MANUAL CHARGING CONTROL

The Wind up battery is the endless independent source of power. It is the only tool you will need to charge your mobile phone batteries, notebook batteries, GPS or any other modern gadget which is in this information-packed world essential life companion. The use of wind up battery charger is easy and being that it is totally portable and independent power supply, it is a valuable part of accessory of every trekker’s, backpacker’s, traveler’s adventures journey. It is also an essential back up power supply for any critical emergency events when there is no power supply available nearby.

How does it work?

The wind up battery mechanism uses internal generator, which is usually hand-powered by spinning the handle on the device. The hand motion, in which AC alternator is driven by a crank converts human mechanical energy and generates the electrical power, by spinning magnets past a coil of wire, which is stored in battery. To charge the device, utilizing the wind up mechanism the hand crank needs to be pulled out of the folded position, and spun in clockwise/counterclockwise direction. After some time of cranking, when the device is charged the handle is folded into position and the device is available to use.

There are also foot powered wind up battery devices, which generate power and self charge by human energy through step action. These are able to jump-start a boat or automobile battery, and power a wide array of instruments and accessories and present a valuable and versatile tool for power supply.

The Devices using wind up mechanism

There are several devices on market which utilize the wind up mechanism. It can be used as a wind up battery charger, wind up flashlight, wind up radio, wind up clock, mp3 player, or a larger electricity supply unit. Usually there are hand cranks folded into the devices, which can be pulled out when needed. The wind up devices are a great way to promote environmentally clean green energy source as the power is derived through windup mechanism which efficiently harvests the human energy and converts it to electricity.

If you are an environmentally conscious consumer who likes to travel and have a power charger available for his electric devices and an emergency power supply then the wind up battery is the device to look for.

INDUCTIVE CHARGING

In the future all electronic devices will be wirelessly powered. Small, battery-powered gadgets make powerful computing portable.

The battery charger should be capable of charging the most common battery types found in portable  devices today.  In addition, the charging  should be  controlled from the base station and a bidirectional communication system between  the pickups  and base  station  should be developed.

Inductive Power Systems:

Inductive Power Transfer (IPT)  refers to the concept of transferring electrical power between two isolated circuits across an air gap.  While based on the work and concepts developed by pioneers such as  Faraday and Ampere, it  is  only recently that IPT has been developed into working systems.

Essentially, an IPT system can be divided into two parts;

• Primary and
• Secondary.

The primary side of the system is made up of a resonant power supply and a coil. This power supply produces a high frequency sinusoidal current in the coil.  The secondary side (or ‘pickup’) has a smaller coil, and a converter to produce a DC voltage.

Working of Inductive Power Transfer:

In this system communications signals are encoded onto the waveform that provides power to the air gap. Communication from the primary side to the secondary is implemented by switching the power signal at the output of the resonant converter between its normal level  and a lower level which is detectable by the pickup but still provides enough power to control the pickup microcontroller. This process is called Amplitude Shift Keying (ASK). This is achieved by varying the output voltage of the buck converter which provides an input DC voltage to the resonant converter.

Communication from the secondary to the primary is achieved by a process called Load Shift Keying (LSK).  This involves varying the loading on the pickup.   Any load on the pickup will reflect a voltage on the primary circuit proportional to the load.  Therefore a variation in the load on the pickup can be detected by the charging station.

The communications system must provide two discrete levels of voltage reflected onto the primary side,  to represent the on and off states for digital communications. The difference must be easily detected on the primary side to provide a robust communications channel. Signals are decoded by simple filters and comparators which feed a  digital signal to the microcontrollers.

Advantages:

IPT has a number of advantages over other power transfer methods  – it is unaffected by dirt, dust, water, or chemicals.  In situations such as coal mining IPT prevents sparks and other hazards.  As the coupling is magnetic, there is no risk of electrocution even when used in high power systems.  This makes IPT very suitable for  transport  systems where vehicles follow a fixed track,  such as  in factory materials handling.