The electrical gadget that produces light by using electricity. The resistor (R) is used to limit the amount of current flowing through the circuit. Variable resistance, commonly known as the rheostat, is used to control the quantity of current flow by raising or lowering the resistance to current flow. This allows very small amounts of power to be controlled easily.
Resistors come in many different sizes and shapes. They are used to reduce current flow in circuits such as lamps, motors, and heaters. Too much resistance in a circuit will cause it to fail. Too little resistance and current will flood through the circuit, causing it to malfunction or destroy itself.
Variable resistors consist of two parts: a wiper and a resistive element. The wiper is a metal strip that slides back and forth across the surface of the resistive element. As the wiper moves across the surface of the resistive element, it causes current to follow one path or another. By carefully choosing the width of the wiper, the resistance of the device can be adjusted up or down.
There are three types of variable resistors: slide, tilt, and dial. Slide and tilt type variable resistors have their wiper arms that move along a curved surface. Dial type variable resistors have their wiper arms that rotate around a central point. Which type you get depends on what kind of look you want to give your project.
The brightness of a bulb is affected by its current. The brighter the bulb, the higher the current. A variable resistor allows you to raise the current from zero to maximum. Variable resistors are also used to control motor speed. On motors up to about 100 watts, a standard resistor can be used; for larger motors, a variable one is necessary.
The most common type of variable resistor is the rotary knob. It consists of an iron core with multiple plastic or rubber bands wrapped around it. Each band has two ends: one fixed and one free to move back and forth along the length of the core. By moving the free end of each band back and forth along the length of the core, you can change the resistance across the terminal posts connected to it. The more bands there are on the core, the greater the range of resistance values available. For example, a six-band core can produce a resistance as low as 1 ohm and as high as 16 ohms.
There are three types of rotary knobs: single-throw, double-throw, and center-off. With single-throw knobs, if you turn them counterclockwise, the resistance increases; if you turn them clockwise, the resistance decreases. Double-throw knobs work like single-throw ones, but they can be set to any resistance between their minimum and maximum values.
A light bulb, while not a typical resistor, behaves similarly to one. A resistor is an electronic component that restricts the passage of electrons. When electrons pass through a resistor, they encounter "resistance," and most of their energy is converted into other types of energy, such as heat. The rest goes on to the next circuit element.
The resistance of a resistor determines how much power it will draw when current is passed through it. More importantly, though, is what type of resistor it is. There are two main categories of resistors: passive and active.
Passive resistors are used for voltage division or current limitation. A series of different values of resistance stacked together creates a unit value resistor. For example, a 250-500-750-1000 milliohm (mho) resistor would create a total resistance of 1 megohm (1 million ohms).
Active resistors need electricity to work; they don't just rely on surface area coverage by conductive material to be effective. However, they do require more effort to construct than passive ones. Active resistors can be divided up into three sub-categories: bipolar junction transistors (BJTs), field effect transistors (FETs), and thyristors.
BJTs are commonly used as amplifiers in audio equipment and have several advantages over FETs. The most important is size.
In dim lighting, rheostats are used to control the intensity of the light. When we raise the rheostat's resistance, the flow of electric current through the light bulb diminishes. As a result, the brilliance of the light reduces. In very low-power applications where only a few watts are needed, a resistor can be used in place of a rheostat. The resistor would need to be large enough to handle the desired load current.
However, for most household uses, a rheostat is preferred because it can be easily controlled from one side. A knob is attached to the body of the rheostat to turn the power on and off. As you increase the resistance, more power is required to turn the knob. So if you were to keep turning the knob, the resistance would have to be increased constantly to maintain the same level of brightness.
In conclusion, as the resistance of the rheostat increases, so does the power consumption of the lamp. This means that more frequent adjustments will be necessary to maintain the desired level of illumination.