Withstand Voltage and Capacitance Decrease in Capacitor 

Film capacitors are widely used in electronic circuits because they have many excellent characteristics. But the capacitance and withstand voltage of film capacitors will decrease after a long period of use, which will seriously hinder the effect of use. So what are the factors for the reduction of capacitance and withstand voltage in film capacitors?

There are many factors that lead to the decrease in the capacitance of film capacitors, if the capacitor sealing is not tight enough, water vapor enters and leads to oxidation, which will cause the long-term instantaneous current to be too large, voltage too high, and it will trigger internal self-healing, leading to capacitance reduction. Working over-load for a long term will also lead to evaporation of metal plating, resulting in capacitance reduction.

In order to avoid the above situation leading to a decrease in film capacitor capacitance and withstand voltage, we need to make sure the manufacturing of the selected film capacitors is proper and the working condition is suitable for the film capacitors.

Thus, it is recommended to select a trustworthy manufacturer when purchasing film capacitors.JYH HSU(JEC) (or Dongguan Zhixu Electronics) not only has full models of ceramic capacitors with guaranteed quality, but also offers worry-free after-sales. JEC factories are ISO 9000 and ISO 14000 certified. Welcome to contact us: https://www.jeccapacitor.com

 

The Printing on the Safety Capacitor Housing

In switch power supply and electronic circuits, there is an electronic component that can protect the circuit, which is called safety capacitor.

 

The full name of the safety capacitor is the capacitor for suppressing electromagnetic interference of the power supply. If the external power supply is disconnected during use, the safety capacitor will quickly release the internal charge. At this time, touching with hands will not cause electric shock, which greatly protects personal safety. It complies with safety testing and safety certification, and its casing is printed with multi-national safety certification marks, so it is used in switching power supplies and circuits to protect circuits and human bodies, and protect the human body from current damage.

 

Safety capacitors are widely used in small household appliances, power supply products, electromechanical motors, LED lighting, portable chargers, etc.

 

Safety capacitors are common, but how can we know the information about safety capacitors when choosing? In fact, we can get the information we want to know through the printing on the safety capacitor housing. For example, the capacitance, capacitance tolerance, safety certification, etc. of safety capacitors can be obtained through the printing on the safety capacitor case.

 

The following picture is a safety Y capacitor branded as JEC (JYH HSU):

 

 

1. The Capacitance of Safety Capacitors

 

Safety capacitance range: 10pf~10000pF. Here, JEC's safety Y capacitor has a capacitance capacity of 4700pF.

 

2. The Safety Capacitor Capacitance Tolerance

 

In the process of capacitors, it is not guaranteed that the capacitance of each capacitor is consistent with the nominal value, and there is always a certain deviation, which is the capacitor capacitance tolerance. The capacitance tolerance of the capacitor is expressed as a percentage of J grade: ±5%, K grade: ±10%, M grade: ±20%, Z: -20% ~ +80%. Among them, the tolerance less than 5% can be called precision capacitors, while the general capacitors are mostly J, K, M grade.

 

The safety Y capacitor capacity tolerance of Zhixu JEC is M grade: ±20%.

 

3. Safety Capacitor Safety Certification

 

In order to protect the personal safety of consumers and protect their related interests, China has formulated some relevant regulations to standardize and reduce the appearance of inferior counterfeit safety capacitors that endanger personal safety. And it is stipulated that safety capacitors that have not been certified by safety regulations and electronic products that require safety certification cannot appear and cannot be sold on the market. Safety certification includes CQC in China, UL in the United States, ENEC in the European Union, VDE in Germany, KC in South Korea, etc.

 

JEC's safety Y capacitor has CQC, ENEC, VDE, UL, KC and other multinational safety certifications, saying that JEC's safety Y capacitor has passed the safety certification of many countries and can be sold, which also proves from the side that Zhixu electronic safety capacitors have good quality and quality assurance.

Welcome to visit our website: https://www.jeccapacitor.com/

 The Coupling and Decoupling Functions of Ceramic Capacitor

Ceramic capacitors are widely used in electronic circuits due to their advantages such as non-polarity, high temperature resistance, large specific capacitance, good moisture resistance, small dielectric loss, and high reliability. Ceramic capacitors are used in many places, and they play the role of coupling, decoupling, smoothing, and filtering in electronic circuits. Although the words coupling and decoupling are similar, the two functions are quite different in the circuit.

Coupling: In electronic circuits, coupling means connection, sending the upper level signal to the next level, sometimes the circuits cannot be directly connected, so electronic components need to be used for linking. Ceramic capacitors are used as the connection between the circuits, blocking the direct current, allowing the alternating current signal to pass and be transmitted to the next-level circuit.

Decoupling: Ceramic capacitors are installed on the power supply side of electronic products. In this circuit, ceramic capacitors can be used as energy storage capacitors to provide stable power supply for electronic products, and at the same time reduce the noise transmitted from components to the power supply terminal and reduce the interference of other components by noise.

Since active devices will generate high-frequency switching noise when switching, and this high-frequency switching noise will propagate along the power line, ceramic capacitors provide a low-impedance leakage path for high-frequency switching noise in the circuit and guide the noise to the ground, reducing and removing high-frequency switching noise to prevent high-frequency switching noise from interfering with the circuit.

The above is about the coupling and decoupling functions of ceramic capacitors in circuits. Select a reliable manufacturer when purchasing electronic components can avoid a lot of unnecessary trouble. JYH HSU(JEC) (or Dongguan Zhixu Electronics) not only has full models of ceramic capacitors with guaranteed quality, but also offers worry-free after-sales. JEC factories are ISO 9000 and ISO 14000 certified. Welcome to contact us: https://www.jeccapacitor.com

 Varistor in Parallel Circuits

The voltage dependant resistor or varistor is a resistive component which has the nonlinear volt-ampere characteristic. It can be used to clamp the voltage when the voltage of some circuits is too large and the electrical device cannot bear it, so as to protect the device. The abbreviation of the voltage dependant resistor is VDR. It can be used in parallel with the device to be protected in the circuit.

As we know that the varistor has the function of lightning protection. So what is the working principle of the varistor in the parallel circuit?

The varistor is used in parallel with the electrical equipment or components to be protected. When lightning overvoltage or transient overvoltage occurs in the circuit, the varistor and the protected equipment and components bear the overvoltage at the same time. Due to the fast response speed of the varistor, it quickly presents excellent nonlinear conductive characteristics in nanoseconds. At this time, the voltage at both ends of the varistor drops rapidly, which is much smaller than the overvoltage, so that the equipment and components are protected from the impact of overvoltage.

Varistors are well known and used because of their superior performance. When purchasing varistors, you should choose regular manufacturers to avoid troubles.

JYH HSU(JEC) Electronics Ltd (or Dongguan Zhixu Electronic Co., Ltd.) is an electronic components manufacturer. Our factories are ISO 9000 and ISO 14000 certified. If you have technical questions or need samples, please contact us: https://www.jeccapacitor.com/