USB interface chargers should not be mixed at will
2022-11-18 Views:42
Most of the output interfaces of cell phone chargers (power adapters) are USB type, different brands and models of cell phone chargers, although the output voltage is 5V, while the output current is different, these different output current chargers can be used interchangeably?
To clarify this issue, we must first understand how the current is controlled when charging cell phones. After multiple inquiries on the Internet and consultation with cell phone manufacturers and power adapter manufacturers, the conclusion is that it is best not to mix at will.
1. the amount of current when charging the phone, the charging process on the display screen and the termination of the charge when full, is controlled by the phone's internal circuitry.
2. the output current marked on the nameplate of the power adapter is a reference value, and it is best to use it in a state equal to or less than this current value.
3. desktop power adapter is not a constant current source based on the calibrated output current.
Power adapter manufacturers in determining the output current of a product, in the circuit design and component selection, should make the circuit and components and determine the output current to adapt, match, for example, the size of the high-frequency transformer core specifications, winding wire diameter thickness, rectification mode and the choice of component specifications, the size of the capacity of the filter capacitor, are based on the calibrated output current value after meticulous selection Therefore, it is possible to generate a power adapter with an output voltage of 5V and a marked output current.
As a power supply, no matter how perfect the design is, it always has to have internal resistance, just like the distribution transformers used in factories and rural areas, its rated voltage is lOkV/0.4kV, that is, its secondary no-load rated voltage is 400V, while the rated voltage of motors and other electrical equipment is 380V, here is the use of the transformer's power internal resistance and transmission lines may appear on the Voltage drop, etc., so that the voltage between the power supply and the load can be basically matched.
Based on the above analysis, when the calibrated output current of the charger (power adapter) is greater than the current required to charge the phone, the charger can easily complete charging under the control of the power management module inside the phone until the battery is full and the power management module issues a charging termination command.
When the calibrated output current of the charger (power adapter) is less than the current required for charging the phone, the control command issued by the internal power management module of the phone and the internal resistance of the charger jointly determine that if it is less than the optimal charging current but more than the calibrated output current of the charger, the output voltage of the charger will be slightly reduced at this time and the heat generation will be slightly increased, however, the charging of the phone can usually be completed within a few hours, which is not yet However, the phone charging can usually be completed within a few hours, not to cause damage to the charger, but the charging time may be extended.
Therefore, BON believes that the best solution is to use the original charger to charge the phone, or choose a power adapter with a calibrated output current equal to or greater than the current value required for charging; it is best not to use a charger with a calibrated output current less than the phone's charging current to charge the phone. For more information about power adapter, please pay attention to Shenzhen BON Electronics Co.,LTD.