High-frequency low-impedance electrolytic capacitor High capacity per unit volume

The electrolytic capacitor is a type of capacitor. The metal foil is a positive electrode (aluminum or tantalum). The oxide film (alumina or tantalum pentoxide) that is in close contact with the positive electrode is a dielectric. The cathode is made of a conductive material and an electrolyte (electrolyte can be liquid or Solids) and other materials together, because the electrolyte is the main part of the cathode, so the name of the electrolytic capacitor.

At the same time, the electrolytic capacitor can't be connected incorrectly. Aluminum electrolytic capacitors can be divided into four categories: lead type aluminum electrolytic capacitors; horn type aluminum electrolytic capacitors; bolt type aluminum electrolytic capacitors; solid aluminum electrolytic capacitors. Below, the editor recommends a good quality electrolytic capacitor for your reference.

Features:

1. The capacitance per unit volume is very large, tens to hundreds of times larger than other types of capacitors.

2. The rated capacity can be very large and can easily be tens of thousands of μf or even a few f (but it cannot be compared with double layer capacitors).

3. The price is overwhelmingly superior to other types because the constituent materials of electrolytic capacitors are common industrial materials such as aluminum. The equipment for manufacturing electrolytic capacitors is also an ordinary industrial equipment, which can be produced on a large scale and the cost is relatively low.

Product principle:

Electrolytic capacitors are usually made of metal foil (aluminum/niobium) as the positive electrode, and the insulating oxide layer (aluminum oxide/niobium pentaoxide) of the metal foil is used as a dielectric. The electrolytic capacitor is divided into aluminum electrolytic capacitors and tantalum electrolytic capacitors by its positive electrode. Capacitors. The negative electrode of an aluminum electrolytic capacitor is composed of a thin paper/film or electrolyte polymer impregnated with an electrolyte liquid (liquid electrolyte); manganese dioxide is generally used as a negative electrode of a tantalum electrolytic capacitor. Because the electrolyte is used as a negative electrode (note the difference with the dielectric), the electrolytic capacitor is named.

Applications:

A polar electrolytic capacitor usually functions as a power supply filter, decoupling, signal coupling, time constant setting, and DC blocking in a power supply circuit or an intermediate frequency circuit or a low frequency circuit. Generally can not be used for AC power circuit, when used as a filter capacitor in the DC power circuit, the anode (positive) should be connected to the positive terminal of the power supply voltage, and the cathode (negative) should be connected to the negative terminal of the power supply voltage. , otherwise it will damage the capacitor.

Non-polar electrolytic capacitors are commonly used in speaker divider circuits, TV S correction circuits, and start-up circuits for single-phase motors.

Electrolytic capacitors are widely used in household appliances and various electronic products, and have a large capacity range, generally 1 to 33000 μF. The rated operating voltage range is 6.3 to 700V. The disadvantage is that the dielectric loss and capacity error are large (the maximum allowable deviation is +100%, -20%), and the high temperature resistance is poor, and the storage time is long and it is easy to fail.

The polarity of the electrolytic capacitor, observe the side of the electrolytic capacitor has "-" is negative, "+" is positive, if the electrolytic capacitor is not marked positive and negative, it can be judged by the length of its pin, long feet The positive electrode and the short electrode negative electrode.