AC Adapters/ Charging Adapters
Today we will be learning about AC Adapters/ Charging Adapters.
AC Adapters:
An AC adapter is a type of external power supply. AC adapters are used with electrical devices that require power but do not contain internal components to derive the required voltage and power from mains power. The internal circuitry of an external power supply is very similar to the design that would be used for a built-in or internal supply.
Most AC/DC Adapters are linear power supplies,containing a transformer to convert the mains electricity voltage to a lower voltage, a rectifier to convert it to pulsating DC, and a filter to smooth the pulsating waveform to DC, with residual ripple variations small enough to leave the powered device unaffected.
A linear circuit must be designed for a specific, narrow range of input voltages (e.g., 220–240VAC) and must use a transformer appropriate for the frequency (usually 50 or 60 Hz), but a switched-mode supply can work efficiently over a very wide range of voltages and frequencies; a single 100–240VAC unit will handle almost any mains supply in the world.
Advantages:
External AC adapters are widely used to power small or portable electronic devices. The advantages include:
- Safety — Much of this style of equipment uses only voltages low enough not to be a safety hazard internally, although the power supply must out of necessity use dangerous mains voltage.
- Heat reduction — Heat reduces reliability and longevity of electronic components, and can cause sensitive circuits to become inaccurate or malfunction. A separate power supply removes a source of heat from the apparatus.
- Configuration versatility — Externally powered electronic products can be used with different power sources as needed (e.g. 120VAC, 240VAC, 12VDC, or external battery pack), for convenient use in the field, or when traveling.
Problems:
While useful for many purposes, some external AC adapters have attracted criticism. Problems with this type of power supply include, but are not limited to:
- Size — Power supplies which plug into the mains directly without using a plug on a cable (true wall warts) are bulkier than bare plugs; sometimes they are too large to plug into power sockets with restricted space, or into adjacent sockets on power strips (due to the fact that they can block other plugs also).
- Inefficiency — Some idling power is wasted as the power supply is left running when the equipment power switch is off or the equipment is disconnected from the power supply. In recent years it has become common for equipment with internal supplies to share this problem due to the use of a "soft" power switch.
- Compatibility problems — There is no standardization of connectors; the same connector is often used for different voltages, and for both DC supplies and AC-to-AC transformers. Incompatible voltage or polarity may be present on physically interchangeable connectors. This easily leads to using the wrong power supply, which can destroy equipment.
USB Adapters:
The USB connector (and voltage) has emerged as a standard in low-power AC adapters for many portable devices. In addition to serial digital data exchange, the USB standard also provides 5V DC power, up to 500 mA (900 mA over USB 3.0). Plug-in adapters equipped with USB receptacles are widely available to convert 120 V AC or 240 V AC power or 12 V DC automotive power to 5 V DC USB power (see photo at right).
Qualcomm Quick Charge:
Quick Charge allows for high levels of current to flow to the battery, in an attempt to maximise its charging efficiency. The latest Quick Charge products also tend to charge their batteries at higher voltages, allowing for a higher rate of power transfer through commonly found cables.
However, both the phone and the charger must be compatible with the same charging voltages and currents. Your phone may support charging at 9V/2A, but if you only have a 1A charger then the process will take longer. Likewise, plugging a 2A charger into a phone that can only accept 0.7A won’t make it charge any faster.
Quick Charge 3.0:
Qualcomm's latest line of SoCs have a new charging feature, dubbed Quick Charge 3.0. The new standard, which will ship on the Snapdragon 820, 620, 618, 617, and 430 next year, promises to take a phone battery from 0 to 80 percent in about 35 minutes. Qualcomm says the new charging standard will "improve fast charging up to 27 percent or reduce power dissipation by up to 45 percent when compared to Quick Charge 2.0." provided vendors use Qualcomm's "advanced parallel charging configurations."
The new standard uses an algorithm called "Intelligent Negotiation for Optimum Voltage (INOV)" which lets the device continually request a power level from the charger, from 3.6V to 20V, in 200mV increments. Quick Charge 2.0 only offered four charging voltages, but 3.0 offers 82 different voltage "sizes," which Qualcomm says results in "minimized losses, increased efficiency, and improved thermal performance."
Quick Charge 3.0 is backward compatible with versions 1.0 and 2.0 and is connector-independent. You'll need a new phone and a new charger to take advantage of the higher speeds.
For smartphones, the actual maximum amount of power available has not really changed from Quick Charge 2.0’s 18W maximum. Newer 9V models will still take the same 18W peak power as before, although lower voltage batteries may receive a power boost, allowing them to charge up a little faster than before. But this all depends on the exact hardware.
MTK Pump Express:
It has a charging output of 9V but it also provides for the 7V ones. It has been released for some charging technology platforms like the MT6595 or the MT6732.
The model HF-QC-084 charger will be carrying the tech and it offers an input of 100-240V and an output charging voltage of 5V 1.67A(8035W), 7V 1.67A(11.69W), and 9V 1067A(15.3W). It will charge a smartphone from 0% to 75% in just 30 minutes if yo have a 2060 mobile battery, which makes it one of the fastest MTK phone chargers. And even if you charge it for just five minutes, it will give you a call time of up to 2 hours.
Aside from fast charging, the technology also offers port overload protection, system temperature protection, battery voltage protection, battery fuse protection and other features that will ensure comprehensive safety for your charger and the devices it powers. Let's see which tech companies will take up MTK Pump Express Plus in their offer of really fast charging technology.
AC Adapter Schematic
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