What is the physical significance of removing the mica medium in a capacitor

The amount of charge on the plates is reduced when the mica medium is removed in a capacitor, and the electric field strength between the plates.

No change. If the capacitor is always connected to a constant voltage DC power supply, the potential difference between the two ends of the capacitor.

unchanged, the dielectric constant after the mica medium is removed.

Decrease, and the change in capacitance and the change in electric field strength are judged by the change in the dielectric constant of the capacitor.

If the capacitor is connected to a constant voltage DC power supply, the potential difference between the two ends of the capacitor remains unchanged.

The medium of mica capacitors is mica sheets.

The electrodes are available in metal foil type and metal film type. Earlier mica capacitors consisted of metal foil or silver spraying on the surface of mica sheets to form electrodes, which were then laminated and impregnated and pressed into bakelite shells according to the required capacity.

Nowadays, most of the mica dielectric is coated with a layer of silver electrodes, and the core structure is stacked, and then it is encapsulated into a housing to form a capacitor. The shell has ceramic shell, metal shell and plastic shell, and the commonly used plastic shell.

Relative permittivity, a physical parameter that characterizes the dielectric or polarization properties of a dielectric material. Its value is equal to the ratio of the capacitance of a capacitor of the same size made of ** material as a medium and a capacitor made of vacuum as a medium, and this value is also a representation of the material's power storage capacity. Also known as relative permittivity.

The relative permittivity of different materials at different temperatures is different, and capacitors or related components with different performance specifications can be made by using this characteristic. The substances that can produce polarization are collectively called dielectrics, which is really difficult to explain all at once, so it's best to go to the hard city and take a look.

Gate. The electrode closest to the cathode in a multipolar tube.

It has the shape of a fine wire mesh, or a spiral, and has the effect of controlling the strength of the current at the pole of the board, or changing the performance of the tube.

Capacitance. It is a physical quantity that characterizes the ability of a capacitor to hold an electric charge. The capacitance of a capacitor is called the capacitance of a capacitor by increasing the potential difference between the two plates of a capacitor by 1 volt.

Capacitors include fixed capacitors and variable capacitors, of which fixed capacitors can be divided into mica capacitors, ceramic capacitors, paper plastic film capacitors, electrolytic capacitors and glass glaze capacitors according to the dielectric materials used; Variable capacitors can also be glass, air, or ceramic dielectric structures.

Tantalum capacitors are polarized electrolytic capacitors (with a "+" symbol at the positive end) and cannot be reversed when used. Reverse polarity can increase leakage or may cause short circuits when used.

2.The circuits that cannot be applied are as follows: high-impedance voltage holding circuits; coupling circuits; time-constant circuits; Circuits where leakage current is affected; This is a circuit that increases the withstand voltage by connecting it in series.

3.Do not use more than the rated voltage, otherwise it may cause a short circuit.

4.It is necessary to limit the rapid charging or discharging. It is recommended to add a current-limiting resistor to the charging and discharging circuits to make the impulse current less than 20A.

5.In the design, the capacitance, withstand voltage, impedance, etc. of the capacitor should leave a certain margin to make it safer and more reliable.

6.Confirm that the temperature range used is within the operating temperature range of the capacitor. The supply current does not exceed the allowable ripple current, and when the allowable ripple current is exceeded, heat will increase inside the capacitor and reduce the service life.

7.It is recommended that the voltage applied by the capacitor is 90% of the rated voltage, if the rated voltage is greater than 10V, it is better to take 80% of the rated voltage; If the DC voltage is added to the alternating voltage, the peak voltage cannot exceed the rated voltage; If the total DC voltage is combined with the negative peak alternating voltage, no negative voltage is allowed.

Because the capacitor has such a danger, we should pay special attention to its instructions when using. The above precautions for tantalum capacitors, I hope it can help you. Shenzhen Sperite Technology Professional Electronic Components The company's official website has a lot of knowledge in this area, and you can learn about it.