A voltage divider circuit is a simple electronic circuit used to divide a given input voltage into smaller fractions. It consists of two resistors connected in series between the input voltage source and the ground. The voltage across a specific point in the resistor network can be calculated using Ohm's law (V = I * R) and the voltage division formula:
out
=
in
×
2
1
+
2
V
out
=V
in
×
R
1
+R
2
R
2
Where:
out
V
out
is the output voltage you want to obtain.
in
V
in
is the input voltage applied to the circuit.
1
R
1
and
2
R
2
are the resistances of the two resistors in the circuit.
To construct a voltage divider circuit, follow these steps:
Select Resistors: Choose two resistors with the desired resistance values. The ratio of their resistances will determine the output voltage division. Keep in mind that the total resistance (
1
+
2
R
1
+R
2
) should not be too low, as it could draw excessive current from the source and impact the accuracy of the division.
Calculate Output Voltage: Decide on the output voltage you want to achieve and calculate the required ratio of the resistor values using the voltage division formula. For example, if you want to divide the input voltage by half,
1
R
1
and
2
R
2
should be equal.
Connect Resistors: Connect the two resistors in series. One end of
1
R
1
connects to the input voltage source, while the other end connects to one terminal of
2
R
2
. The other terminal of
2
R
2
connects to ground.
Measure Output Voltage: The voltage across
2
R
2
(between the connection point of
1
R
1
and
2
R
2
and ground) is the output voltage
out
V
out
. You can measure this voltage using a voltmeter.
Account for Load: If the load connected to the output affects the circuit, make sure to consider its impedance when selecting resistor values. High load impedance won't significantly affect the voltage division, but low load impedance can cause errors in voltage division.
Voltage divider circuits are commonly used in various applications, such as setting reference voltages, sensor interfacing, biasing transistors, and more. However, they have limitations, including sensitivity to changes in load impedance and a reduced ability to provide large divisions without significant current consumption.