A voltage divider circuit is a simple electronic circuit used to create a lower voltage from a higher voltage source. It consists of two or more resistors connected in series across a voltage source, and the junction between these resistors is taken as the output voltage. The output voltage is a fraction of the input voltage and can be calculated using Ohm's law and the voltage division principle.
The formula to calculate the output voltage (
out
V
out
) in a voltage divider circuit is:
out
=
in
×
2
1
+
2
V
out
=V
in
×
R
1
+R
2
R
2
Where:
out
V
out
is the output voltage across the second resistor (
2
R
2
).
in
V
in
is the input voltage supplied to the voltage divider.
1
R
1
is the resistance of the first resistor.
2
R
2
is the resistance of the second resistor.
Here's how you can design a voltage divider circuit:
Determine Input and Output Voltages: Decide on the input voltage (
in
V
in
) and the desired output voltage (
out
V
out
).
Choose Resistor Values: Calculate the ratio of
out
V
out
to
in
V
in
using the formula above. Then, select resistor values
1
R
1
and
2
R
2
that achieve this ratio. You can choose commercially available resistor values that come closest to the calculated values.
Calculate Resistor Ratio: Calculate the desired resistor ratio
2
1
R
1
R
2
based on the ratio of output to input voltage.
Calculate Resistor Values: Based on the desired resistor ratio, you can choose a suitable value for one resistor (e.g.,
1
R
1
) and then calculate the value for the other resistor (e.g.,
2
R
2
).
Assemble the Circuit: Connect the resistors in series across the input voltage (
in
V
in
), making sure that the junction between the resistors is the desired output voltage point (
out
V
out
).
Check and Adjust: After assembling the circuit, you can measure the actual output voltage using a multimeter and adjust the resistor values if needed to fine-tune the output voltage.
Voltage divider circuits are commonly used in electronics for various purposes, such as generating reference voltages, level shifting, sensor interfacing, and biasing components in amplifiers. It's important to note that voltage dividers have limitations, including sensitivity to load changes and current consumption, which can affect the accuracy of the output voltage.