Current Divider Calculator
Calculate how current divides between parallel resistors. Enter total current and 2-4 resistor values to determine current through each resistor and power dissipation.
What is the current divider formula?
For current divider with two parallel resistors: I₁ = I_total × (R₂/(R₁ + R₂)) and I₂ = I_total × (R₁/(R₁ + R₂)). Notice current through each resistor is inversely proportional to its resistance - smaller resistance gets more current. This is opposite to voltage dividers.
How does a current divider work?
A current divider splits total current between parallel resistors. Current takes paths of least resistance. Smaller resistance provides easier path, so more current flows through it. Total current equals sum of individual currents: I_total = I₁ + I₂ + ... All parallel resistors have same voltage across them.
Why does smaller resistance get more current?
By Ohm's Law: I = V/R. In parallel, voltage V is same across all resistors. Smaller R means larger I. Current distributes inversely proportional to resistance: resistor with half the resistance gets twice the current. Current seeks path of least resistance.
What is the difference between current divider and voltage divider?
Voltage divider: series resistors, voltage divides directly proportional to resistance. Current divider: parallel resistors, current divides inversely proportional to resistance. Voltage divider formula: V ∝ R. Current divider formula: I ∝ 1/R. Opposite relationships!
How do I calculate current through multiple parallel resistors?
For n parallel resistors: I_n = I_total × (1/R_n) / (1/R₁ + 1/R₂ + ... + 1/Rₙ). Or: I_n = I_total × (R_total/R_n), where R_total is equivalent parallel resistance. Current through each is proportional to its conductance (1/R).
What happens if resistances are equal in current divider?
If all n resistors are equal (R₁ = R₂ = ... = Rₙ = R), current splits equally: I₁ = I₂ = ... = Iₙ = I_total/n. Example: 6A through three equal resistors gives 2A through each. Equal resistance means equal current distribution.
Can I use current dividers for current sensing?
Yes! Current dividers are used in shunt-based current sensing. A small shunt resistor carries known fraction of total current. Measure voltage across shunt, calculate current. Also used in ammeter design (most current bypasses meter through low-resistance shunt).
How does current divider relate to Norton equivalent?
Norton equivalent circuit uses current source with parallel resistance - this is a current divider! When you connect load to Norton equivalent, current divides between Norton resistance and load according to current divider rule. Essential for circuit analysis and simplification.
What is conductance and how does it relate to current division?
Conductance G = 1/R (Siemens, S). Current divides proportionally to conductance: I_n = I_total × (G_n/G_total), where G_total = G₁ + G₂ + ... This is often simpler than using resistances. Higher conductance (lower R) means more current.
Can current dividers handle high power applications?
Yes, but carefully! Each resistor must handle its power: P = I²R. In parallel, total power P_total = P₁ + P₂ + ... For load sharing (like parallel power resistors), equal resistances divide current and power equally. Ensure adequate power ratings for each resistor.
How accurate are current dividers?
Accuracy depends on resistor tolerances and temperature coefficients. For precision current division, use matched resistors (same tolerance, temp coefficient). Temperature changes affect resistances differently, altering current distribution. Use metal film or precision resistors for critical applications.
What are practical applications of current dividers?
Applications: current sensing shunts, ammeter design, load sharing in parallel circuits, LED current balancing, battery parallel charging, current mirrors in IC design, analog signal splitting, current measurement, and safety current bypass paths in high-current circuits.