Charge your phone
Most mobile phone chargers are not really chargers, only adapters that provide a power source for the charging circuitry which is almost always contained within the mobile phone. They are notably diverse, having a wide variety of DC connector-styles and voltages, most of which are not compatible with other manufacturers' phones or even different models of phones from a single manufacturer.
Users of publicly accessible charging kiosks must be able to cross-reference connectors with device brands/models and individual charge parameters and thus ensure delivery of the correct charge for their mobile device. A database-driven system is one solution, and is being incorporated into some designs of charging kiosks.
Mobile phones can usually accept relatively wide range of voltages, as long as it is sufficiently above the phone battery's voltage. However, if the voltage is too high, it can damage the phone. Mostly, the voltage is 5 volts or slightly higher, but it can sometimes vary up to 12 volts when the power source is not loaded.
There are also human-powered chargers sold on the market, which typically consists of a dynamo powered by a hand crank and extension cords. There are also solar chargers.
China and other countries are making a national standard on mobile phone chargers using the USB standard. Starting in 2010, Apple, Nokia, Motorola, Samsung and RIM will begin making handsets with a standard phone charger based on the micro-USB connector. On October 22, 2009 the International Telecommunication Union announced a standard for a universal charger for mobile handsets (Micro-USB).
Mobile phones generally obtain power from rechargeable batteries. There are a variety of ways used to charge cell phones, including USB, portable batteries, mains power (using an AC adapter), cigarette lighters (using an adapter), or a dynamo. In 2009, wireless charging became a reality, and the first wireless charger was released for consumer use.
Standardization of Micro-USB connector for charging
Starting from 2010, many mobile phone manufacturers have agreed to use the Micro-USB connector for charging their phones. The mobile phone manufacturers who have agreed to this standard include:
- LG [[1]]
- Motorola [[2]]
- Nokia [[3]]
- Research In Motion [[4]]
- Samsung [[5]]
- Sony Ericsson [[6]]
On 17 February 2009, the GSM Association announced that they had agreed on a standard charger for mobile phones. The standard connector to be adopted by 17 manufacturers in the Open Mobile Terminal Platform including Nokia, Motorola and Samsung is to be the micro-USB connector (several media reports erroneously reported this as the mini-USB). The new chargers will be much more efficient than existing chargers. Having a standard charger for all phones, means that manufacturers will no longer have to supply a charger with every new phone.
In addition, on 22 October 2009 the International Telecommunication Union (ITU) announced that it had embraced micro-USB as the Universal Charger Solution its "energy-efficient one-charger-fits-all new mobile phone solution", and added: "Based on the Micro-USB interface, UCS chargers will also include a 4-star or higher efficiency rating — up to three times more energy-efficient than an unrated charger."
Charger efficiency
The majority of energy lost in a mobile phone charger is in its no load condition, when the mobile phone is not connected but the charger has been left plugged in and using power. To combat this in November 2008 the top five mobile phone manufacturers Nokia, Samsung, LG Electronics, Sony Ericsson and Motorola set up a star rating system to rate the efficiency of their chargers in the no-load condition. Starting at zero stars for >0.5 W and going up to the top five star rating for <0.03 W (30 mW) no load power.
A number of semiconductor companies offering flyback controllers, such as Power Integrations and CamSemi, now claim that the five star standard can be achieved with use of their product.
Battery
Formerly, the most common form of mobile phone batteries were nickel metal-hydride, as they have a low size and weight. lithium ion batteries are sometimes used, as they are lighter and do not have the voltage depression that nickel metal-hydride batteries do. Many mobile phone manufacturers have now switched to using lithium-polymer batteries as opposed to the older Lithium-Ion, the main advantages of this being even lower weight and the possibility to make the battery a shape other than strict cuboid. Mobile phone manufacturers have been experimenting with alternative power sources, including solar cells and Coca Cola.
- Your mobile phone charger is more powerful than it looks.
- Much of of the energy used by the phone chargers in this country is wasted.
- They’re only doing their job – i.e. charging phones – for a small part of the time.
- The new style transistor and diode based chargers are better than the heavy old school transformer ones- you might have noticed they have got a lot lighter.
