Electrical parameters of Electrolytic Capacitor(I)

1. Capacitance value.

The capacitance of an electrolytic capacitor depends on the impedance it presents when it works at an AC voltage. Therefore, the value of the AC capacitance varies with the operating frequency, voltage, and measurement method. Standard JISC 5102 states that the capacitance of aluminum electrolytic capacitors is measured at a frequency of 120Hz, with a maximum alternating current.

The current voltage is 0.5 V RMSN DC bias voltage is 1.5 ~ 2.0 V. It can be asserted that the capacity of aluminum electrolytic capacitor decreases with the increase of frequency.

2. Tangent value of loss angle Tan δ.

In the equivalent circuit of capacitor, the ratio of series equivalent resistance ESR to capacitive reactance 1 / ω C is called Ta.

N δ, where ESR is calculated under 120Hz. Obviously Tan δ with the measured frequency.

Increases with the decrease of the measured temperature.

3. Impedance Z.

At a particular frequency, the resistance that blocks the passage of an alternating current is called an impedance. It's with electricity.

Capacitance and inductance in capacitive equivalent circuits are closely related to ESR.

Z = √ [ESR2 + (XL - XC)2 ]

XC = 1 / ω C = 1 / 2 π fC.

XL = ω L = 2 π fL.  

When the intermediate frequency range is reached, the reactance (XLL) is reduced to the value of ESR. Inductance XLL when the frequency reaches the high frequency range.

It becomes dominant, so the impedance increases as the frequency increases.