Basic knowledge of mobile phone charger
Release date：2014-06-18 09:45 Source：本站 Click：浏览次数：
Mobile phone charger tips
A charger, product quality from three aspects of its working performance, safety requirements and electromagnetic compatibility measure.
1, work performance. Different type battery charging has different requirements, mainly has the charging mode, charging charger parameters current, charging voltage requirements.
(1) charging: the provisions of the charger is in a constant current mode or in constant voltage mode to charge the battery. The lithium ion battery is widely used currently, way of charging charger should adopt the limiting constant voltage mode, namely the first with a current limiting charging to battery limit charging voltage can automatically switch to the constant voltage charging.
(2) the provisions of the charger charging current: the maximum output current. The size of the charge current and battery capacity should be applicable to match the size, generally should not be greater than 1C5A.
(3) the provisions of the charging voltage of the charger: maximum output voltage. Charging voltage depends on the battery limit of voltage; nominal voltage for charging the lithium ion battery 3.6V, the highest output voltage charger requirements for general 4.2V (in fact, mobile phone use lithium-ion batteries are equipped with protection device, so the output voltage of the charger can be slightly higher than the 4.2V, but in order to ensure safety, voltage must not more than 4.5V).
2, safety requirements. As is the popular requirements for the product circuit structure, mechanical structure and electrical performance should meet certain security requirements, regardless of whether the product is in the normal working state or abnormal (such as the output overload or short circuit, the internal component failure or circuit fault etc.) the work of the state, shall not harm to people and property safety. In order to achieve this purpose, safety requirements for battery charger products (such as protection against electric shock performance, insulation performance, temperature and so on) shall meet the specified requirements in the national mandatory standards GB4943-2011.
3, electromagnetic compatibility. The charger products, its electromagnetic compatibility requirements mainly reflects in the aspect of electromagnetic disturbance. Electromagnetic harassment harassment for conduction and radiation disturbance. Because of many advantages of switching power supply, so the charger commonly used switching power supply circuit. But the high frequency switch device in switch power supply is opened and closed, will produce the high frequency harmonic signal. These high frequency signals through the power supply terminal via grid communication or by space radiation, will bring the environment of electromagnetic pollution, the normal work of harassment around electronic equipment, may seriously affect the safe operation of power grid and human health caused by adverse. Therefore, in order to reduce the electromagnetic pollution of the environment, the requirements of electronic products work the power supply terminal (or interface terminal) disturbance voltage and radiated disturbance field should be less than a certain value. For mobile phone battery charger, the disturbance voltage and disturbance field should be consistent with the value B limited national mandatory standards GB9254-2008 requirements.
Two, as consumers, the purchase of the charger products a good quality, suitable for use in the following for reference:
1, the purchase of the charger, should carefully read the instructions for use of products or product marking instructions. In general, there is a product certification mark of the charger is safety guarantee. Therefore, should try to choose the product certification logo products.
2, cell phone chargers are generally has two charging measures, one is the charging belt machine (charger through the electric connector and the phones to charge the battery); another is to charge the battery through the charging seat. Before the choose and buy, should clear their own use battery type and capacity, the nominal voltage, in order to purchase and fit the charger.
3, the current mobile phone use of the battery is almost always only a single electrical cores, the nominal voltage is 3.6V, rated capacity of lithium ion battery 500mAh ~ 1000mAh. Requirements for lithium ion battery core on the charging current and the charging voltage is very high; the charging current is too large or the charging voltage is too high, will cause the electric chemical reaction core internal changes, the internal temperature rise, causing material damage or diaphragm electrode, the electric core explosion. Although, the internal general mobile phone battery is provided with the filling, put too protector, overcurrent protection function. But for the sake of safety, in order to achieve better charging effect, should choose the maximum output voltage is 4.2V ~ 4.5V, the maximum output current is 600mA ~ 700mA charger. Charger product specification shall be marked with the use of the output voltage and output current range, and other technical parameters. Conditional word, when the choose and buy is available with the appropriate measurement to measure charger million file table no-load output voltage and output short-circuit current, judge the actual data are consistent with the standard of technical parameters.