Capacitance is an electronic component that is widely used in mobile phone chargers and power adapters. It is mainly used as a filter to resist interference and is one of the essential components of the charger. Rechargeable head network consulting industry engineers learned that the aluminum electrolytic capacitors in mobile phone chargers are divided into high-voltage aluminum electrolytics and low-voltage electrolytic capacitors. The primary side uses high-voltage aluminum electrolytic capacitors to smooth the ripple DC output from the rectifier bridge. , to reduce the pulsating component. The high-frequency aluminum electrolytic capacitors used in general switching power supplies can simultaneously process rectified filtering and filtering during switching power supply operation.
The specifications of the primary side electrolytic capacitor are generally 400V or 450V, and the single capacitor capacity is between tens and hundreds of microfarads. The primary capacitor size of the charger is determined by the output power. The greater the power, the greater the capacitance. USB PD chargers that generally support high power output will use multiple capacitors in parallel to increase the capacity and meet the design requirements.
The secondary side generally uses solid capacitors for filtering, smoothing the half-wave rectified DC current, reducing the ripple, and providing a stable output. Early chargers used electrolytic capacitor filtering. With the increase of power density, the output power of the charger increases, and the output ripple is more demanding. Traditional electrolytic capacitors can no longer meet the needs of high-end chargers. Take the common Huawei FCP charger that supports 9V output, the output side uses two solid capacitors with a green voltage of 12V, and the secondary capacitor capacity of the charger will be in hundreds of units depending on the output power. Thousands of