Capacitor Calculator
Calculate total capacitance for series and parallel combinations. Enter 2-4 capacitor values and optional voltage to calculate charge, energy storage, and voltage distribution.
What is the formula for capacitors in series?
For capacitors in series, use 1/C_total = 1/C₁ + 1/C₂ + 1/C₃ + ... (reciprocal formula, like resistors in parallel). Total capacitance decreases. For two capacitors: C_total = (C₁ × C₂)/(C₁ + C₂). Voltage divides across capacitors.
What is the formula for capacitors in parallel?
For capacitors in parallel, total capacitance is the sum: C_total = C₁ + C₂ + C₃ + ... (like resistors in series). Total capacitance increases. Voltage is the same across all parallel capacitors, and charge sums up.
How do I calculate energy stored in a capacitor?
Energy stored in a capacitor is E = ½CV², where C is capacitance (Farads) and V is voltage. Also E = ½QV or E = Q²/(2C), where Q is charge. Energy is stored in the electric field between plates.
What is the relationship between charge, capacitance, and voltage?
The fundamental capacitor equation is Q = CV, where Q is charge (Coulombs), C is capacitance (Farads), and V is voltage (Volts). Capacitance is the ratio of charge stored to voltage applied: C = Q/V.
Why do capacitors in series decrease total capacitance?
In series, the same charge Q appears on all capacitors, but voltage adds: V_total = V₁ + V₂ + ... Since C = Q/V, more voltage for same charge means less capacitance. Series connection increases effective plate separation, reducing capacitance.
What are common capacitor units?
Farad (F) is the SI unit. Common units: microfarad (µF) = 10⁻⁶ F, nanofarad (nF) = 10⁻⁹ F, picofarad (pF) = 10⁻¹² F. Typical values: power supply filtering (100µF-1000µF), coupling (1µF-10µF), RF circuits (1pF-100pF).
How long does a capacitor take to charge or discharge?
Capacitor charging/discharging follows exponential curve with time constant τ = RC (resistance × capacitance). After 5τ, capacitor is ~99% charged/discharged. Voltage: V(t) = V₀(1 - e^(-t/τ)) for charging, V(t) = V₀e^(-t/τ) for discharging.
What is the difference between capacitance and capacity?
Capacitance (measured in Farads) is ability to store charge per volt: C = Q/V. It's a property of the capacitor geometry and dielectric. Capacity often refers to energy storage capability. Don't confuse with battery capacity (Ah or Wh).
Can capacitors be used for power storage like batteries?
Yes, but differently. Capacitors: fast charge/discharge, millions of cycles, low energy density, constant voltage. Batteries: slow charge/discharge, limited cycles, high energy density, stable voltage. Supercapacitors bridge the gap. Use capacitors for short-term, high-power applications.
What happens if I exceed a capacitor's voltage rating?
Exceeding voltage rating can cause dielectric breakdown - the insulator between plates fails, creating a short circuit. This can destroy the capacitor, sometimes violently (especially electrolytics). Always use capacitors rated at least 1.5-2× your maximum circuit voltage.
How do I calculate voltage across each capacitor in series?
In series, charge Q is same on all. Use V = Q/C for each. Voltage divides inversely proportional to capacitance: V₁/V₂ = C₂/C₁. Smaller capacitance gets larger voltage. Total voltage: V_total = V₁ + V₂ + ... = Q(1/C₁ + 1/C₂ + ...)
What are typical applications for capacitor calculations?
Applications: power supply filtering, energy storage, timing circuits, AC coupling, decoupling, motor starting, power factor correction, audio crossovers, flash photography, camera flashes, defibrillators, pulsed lasers, and EMI suppression.