An electrolytic capacitor is a type of capacitor. The metal foil is the positive electrode, and the metal oxide film close to the positive electrode is the dielectric. The cathode is composed of conductive materials, electrolytes and other materials.
Because the electrolyte is an important part of the cathode, the electrolytic capacitor is named after it. At the same time, the positive and negative electrolytic capacitors should not be connected wrongly!
Electrolytic capacitors can be divided into two types, one is aluminum electrolytic capacitors, and the other is tantalum electrolytic capacitors. There are three differences between the two. First of all, the medium is different. Tantalum electrolytic capacitors use metal tantalum as the medium, while aluminum electrolytic capacitors are naturally aluminum. Second, the performance is different. Tantalum electrolytic capacitors have excellent performance, wide operating temperature range, various forms, and excellent volumetric efficiency. . The third is the use of different capacitors, various shapes, and made into small and chip components suitable for surface mounting. Tantalum capacitors can be used in military communications, aerospace and other fields, tantalum capacitors are widely used in industrial control, film and television equipment, communication instruments and other products, but! It has a smaller capacity, is more expensive than aluminum capacitors, and has weaker voltage and current capabilities
Aluminum electrolytic capacitors can be divided into four categories: lead-type aluminum electrolytic capacitors; bullhorn aluminum electrolytic capacitors; bolt-type aluminum electrolytic capacitors; solid aluminum electrolytic capacitors.
What are the characteristics of electrolytic capacitors?
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 it can easily be tens of thousands of μf or even a few f (but not comparable to the electric double layer capacitance).
3 The price has an overwhelming advantage over other types, because the constituent materials of electrolytic capacitors are common industrial materials, such as aluminum and so on.
4 The equipment for manufacturing electrolytic capacitors is also common industrial equipment, which can be produced on a large scale with relatively low cost.
The role of electrolytic capacitors
1. DC blocking: The function is to prevent DC from passing and allow AC to pass.
2. Bypass: (also called decoupling) provides a low-impedance path for some parallel components in the AC circuit.
3. Coupling: As a connection between two circuits, allowing AC signals to pass through and be transmitted to the next circuit
4. Filtering: This is very important for DIY. The capacitors on the graphics card basically do this.
5. Temperature compensation: In view of the impact of other components' insufficient adaptability to temperature, compensation is made to improve the stability of the circuit.
6. Timing: The capacitor is used in conjunction with the resistor to determine the time constant of the circuit, and the time constant t=RC.
7. Tuning: System tuning for frequency-related circuits, such as mobile phones, radios, and televisions.
8. Rectification: Turning on or off a semi-closed conductor switching element at a predetermined time.
9. Energy storage: store electrical energy and release it when necessary. Such as camera flash, heating equipment and so on.