Q:Does anyone know the difference between the stray inductance of the capacitor and the parasitic inductance?

In the design of high-speed digital circuits, the parasitic inductance of the vias is often more harmful than the parasitic capacitance. Its parasitic series inductance will weaken the contribution of the bypass capacitor, reducing the filtering efficiency of the entire power system. We can use the following formula to simply calculate a parasitic inductance of a vias:

Q:How to judge the capacitor is good or bad?

Due to the amplification of the composite transistor, the measured capacitance of the charge and discharge process to be amplified, so that the multimeter pointer increase the amplitude, so easy to observe. It should be noted that: in the test operation, especially in the measurement of small capacity capacitance, it is necessary to repeatedly change the measured capacitance of the pin contact A, B two points, in order to clearly see the multimeter pointer swing.

Q:What kind of capacitance can be divided into?

The paper dielectric is made of two pieces of metal foil, made of very thin capacitor paper, rolled into a cylindrical or flat cylindrical core, and then sealed in a metal shell or insulating material (such as paint, ceramics, glass glaze, etc.) production. It is characterized by a smaller size, capacity can be done bigger. But there are inherent inductors and losses are relatively large, suitable for low frequency.

Q:What is the principle of capacitance isolation?

When the capacitor is connected to the DC circuit, there will be a brief charging process. When the positive and negative plates are filled with charge (when the voltage across the capacitor is equal to the supply voltage), there is no current and then flow, so the capacitor is isolated DC current

Q:Is the capacitor attached to the carbon foil positive?

Electrolytic capacitors of the positive plate with aluminum foil, immersed in the electrolyte for anodic oxidation treatment, aluminum foil surface will produce a layer of aluminum oxide film, the thickness is generally 0.02 - 0.03μm. This layer of oxide film is positive and negative insulation between the plates.

Q:On the ground resistance, what role the capacitor

The capacitor used in the bypass circuit is called the bypass capacitor. If the signal is removed from the signal in the circuit, the bypass capacitor circuit can be used. According to the frequency of the removed signal, there is a full frequency domain (all AC signals ) Bypass capacitor circuit and high frequency bypass capacitor circuit.

Q:How to identify high voltage capacitors is good or bad

Test the resistance at both ends with a multimeter. If the use of a pointer multimeter, and most of the same capacitor, you can see the pointer from small to large a swing process. The difference is not the last return to infinity, but 10m. Inexperienced friends may think that the capacitor breakdown or leakage, in fact, not.

Q:Why does the circuit current gradually decrease when charging the capacitor?

For the ideal capacitor, when the capacitor is charged, as the voltage across the capacitor gradually increases, the charging current will gradually decrease until zero.

Q:Capacitance can pass high frequency resistance low frequency principle

This process of current flow will soon end, the specific length of time and the resistance of the circuit and the size of the capacitor, the larger the size of the product the greater the charging time, the shorter the contrary. After charging is complete, the voltage across the capacitor is equal to the size of the DC supply voltage

Q:Low voltage capacitor voltage 0.45 and 0.4 What is the difference between usage

0.45 capacitor used in the voltage level is high (for example, the transformer low voltage side voltage may reach 415V), with a tuned reactor (tuning reactor will increase the capacitor terminal voltage) situation; Note that the actual capacity of 0.45 capacitor nominal capacity (Actual voltage / 0.45) ^ 2 times;