A current divider circuit is an electrical circuit configuration used to split a single current into multiple branches, each with a different resistance. The goal of a current divider is to distribute the total current flowing into the circuit among these branches in proportion to their respective resistances. This principle is based on Ohm's law, which states that current (I) is directly proportional to voltage (V) and inversely proportional to resistance (R), given by the formula:
=
I=
R
V
In a current divider circuit, the total current entering the circuit (I_total) is divided into two or more currents flowing through separate branches, which can be calculated using the following formula for each branch:
branch
=
total
×
other branches
branch
I
branch
=
R
branch
I
total
×R
other branches
Where:
branch
I
branch
is the current flowing through the specific branch.
total
I
total
is the total current entering the circuit.
branch
R
branch
is the resistance of the branch in question.
other branches
R
other branches
is the combined resistance of all other branches excluding the one being calculated.
It's important to note that the current divider rule assumes that the voltages across the branches are the same (i.e., the circuit is connected in parallel). This rule holds true when the impedance of the branches is purely resistive and there is no reactance (e.g., capacitance or inductance) involved.
One practical application of current dividers is in voltage regulators. In these cases, a current divider can be used to supply a specific current to a load while distributing the excess current through a bypass resistor to maintain a stable output voltage.
To summarize, a current divider circuit allows you to split an incoming current into multiple branches, with each branch receiving a proportion of the total current based on the ratio of its resistance to the sum of the resistances of all branches.