Before we use capacitors , we first need to understand the quality of the capacitors. At the same time, we also need to know roughly the size of the capacitors and find out whether the capacitors are suitable for connecting to a certain working circuit. Therefore, we should understand the common faults of the capacitors and the easy method to check the quality of capacitors.
There are four common failures of capacitors: breakdown (also called a short circuit), leakage, open circuit, and failure.
(1) Breakdown refers to a short circuit between two leads or pins of a capacitor, and the insulation resistance of the capacitor is zero.
(2) Leakage means that the insulation resistance of the capacitor is less than the normal value, and the insulation resistance of a normal capacitor should generally be more than several hundred kiloohms.
(3) Open circuit means that the internal leads and pole pieces of the capacitor have been disconnected.
(4) Failure means that the insulation resistance of the capacitor is significantly lower than the normal value or the capacitance has disappeared.
The actual working voltage of the capacitor is higher than its withstand voltage. The polarity of the electrolytic capacitor is reversed, the ambient temperature of the capacitor is too high, the humidity is too high, and the use time is too long. All of these are the reasons causing the above-mentioned failures of capacitors. Capacitors that already have one of the above-mentioned faults are generally unusable.
In the situations above, what methods can I use to check the quality of a capacitor?
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