The best and probably most typical way to differ resistance in an electrical circuit is through the use of a variable resistor – also known as a rheostat. Rheostats are two way variable resistors that often is able to deal with much higher and more powerful voltages and currents.
In this way, your rheostat can outperform a standard variable resistor and provides additional levels of safety that were previously not possible. When dealing with circuits, electricity, and wiring, investment in a quality rheostat adds a layer of safety that is of paramount importance when dealing with modern electronics.
First off, what does a rheostat actually look like? Generally, these devices are cylindrical in shape and have two ends for the connections they support. When constructed and assembled, these devices are made with resistive wire that is shaped for forming a toroid coil with a wiper crossing across the upper area of the toroid. This allows sliding to occur from one turn of the wire to the next.
A rheostat is sometimes designed using resistance wire that is wound on a heat-stable shape with a slider. This slider can be made from several metal indentations that grip to portion of the turns of resistance wire.
The indentations, or fingers, are the key part of this device, and can be moved across the resistance coil via an adjuster on the rheostat itself; which allows the tapping point of the device to be changed. While some may claim that rheostats could be used as variable potential dividers, they are most commonly and safely used as duel variable resistors.
Rheostats can also come in a three-terminal setting, but they can also be utilized as a two-terminal device if not connected to the third terminal. This is relatively common, and connecting the wiper terminal to the 3rd or end of the resistance track that isn’t used is a great idea since it decreases the variation of resistance on the track.
Simply put the simpler the better and don’t use terminals you do not need! A rheostat is a great way to link up multiple circuits and be safe in the process. Whether you are using a two or three terminal setup, properly knowing how to operate and use a rheostat can allow for solid electrical connections that do not threaten anyone’s safety.
We’re continually adding information to this site. For now, we will leave you with a couple rheostat related videos below to give you an introduction to the different types and applications. Enjoy!
Wikipedia has been used as a source in this article: http://en.wikipedia.org/wiki/Rheostat#Rheostat.