Resistors control the voltage and current of an electronic circuit. The basic definition of a resistor is “any component which provides resistance in the way of current is called a resistor.” Electronic circuits use a wide variety of resistors. The function of resistors is classified into fixed and variable resistors. Fix resistors have only fixed resistance values, while you can manually vary the resistance of variable resistors. In variable resistors, multiple types are also present, like rheostat and potentiometer. We will discuss rheostat vs potentiometer in this article.
So, read the complete article better to understand these two types of papular variable resistors.
The first part of the article will explain what a resistor is and what the different types of resistors are. Almost every electronic circuit and many electrical circuits contain resistors. The resistance of resistors, as their name suggests, is crucial to the operation of most courses. Another definition of a resistor is “A passive electrical component with two terminals that limits or regulates the flow of current in any electrical or electronic circuit.”.
Purpose of a resistor
Resistors are primarily used to reduce current flow and lower voltage within a circuit. The resistor comprises copper wires wrapped around a ceramic rod, with an insulating paint coating the outer surface.
What are the different types of resistors?
There are mainly two types of resistors that are currently used in any electronic circuit. These types are mentioned below.
- Variable resistor
- Fixed resistor
Many resistors exist, but fixed resistors are most frequently used in electronics. Electronic circuits use these components to set the appropriate conditions. Resistance values are set at the design phase and shouldn’t have to be altered to “adjust” them. Fixed resistors can be classified into different types, which are mentioned below.
- Wire wound resistor
- Carbon film
- Metal film resistor
- Carbon composite
- Surface mount resistors
- Metal oxide film resistor
Another alternative is a variable resistor, which consists of a fixed resistor element tapped by a slider. Variable resistor gives three connections to the component, which are described below.
- Two connected to the fixed element in the electronic circuit
- The third is the slider. (For varying the resistance)
All three connections can be used to create a variable potential divider. The slider can be connected to one end of a resistor to provide a variable resistor.
All forms of control circuits utilize rheostat resistors and potentiometers. The term potentiometer describes a component consisting of a fixed resistor and a slider for providing a potential division from a voltage at the top. Rheostat resistors are essentially the same, except that they include a slider attached to the end of the resistor, resulting in a proper variable resistance. Now you will learn details about rheostat vs potentiometer.
Rheostat vs Potentiometer
To better understand rheostat and potentiometer, you must learn about these two components separately, as defined below.
The rheostat is a variable resistor that controls the current. Unlike other resistors, a resistor can change its resistance without interrupting a circuit. Only two connections are needed for a potentiometer, which has three terminals.
In comparison to potentiometers, rheostats consume a significant amount of current. Due to this, they are primarily wire wound resistors. An insulating ceramic core is wound with resistive wire, and the wiper slides over it.
In addition to controlling light intensity (dimmer), motor speed, heater speed, and oven temperature, rheostats are often used as power control devices. Due to their inefficiency, they are relatively ineffective. Power control applications now rely on switching electronics. In circuits, they are used as variable resistances for tuning and calibration. It is only necessary to adjust these situations during fabrication or circuit tuning (preset resistors). Often, trimpots, wired as rheostats, are used in these cases. Preset resistors with two terminals are also available.
You define a rheostat by following the definition.
“A rheostat regulates the current flow through a circuit by varying its resistance.”
The classification of rheostats
A rheostat can be classified as linear, rotary, or preset.
When used as a preset rheostat, a preset rheostat is typically used as a trimmer on a PCB. Often used in calibration circuits, these are small and compact. Three-terminal trimmers are sometimes used as two-terminal trimmers, but two-terminal trimmers are sometimes used as three-terminal trimmers.
Resistive lanes rotate around each other, which is why it is often used in power applications. A shaft that contains the wiper could be designed for these types. It consists of a sliding contact, which can move 34% of a circle over the terminal.
Rheostats are equipped with linear resistive lanes allowing the sliding terminal to move smoothly. Two permanent terminals are provided on the device, but only one is used, while the other can be connected to the slider. Laboratory applications frequently require the use of these devices.
In electrical terminology, a potentiometer is a three-terminal variable resistor that can be manually adjusted. Initially, the two terminals are connected to opposing ends of a resistor. In contrast, the third terminal is connected to a sliding contact moving over the resistive element called a wiper. Potentiometers work as variable resistance dividers.
Among other names, potentiometers are also known as potmeters or pots. The most common type of potmeter is a rotary potmeter with a single turn. A pool of this type is commonly used to control audio volume (logarithmic taper) and in many other applications. It is possible to construct potentiometers from various materials, including carbon composition, cermet, wirewound, conductive plastic, and metal film.
The motion of sliders in both potentiometers and rheostats provides considerable variation in the quantity required to perform their functions, although they monitor voltage and current. After reading this article, the difference between rheostats and potentiometers has become more apparent.