Selection and application of an aluminum electrolytic capacitor (voltage treatment)

When the aluminum electrolytic capacitor is stored for a long time without applying voltage, the leakage current will increase and drift outside the specification. If the capacitor has been stored for a long time (usually more than 2 years), it should be checked to verify whether its leakage current is still within the specification. If the capacitance deviates from the specification, the leakage current of the capacitance needs to be restored to the specification range through the capacitive modification or voltage treatment.

Voltage treatment is also known as repair or re-aging. Its method includes applying rated voltage to the capacitor through a 1k Ω resistor for 30 minutes.

For the capacitors that have been transferred to the circuit, the entire circuit can be aged.

01. If the input voltage is adjustable or the charging power supply is variable, the operation steps are as follows:

Set the input voltage to a low value (about 1/2 of the rated voltage).

Apply voltage for 10 minutes.

Slowly increase the voltage until the rated voltage is reached.

Apply the rated voltage for 30 minutes.

02. When the input voltage is not adjustable, the following operation steps can be adopted:

Turn on the device.

Apply voltage for 30 minutes.

Monitor equipment performance during voltage processing.

03. When the aluminum electrolytic capacitor is not used, use the following test circuit and carry out the test through the following steps:

Equipment required:

DC power supply (adjustable if possible)

switch

voltmeter

1k Ω resistance

timer

Test circuit:

erection sequence:

Connect to the power supply through a switch.

Connect a 1k Ω resistor to the other end of the switch.

The other end of the resistor is connected to the anode or positive lead of the capacitor.

Connect a voltmeter to the resistance.

Perform the test:

Set the power supply to the rated voltage of the capacitor.

Turn on the power.

Turn off the switch and start the timer.

Apply voltage for 30 minutes.

During voltage processing, monitor the voltage at both ends of the resistor.

When the leakage current LC=V/1k Ω meets the specified leakage current of the capacitor, it indicates that the voltage treatment has been completed.

Generally, if the storage time of the capacitor is within 2 years in the temperature range of 5 ° C to 35 ° C, the capacitor can be used without voltage treatment. After voltage treatment, the capacitance can be stored for another 2 years. If the storage period exceeds an additional 2 years, the capacitor should be scrapped and replaced with a new element.