Generally speaking, China power adapters and chargers are not the same thing. The former is a power switch, which is used to provide energy; the latter is used to charge the battery, which will be used for charging in stages according to the battery capacity and charging characteristics.
The main points are as follows:
(1) Power adapter: It is a small portable electronic equipment and power conversion equipment. It consists of shell, transformer, inductor, capacitor, control chip, printed circuit board, etc.
(2) Charger: It is composed of stable power supply (mainly stable power supply, stable working voltage and sufficient current) plus necessary control circuits such as constant current, voltage limiting and time limiting.
(1) Power adapter: from AC input to DC output, indicating power, input and output voltage, current and other indicators.
(2) Charger: It adopts constant current and voltage limiting charging system. The general charging current is about C2, that is, a 2-hour charging rate is used. For example, a 250mAh charge rate for a 500mah battery is about 4 hours.
(1) Power adapter: The correct power adapter requires safety certification. The power adapter with safety certification can protect personal safety and prevent electric shock, fire and other hazards.
(2) Charger: It is normal for the battery to have a slight temperature rise in the later stage of charging, but if the battery is obviously hot, it means that the charger cannot detect that the battery is saturated in time, resulting in overcharging, which is harmful to the battery life.
(1) Power adapter fuse: it is mainly used for overload protection. If the fuse is properly placed in the circuit, the fuse will cut off the current when the current abnormally rises to a certain height and heat, thus protecting the safe operation of the circuit.
(2) Inductance coil (also known as choke coil): it has the effects of choking flow, tuning and frequency selection.
(3) Rectifier bridge: convert alternating current into direct current.
(4) Varistor: it is mainly used for voltage clamping when the circuit is subjected to overvoltage, absorbing excess current to protect sensitive devices.
(5) PWMIC (integrated circuit): with a certain technology, the transistors, resistors, capacitors, inductors and other components and wiring required in a circuit are interconnected and fabricated on a small or several small semiconductor wafers or dielectric base chip, and then encapsulated in a tube case to become a miniature structure with the required circuit functions; all components have been structurally formed as a whole, making electronic components take a big step forward towards the direction of miniaturization, low power consumption, intelligence and high reliability.
(6) Switching transformer: the DC input voltage is regarded as a series of DC pulse voltage, that is, unipolar pulse voltage, through the function of controlling the switch on and off, which directly supplies power to the switching transformer.
(7) Electrolytic capacitors: electrolytic capacitors are named because they use electrolytes as electrodes (negative electrodes). One end of the electrolytic capacitor is positive and the other end is negative, which cannot be reversed. The positive terminal is connected to the positive terminal of the rectifier output circuit, and the negative terminal is connected to the negative terminal of the circuit. In all circuits that need to convert alternating current into direct current, setting the filter capacitor will make the working performance of the electronic circuit more stable, and also reduce the interference of the alternating ripple on the electronic circuit.
(8) Power adapter high-power switch tube: it is one of the core components in the switching power supply. The switching power supply can work "one on and one off", and the switch tube is indispensable.