Calculator Form
Example Data Table
| Example | Values | Unit | Voltage | Frequency | Expected Use |
|---|---|---|---|---|---|
| Filter bank | 10, 22, 47 | µF | 12 V | 1000 Hz | Compare storage and reactance |
| High voltage divider | 1, 1, 1 | µF | 300 V | 50 Hz | Check series voltage sharing |
| Timing circuit | 100, 220 | nF | 5 V | 500 Hz | Estimate RC time constant |
Formula Used
Parallel capacitance: Ceq = C1 + C2 + C3 + ...
Series capacitance: 1 / Ceq = 1 / C1 + 1 / C2 + 1 / C3 + ...
Charge: Q = C × V
Stored energy: E = 1 / 2 × C × V²
Capacitive reactance: Xc = 1 / (2πfC)
RC time constant: τ = R × C
Cutoff frequency: fc = 1 / (2πRC)
In a series network, charge is the same on each capacitor. Voltage divides by capacitance. Smaller capacitors get larger voltage. In a parallel network, voltage is the same across every capacitor. Charge divides by capacitance.
How to Use This Calculator
Enter capacitor values separated by commas, spaces, semicolons, or line breaks. Select the matching unit. Choose series, parallel, or compare both. Add voltage to calculate charge, stored energy, and voltage sharing. Add frequency to calculate reactance. Add resistance to estimate RC timing and cutoff frequency.
Use ESR when real capacitor losses matter. Use tolerance to see the possible minimum and maximum equivalent capacitance. After calculation, the result appears above the form and below the header. Use CSV for spreadsheet records. Use PDF for a printable summary.
Capacitor Network Design Guide
Why Series and Parallel Connections Matter
Capacitors are often combined to reach a target value. A single part may not match the needed capacitance. It may also lack the required voltage rating. Series and parallel networks solve these limits. They also change charge, energy, reactance, and timing behavior.
Parallel Capacitor Behavior
Parallel capacitors add directly. This makes the total capacitance larger. It is useful for smoothing, buffering, and energy storage. Each capacitor sees the same voltage. Current and charge split across the parts. Larger capacitors store more charge in the same parallel bank.
Series Capacitor Behavior
Series capacitors reduce the equivalent capacitance. This may seem wasteful at first. Yet series wiring increases voltage handling when parts are matched. The same charge flows through each capacitor. Voltage does not split equally unless capacitance values are equal. A smaller capacitor gets a larger voltage share.
Real Circuit Factors
Ideal formulas are useful. Real circuits need more checks. ESR creates heating and voltage loss. Leakage resistance affects long storage time. Tolerance changes the actual value. Temperature and aging can shift capacitance. High ripple current can stress parts. This calculator includes several practical fields for better planning.
Reactance and Timing
Capacitive reactance depends on frequency. A larger capacitance gives lower reactance. A higher frequency also gives lower reactance. This matters in filters, coupling circuits, and power supplies. RC time constant shows how quickly a capacitor charges or discharges through resistance. One time constant reaches about 63.2 percent during charging.
Safe Design Notes
Always compare calculated voltage sharing with capacitor ratings. Add margin for tolerance and transients. Use balancing resistors in high voltage series banks. Check polarity for electrolytic capacitors. Confirm ripple current and temperature ratings from the part data sheet. This tool supports planning, but final designs still need safe engineering review.
FAQs
What happens when capacitors are connected in parallel?
The total capacitance increases. Add all capacitance values together. The same voltage appears across each capacitor. Charge is shared based on each capacitance value.
What happens when capacitors are connected in series?
The equivalent capacitance becomes smaller than the smallest capacitor. The same charge appears on each capacitor. Voltage divides across the parts.
Why does a smaller series capacitor get more voltage?
In series, charge is equal. Since V = Q / C, a smaller capacitance needs a higher voltage for the same charge.
Can I mix different capacitor values?
Yes. The calculator accepts mixed values. Series voltage sharing should be checked carefully when values are different.
What is ESR?
ESR means equivalent series resistance. It represents internal loss. High ESR can cause heating, voltage drop, and poor ripple performance.
Why is frequency needed?
Frequency is needed for capacitive reactance. Reactance shows how strongly the capacitor resists alternating current at that frequency.
What does tolerance range mean?
Tolerance range estimates possible low and high equivalent capacitance. It uses the entered percentage as a simple worst case.
Can this calculator replace a data sheet?
No. Use it for calculations and planning. Always confirm voltage, temperature, ripple current, polarity, and safety limits from the capacitor data sheet.