What is a power adapter?
What is a power adapter? The power adapter is also called an external power supply and is generally used to convert the power and voltage of portable electronic devices. It is usually used in small electronic products such as mobile phones, LCD monitors and notebook computers. Its function is to convert the high voltage of 220 volts at home into a stable low voltage of 5 to 20 volts that electronic products can work, so that they can work normally.
There are two main types of power adapters-switching power supplies and linear power supplies.
1. Switching power supply is a power supply that uses modern electronic technology to control the switching time ratio and maintain a stable output voltage. The switching power supply of the power adapter is generally composed of pulse width modulation (PWM), control IC and MOSFET.
Advantages: The switching power supply has high efficiency, small size and can work in a wide voltage range.
Disadvantages: The switching power supply has a great interference to the power circuit, and it is difficult to eliminate the fault when the fault occurs.
2. The linear power supply converts AC through transformer, rectifier circuit and rectifier filter. In order to achieve high-precision DC voltage, the power adapter must adjust the output voltage through a voltage feedback circuit.
Advantages: The linear power supply technology is mature, the circuit is simple, and the switching power supply has no interference and noise.
Disadvantage: The voltage feedback circuit is always online. Due to the use of an inductive transformer, the regulator consumes a lot of power. It has low conversion efficiency and heavy equipment weight.
If the power adapter is used for a long time, many problems will inevitably occur. For example, the line is prone to failure and voltage instability. So what should be done when there is a failure?
1. First of all, we can judge the situation according to the indicator light. You can see the indicator light of the power adapter. If the indicator light is on, it is generally considered that there is no problem from the power supply to the adapter. It must be ensured that the indicator light itself is not broken.
2. Try to avoid breaking the internal cables to form an open circuit for the power cord. If the power adapter does not supply power, you can plug in the battery and try. If the machine can start normally, there may be a problem with the power cord or adapter. Then check with a multimeter to find out whether there is a problem with the power cord. Don't try to open the power adapter case in the first place. Because it is really too difficult to open the power adapter shell.
3. If there is a problem with the original adapter, which cannot be repaired or is too late to repair, you can use another adapter to replace it first.
4. I have seen a friend on the Internet mention that the adapter has a problem and burns out the computer motherboard. It is estimated that this situation is rare. If so, it is estimated that the regulator circuit inside the laptop is damaged.
5. Do not damage the shell as much as possible. After the shell is damaged, problems such as enhanced electromagnetic radiation will occur, which will affect the stability of the machine. If the shell is damaged, try to repair it. After opening the shell and shield, it is best to check the solder feet first. If the circuit is intermittent, it is generally due to poor contact.
6. The power adapter manufacturer should check the capacitance, resistance and inductance. If the capacitor has a bulge, it is best to replace it in time to avoid hidden dangers.