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Dingfeng Capacitor---Electrolytic Capacitor Electric Parameters

Issue Time:2016-06-15

Here mainly refers to the aluminum electrolytic capacitor, electrolytic capacitor of the basic electrical parameters include the following five:

1, the capacitance
Electrolytic capacitor of capacitance values, depending on the impedance of the work under ac voltage at the present.So the capacitance value, that is, ac capacitance value, as the working frequency, voltage and measuring method.In standard JISC 5102 regulation: aluminum electrolytic capacitor of capacitance measurement condition is in the frequency of 120 hz, the biggest
Current voltage is 0.5 Vrms, DC bias voltage is 1.5 ~ 2.0 V conditions.Can assert that the aluminum electrolytic capacitor capacity decreases with the increase of frequency.
2, loss tangent value Tan delta
In the equivalent circuit of capacitor, the equivalent series resistance ESR with capacitive reactance 1 / C ratio of omega called Tan delta, the ESR value is calculated under 120 hz.Obviously, Tan delta increased with the increase of frequency measurement, along with the decline of measuring temperature increase.
3, impedance Z
Under specific frequency, hinder the alternating current through the resistor is called impedance (Z).The equivalent circuit of capacitance, inductance and capacitance value are closely related, and also has relations with the ESR.
[the ESR Z =) ^ 2 + (XL - XC) ^ 2)
Type, XC = 1 / C = 1/2 omega PI fC
XL = L = 2 PI omega fL
Capacitance of capacitive reactance (XC) in low frequency range with the increase of frequency reduced gradually, increase frequency reaches medium frequency range reactance (XL) have fallen to the ESR value.When the range of frequency to high frequency impedance (XL) have become a dominant, so the impedance is increased with the increase of the frequency increase.
4, leakage current
Capacitor medium greatly hinder the role of direct current.However, due to the aluminum oxide film medium with electrolyte, when the applied voltage, the oxide film formation and repair of produce a small called leakage current.Usually, the leakage flow increases with the increase of temperature and voltage.
5, ripple current and ripple voltage
In some information, both called "ripple current" and "ripple voltage", is actually ripple current, ripple voltage.Meaning is the capacitor are tolerated ripple current/voltage value.The relationship between them and the ESR closely, can be expressed in the following formula:
Urms = Irms * R
Type of Vrms said ripple voltage, Irms said ripple current, capacitance of the ESR R said

By visible on, when the ripple current increases, even in the case of the ESR remain unchanged, the ripple voltage will be doubled.In other words, when the ripple voltage increases, the ripple current also increase, this is also requires capacity have lower ESR value.Fold after joining ripple current, capacitance due to the internal equivalent series resistance (ESR) cause fever, which affects the service life of the capacitor.In general, ripple current is proportional to the frequency, so the low frequency ripple current is low.

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