A voltage divider is one of the basic circuits used in electrical engineering. This is an important concept especially when more complex circuits are to be created. It allows engineers to analyze resistance and to optimize electronic devices. This circuit is one of the important applications of Ohm’s Law.
To give you a bit of a background, Ohm’s law stated that the current flowing through a conductor between two points is proportional to the potential difference across the same two points. This law is relevant in constructing a voltage divider.
Two of the important parts of a voltage divider is the circuit and the equation.
The circuit consists of the an input voltage (Vin), and two resistors (R1 closest resistor to the voltage and R2 closest to the ground). The Vout is the voltage drop (or divided voltage) across the R2 – which is the intended voltage that this circuit intends to create. It is the fraction of the voltage that was initially in the Vin.
The equation is a formula that will allow you to compute the Vout. By knowing this formula, you can manipulate the Vin to arrive at the right Vout that has to be produced by the voltage divider. The equation is as follows:
This equation simply states that the output voltage is directly proportional to the input voltage and ratio of the two resistors.
Voltage dividers are used in several ways in Electrical Engineering. One of the easiest applications to understand is in the Potentiometer. Also referred to as a pot, it is a variable resistor that is used to create an adjustable voltage divider. The pot consists of one resistor and a wiper. This wiper divides the resistor in two and is able to move to adjust the ratio of the two parts. The outside of the pot has three pins. Two of them are connected to each end of the resistor and the third is connected to the wiper. The two pins connected to the resistor are usually plugged to a voltage source (one ground and the other to the input voltage). The pin in the middle or the one connected to the wiper acts as the voltage divider.
