What is a Dimmer Switch?
When you are furnishing a home, lighting should be one of your primary concerns. The function of the room should determine the type of lighting you want. If the room will be used for office work or reading, a high wattage bulb should be used. However, a bright, glaring light could be the last thing you want if you are hosting a romantic dinner for two. If your room is going to be used for multiple purposes, then you will also need varying amounts of light. The answer to this dilemma is the dimmer switch. With a dimmer switch, you can adjust the light to different levels by simply turning a knob or sliding a lever. Early dimmer switches operated with the variable resistor. A standard resistor is a poor conductor of electricity and offers a great deal of resistance to moving electrical charges. A variable resistor is made up of a piece of resistive material, a stationary contact arm, and a moving contact arm. With this design, the total resistance of the resistor can be varied by adjusti
In its oldest and simplest form, a dimmer switch is a variable resistor. A resistor is an electrical element or component that resists (or opposes) the flow of electrical current (the flow of electrons) in an electrical circuit. It is called variable because you can adjust the amount of resistance that it has. When a variable resistor is used in a circuit to vary the brightness of a lightbulb, you make the resistance greater when you want a dimmer light setting and you make the resistance smaller when you want a brighter light setting. Resistance is increased by increasing the length of the path of resistive material through which the electrons have to flow, and is decreased by decreasing the length of the path. Resistance is calculated in an electrical circuit, like the one below, through the use of Ohm’s law, and is measured in the units of ohms. Figure 1. This illustration shows a voltage source driving a current through a resistor in an electrical circuit. The three quantities—volt
