Summarize the parameters to pay attention to when purchasing film capacitors

To purchase a good capacitor, in addition to the quality assurance that the capacitor must be certified and produced by a regular manufacturer, it is also important to note that the capacitor cannot be purchased blindly. Choosing inappropriate capacitors will affect the circuit and cause unnecessary losses. The following editor will tell you the parameters to pay attention to when choosing film capacitors to prevent you from restricting the purchase of the wrong capacitors.

1. Rated voltage

Rated voltage refers to the voltage value applied to both ends of the capacitor that the film capacitor can work normally, stably and reliably within a certain period of time in the circuit. The rated voltage is not only related to the dielectric and device structure used by the capacitor, but also related to the environment in which the capacitor is located. When the frequency and temperature rise, the rated voltage will drop. Therefore, you should pay attention to the rated voltage of the capacitor when purchasing a film capacitor. If the temperature rises sharply, then the voltage applied to both ends of the film capacitor should be reduced accordingly. But fortunately, when choosing a film capacitor, you should choose a capacitor whose rated voltage is slightly higher than the actual demand to ensure the normal, stable and reliable use of the capacitor.

2. Electric capacity

The capacitance is very important. It is related to whether the capacitor can meet the needs of the circuit, and it is to ensure that the circuit can reach the goal determined during the design. The capacitance of a capacitor refers to the storage capacity of the capacitor for charge. When purchasing, you should choose the capacitance required by the circuit. You can choose a larger one, but not too much.

3. Temperature coefficient

The temperature coefficient refers to the ambient temperature range in which the capacitor can work stably in the circuit. Generally, the temperature coefficient range of the film capacitor is between -65°C and +250°C. The capacitor with the appropriate temperature coefficient can be selected according to the temperature of the working environment.

4. Loss

Loss refers to the energy that the capacitor loses due to heat dissipation per unit time in the circuit. The heat dissipated by the loss of the capacitor will increase the temperature of the capacitor itself, and part of the heat will be dissipated to the surrounding environment. When purchasing, you should try to choose a thin film capacitor with low loss, so that the capacitor can store more charge in the capacitor instead of converting electrical energy into heat for useless work.