How to check electrolytic capacitors

The electrolytic capacitor is a indispensable component in most electrical circuits. They encounter as a sort of mini-battery and accrual a encounter from a power supply which is then distributed upon request when required by other components in the circuit. Often, when a single capacitor malfunctions, the entire circuit stops working. Checking capacitors is a good place to start when troubleshooting. This can easily be curtains when a digital multimeter that is talented of reading high voltage values. For other tests, you may need an ohmmeter or device that can play-act capacitance.

Use a little piece of drifting wire to jump the two terminals of the capacitor and release any stored voltage. keep the capacitor by its insulated body and grab the wire when a pair of pliers, touching one stop of the wire when each to one of the capacitor’s leads. Although the computer graphics stored in most little capacitors is not more than ample to cause a serene shock, you should avoid touching the wires or bare wire even if discharging.

For large capacitors that play-act on top of 400uF or those that are allowance of a power supply chain and carry high voltage, use a high wattage, high omnium resistor, such as a 2K Ohm/25 watt resistor, to release the capacitor. keep the resistor in place for several seconds to make definite the capacitor is sufficiently discharged.

Connect the negative (black) dissect to the black jack upon the digital multimeter. link up the red (positive) dissect to the red jack marked to right of entry the resistance. incline the meter knob to a high ohms setting, amongst 10K and 1M ohms.

Touch the red dissect to the definite guide of the capacitor, and the black dissect to the negative lead. A capacitor is a directional component, as a result it’s important to correctly identify the definite and negative leads. Typically, these are marked when an arrow indicating the giving out of current flow through an electrolytic capacitor, when the tip of the arrow pointing toward the negative lead.

Look at the meter display. If the capacitor is in good keen order, it will play-act zero, then influence to infinity and stop there. If the meter reads zero and there is no change, the capacitor is not holding a encounter and is as a result not working.

Perform the same operation when a capacitor of a same rating that works, to qualify the results.

Tips

If the meter settles to a dwindling under infinity after rising from zero, there may be a voltage leak in the capacitor. To state this, compare the results when those of a same capacitor that is known to work.

Warnings

Always unconditionally release the capacitor past testing, as failure to do as a result may cause damage to the capacitor or the multimeter.