into a smaller voltage. A pull-up resistor is utilized when a direct current is deliberately made to flow to a microcontroller into a known state.
The failure rate of resistors in a properly designed circuit is low compared to other electronic components, damage can be accumulated to the resistor when overheating occurs when the average power delivered to the resistor greatly exceeds its ability to dissipate the heat.