Capacitor (Polarized)
An electrolytic capacitor that stores charge between two plates. The positive terminal must always be at a higher potential than the negative terminal. Common in power supply filtering, bulk decoupling, and timing circuits.
Properties
| Property | Description | Default | Range |
|---|---|---|---|
| Capacitance | Charge storage capacity (F) | 100 µF | 1 pF – 100 000 µF |
| Voltage rating | Maximum safe voltage across the component (V) | 25 V | 1 V – 1 000 V |
| ESR | Equivalent series resistance — internal losses (Ω) | 0.1 Ω | 0.01 Ω – 10 Ω |
Simulation behavior
The capacitor charges toward the supply voltage through the series resistance in the circuit. The time constant τ = R × C determines how fast it charges. Once fully charged it blocks DC.
If the voltage across the capacitor exceeds the voltage rating, the component fails short (catastrophic breakdown). If the polarity is reversed (negative terminal higher than positive), failure occurs immediately.
ESR is modeled as a series resistance and contributes to power dissipation and output ripple in filter circuits.
Tips
- Always orient the positive terminal (marked with
+) toward the higher-voltage side of the circuit — reversed polarity causes instant failure in simulation. - Increase ESR to model an aged or low-quality capacitor and observe the effect on ripple in a power supply.
- Pair with an oscilloscope measurement on the output to visualize the RC charge/discharge curve.