How the power adapter works?
The working principle of the power adapter is to convert the unstable power supply into constant voltage DC electricity needed by the laptop computer through the principle of switching power supply, to power and charge the laptop computer. This conversion circuit, there must be a protection circuit.
The power adapter can make use of the principle of switching power supply, the unstable power supply through the conversion circuit into the constant voltage direct current required by electrical appliances, to power and charge electrical appliances. This conversion circuit, there must be a protection circuit (overcurrent protection circuit, overvoltage protection circuit, short circuit protection circuit, etc.), to prevent accidents, protect the electrical appliances will not burn.
The switching power supply and adapter are switching power supply, which are composed of high frequency switching tube and its control circuit. Adapter power supply is a voltage regulator switching power supply, switching power charger is with floating charging function, voltage is smaller and larger with the current, to the end is only voltage and no current.
The working principle of the power adapter is like this, in fact, the power adapter is a high precision, high efficiency switching voltage regulator power supply, its role is to convert 220V AC mains into low voltage direct current, to provide stable power for the normal work of electronic equipment.
Power adapter maintenance steps and methods.
First of all, we have to check what went wrong, if it is line fault: including power line damage, no power, contact port oxidation contact is poor, etc. Focus on checking whether the input line and output line are energized. If the circuit is faulty, replace the power cable.
If the safety is burned out or blown up, mainly check the rectifier bridge, each diode, switch tube and 300 volts on the large filter capacitor and other parts. Lead to safety burning, black, may also be the anti-jamming circuit caused by problems. In particular, it should be noted that the breakdown of the switch tube leads to ignition, which usually burns out the power control chip and the current detection resistor. Thermistors can also easily be burned out along with the safety.
If it is a component problem, because the current power adapter has a lot of patch components, once the component problems, it is more difficult to repair. The power of the power adapter is also increasing day by day, so the test of electronic components is more and more big, if the quality of the electronic components used by the power adapter is not up to standard, PCB wiring is improper, it is likely to increase the probability of failure.
Observe the change of the computer indicator light: if you plug in the power adapter, you can see the charging indicator light on and off, there is a time has not been off, it is the notebook inside the power adapter interface has a problem, generally may be broken inside the line, circuit board aging, welding drop and other reasons. This is called virtual welding phenomenon. This situation is only called professional personnel repair.
