https://supremetechinnovation.websites.co.in/RC CIRCUIT (Resistor-Capacitor circuit).
TIME CONSTANT (Delay)
In our last tutorial we saw how capacitor is being charged and discharged, how a large value capacitor can serve as an auxiliary power source and why it is never recommended to use a large capacitance at the input of a voltage regulator. In our last tutorial, we simply charge the capacitor directly from a power source without any resistance on its path.
Today, we are going to look at the second version or method of charging a capacitor which can be utilized to create something more meaningful such as introducing a delay. These we know as “Time constant” or simply an RC circuit. Time constant is the time taken for a capacitor to charge up to a certain percentage of the source voltage.
If you look at the “circuit 1” attached to this post, you will noticed that unlike our previous tutorial, the capacitor has a resistor attached to one of its end and then to the positive terminal. This resistance is one of the determining factor that causes the delay as the capacitor will not instantly charge up but will be at the mercy of the resistor. What we mean here is that since resistor opposes current flow, introducing it in the charging path of a capacitor will instantly limit the quantity of current a capacitor needed to charge up quickly. As a result, the capacitor will take a longer time to charge fully or discharge fully, thus creating a delay.
Time constant (T) is a product of capacitance (C) and resistance (R). Mathema
