A voltage divider circuit is a simple electronic circuit used to divide a voltage into smaller fractions. It consists of a series of resistors connected in series across a voltage source. The output voltage is taken from the connection point between the resistors. This configuration allows you to obtain a fraction of the input voltage as the output voltage, determined by the ratio of the resistor values.
The basic formula for calculating the output voltage (
out
V
out
) of a voltage divider circuit is:
out
=
in
×
2
1
+
2
V
out
=V
in
×
R1+R2
R2
Where:
in
V
in
is the input voltage (the voltage across the whole series of resistors).
1
R1 is the resistance value of the first resistor in the series.
2
R2 is the resistance value of the second resistor in the series.
To construct a voltage divider circuit, follow these steps:
Select Resistor Values: Choose suitable resistor values for
1
R1 and
2
R2. The ratio of these resistor values will determine the output voltage. If you want to divide the voltage evenly, you can choose
1
=
2
R1=R2. If you want a specific voltage division ratio, calculate the resistor values accordingly using the formula above.
Connect the Resistors: Connect
1
R1 and
2
R2 in series across the voltage source (
in
V
in
). The positive terminal of the source connects to one end of
1
R1, and the negative terminal connects to the other end of
2
R2.
Measure the Output Voltage: The output voltage (
out
V
out
) is taken from the connection point between
1
R1 and
2
R2. You can measure this voltage using a voltmeter or use it as needed in your circuit.
It's important to note that the output voltage of a voltage divider is sensitive to the load connected to it. If the load impedance is too low (e.g., when connecting the divider output to a low-resistance input), it can affect the accuracy of the voltage division due to a phenomenon called "loading." In such cases, a buffer amplifier or other techniques might be employed to mitigate this effect.
Voltage dividers find various applications in electronics, such as level shifting, sensor interfacing, biasing transistor circuits, and more.