Common problem
What is high frequency electrolytic capacitors?
When we manufacture and purchase electrolytic capacitors in the market, they are mainly divided into ordinary capacitors and high frequency capacitors. So what exactly is the difference between the two?
Electrolytic capacitor has aluminum case outside, electrolyte inside and two positive and negative electrodes, which is the main function of electrolytic capacitor, i.e. to reduce ripple and stabilize current, and it is widely used in switching power supply, LED lights, household appliances and other products. The working process of electrolytic capacitor can be understood as the process of charging and discharging, so for theoretically speaking, it does not consume energy, but in the actual application, because electrolytic capacitors will be hot, so they will produce the consumption of capacity, which is due to the existence of internal resistance.
2, electrolytic capacitor classification
Electrolytic capacitors are now divided into two categories, one is aluminum electrolytic capacitors, the other is tantalum electrolytic capacitors, the main difference between these two is that the anode material is different, both are electrolytic capacitors more commonly used in circuits, as electrolytic capacitors, its capacity is generally above 1μF, but the capacity of 1μF capacitors are not necessarily electrolytic capacitors, there are also other capacitors, such as monolithic capacitors, polyester capacitors, etc.
3, Ordinary electrolytic capacitors
Aluminum electrolytic capacitors are the most demanded capacitors in display applications. Aluminum electrolytic capacitors are relatively cheap, high capacity and cost effective, but they are prone to leakage and suitable for filtering. Due to the large internal resistance of aluminum electrolytic capacitors, resonance will occur when the frequency is higher than a certain condition, which is capacitive until then and inductive beyond this frequency. At this time, we can ignore the parasitic effect of the capacitor on the circuit.
4, high frequency electrolytic capacitors
High frequency electrolytic capacitor is relative to common electrolytic capacitor, as the name implies, high frequency capacitor is used in high frequency applications, and the capacity of high frequency capacitor cannot be as large as common electrolytic capacitor, so it is suitable for circuits with high frequency, such as filtering of switching power supply. The output filtering electrolytic capacitors in switching power supply, whose output voltage frequency is up to tens of kHz, or even tens of MHz, for ordinary electrolytic capacitors, which have long been inductive at this frequency, but high frequency capacitors can play a good filtering role.
