The rated voltage of 12v4a and 12v5a power adapters is 12V. The main difference is that the rated current of the former is 4A and the rated current of the latter is 5A.
Because the power is equal to the voltage multiplied by the current, the rated output power of 12v5a is higher than that of 12v4a. If 12v4a is used on the original 12v5a appliance, the current and power in actual use exceed the rated value of 12v4a power adapter. If it is overloaded for a long time, the power adapter will burn out. Therefore, 12v4a power adapter should not replace 12v5a.
The voltage of the power adapter is generally stable at 12V ± 0.6V when the output current does not exceed its rated specification value, such as 5A. If the current is greater than the rated specification value, the output voltage may be too low, or even protected. If the power adapter is not protected, it will generate serious heat and shorten its service life.
Their output current in actual work does not necessarily reach its maximum current. Sometimes, it is possible to output only 1A or even less than 0A during operation. However, the maximum output current must not be exceeded during use.
When using some electrical appliances, you should pay attention to the voltage and current required by the electrical appliances. The voltage must be consistent, and the current only needs to be greater than the demand of the electrical appliances.
