GB2440396A

GB2440396A - Power generation using earth's field

Info

Publication number: GB2440396A
Application number: GB0614765A
Authority: GB
Inventors: Mark Wells
Original assignee: Individual
Current assignee: Individual
Priority date: 2006-07-25
Filing date: 2006-07-25
Publication date: 2008-01-30
Anticipated expiration: 2026-07-25
Also published as: GB0614765D0; GB2440396B

Abstract

The apparatus comprises a blocking/shielding means for changing the extent to which the earth's magnetic filed is experienced at a region. A power generator at the region generates power in response to the changing magnetic field at the region. In some embodiments, the blocking/shielding means is arranged to reverse the magnetic filed experienced at the region. Additional embodiments not involving the earth's magnetic field are disclosed in respect of charging laptop computers via a capacitive load and include piezo-electric keys, piezo-electric layer under keyboard, key drive magnet and coil or key driven pneumatic system. The piezo-electric system can also act as pressure transducers to monitor computer access or manners of use e.g. warning of repetitive strain injury.

Description

GENERATION OF POWER

This application relates to the generation and/or harnessing of power, in particular for use in powering or re-charging devices for wireless use. More particularly, this application relates to provision of wireless power for use with devices, particularly computers, in environments where it is either impractical or inconvenient to provide a wired connection. The main focus of this technology will initially be for laptop computers.

There are a number of reasons why a wireless source of power is desirable, particularly for the laptop computer.

Over the last decade or so the use of laptop computers has become increasingly popular.

Increasingly the wires that tie a user to the desk have been removed. This started with the infrared/ultra sonic mouse, then the keyboard, then wireless versions of both. The advent of the wireless network has given us instant connection to the worldwide web, as well as local connections for printing or data sharing without the necessity of cable connections between devices.

Not only has this wire-free lifestyle greatly affected the office environment, it has also become very popular in home computing, particularly alongside the increased accessibility of broadband services. The same technology now means that many airports and cafes have wireless access areas.

This portability provides almost complete freedom for computing and access to information, the work environment and gaming areas. Provision of power, however, remains a significant problem.

The pursuit of long battery life has brought forward many developments and brought down the power consumption and the charge cycle. However, the life of a fully charged laptop computer is still relatively modest and highly variable. Like the mobile telephone, battery life might be quoted at many hours duration, but that all changes if you actually want to use the technology -when the power is consumed more rapidly.

The last remaining barrier to true portability is thus the lack of a wire-free method of powering a device. There is currently no viable solution to this problem.

Currently the only technique for providing a wire-free power source is the wind-up system such as that used for radios or torches. There are developments currently in place or under consideration to use hydrogen fuel cells, but these are not yet a marketable option, and in any case have significant practical drawbacks.

Clockwork power generation is the only current technique for providing wireless power that is truly self contained and does not require refilling or recharging. However, the amount of power required for the practical application of a device such as a laptop computer would require frequent rewinding, which would be inconvenient for the user.

There are reports of fuel cells that will power a typical laptop for between 14 hours and two days. However, an inherent problem with fuel cells is that they utilise highly flammable fuels.

It is unlikely, for example, that a fuel cell-powered device would be allowed on board an aeroplane, and may receive significant opposition in places like hospitals. In any event, this is a system that still requires a form of recharge, and does therefore not satisfy the need for a fully independent means of powering a portable device.

The subject matter of the present application seeks to address one or more of the above-described problems.

Power can either be generated locally to the device or transmitted to it from a remote location. Two systems are described below -one remote, one local.

Remote Power Transmission There are a number of radiant forms of power that can be harnessed and converted to a usable electric current. One of these is the solar cell, but the level of light radiation that would be needed to power the average laptop computer could also result in severe sunburn for the operator. In fact, this is an important consideration with any form of transmitted power (for example laser, Infrared, electromagnetic induction and various others) as they all have the opportunity to adversely affect the user.

Advantageously, a system may pass power from a remote point to a device such as a laptop computer without damaging the user -or anyone else that shares the environment. This presents a fundamental difficulty; any energy that is imposed on an environment has the potential to cause damage to people working in that environment. The actual levels of risk are not always fully understood, but people often refuse to live under pylons and thus even where risk levels are unknown people tend to be unwilling to position themselves in the path of "airborne" energy.

The Earth has a magnetic field. It is present everywhere that matters and it can be switched on and off (or at least it can be blocked or shielded from certain areas by either mechanical or electrical/electronic means). The intermittent switching of a barrier device to the Earth's magnetic field creates a changing electromagnetic environment which in turn can create current flow in an electrical circuit or physical movement of a magnetised vane (akin to a compass needle attached to a micro-generator). Either of these can be harnessed to supply a charging current to a battery of a device such as a laptop.

It is important to note that the above-proposed solution does not increase the level of ambient energy in the environment.

There are a number of implementations available that feed off the changing magnetic field described above. There are also variations to the technique described that could have beneficial effect. For example: * Rather than simply removing or masking the natural magnetic field, the field could be reversed, creating approximately twice the amount of field variation and therefore transmitting twice the amount of power, whilst still keeping the electro-magnetic field strength within normal ambient levels.

* It would also be possible to use the power transferred in this way physically to move a vane against a piezo device, (thereby potentially tying the two methods together in one environment).

Local Power Generation Alternatively, the user may generate the power. Whilst the user generates power for a wind-up radio or wind-up torch these require the deliberate action of choosing to wind up a clockwork or inertia-based device in order to set in motion the generation of electrical power.

The system described here does not rely on any such de'iberate action but uses the actions that the user is making anyway.

The user's movements in making keystrokes may be harnessed to generate power that will maintain the charge level in the device's battery. There are a number of ways of achieving this, but a preferred route is to utilise the piezo-electric effect. The physical action of pressing a key on the keyboard generates power through a piezo-electric device. Again, this can be harnessed in a number of ways, for example, the piezo may be used to charge a capacitive load which will in turn charge a battery. When the charge on the capacitor reaches a certain level it discharges to the battery; charging it in the process.

The capacitive load can be paralleled across a number of or all of the keys. A certain amount of screening for RFI may be required. Initial calculations suggest that there is a balance point that may be difficult to achieve where the power generated by the keystroke exceeds the power utilized by the action it creates, but even in this case it is likely that the battery duration would be extended beyond twelve hours. In some embodiments a "dummy" or "charge" key could be included. This could be oscillated to give a little extra boost, but is considered unnecessary in most applications.

Even in the case where the recharge is adequate only to extend the battery cycle the performance is equivalent to the fuel cell concepts currently being developed, but, advantageously without the need for noxious substances. The device (for example, a laptop computer) simply needs to be recharged in the conventional manner when not in use -there is no necessity to fill it with hydrogen.

Although the piezo effect is the preferred choice, there may be environments where the generation of the electrical interference that it could cause would be best avoided. In such cases there are alternative methods that still allow the harnessing of the human power: * Each key could drive a tiny air compressing sack with a one way valve, creating an air pressure on a manifold that could drive a micro rotary generator.

* Each key could drive a magnetic element in and out of a coil, generating small current.

* The whole keyboard could be mounted on a piezo layer rather than each key or groups of keys having their own piezo.

Advantageously, as well as generating power the piezo system can act as a pressure transducer, providing information on the pressure that is being used on a computer keyboard by an operator. In particular it can provide that information based on the key being used and/or the application being used at the time. This has the potential to detect incorrect or inappropriate use that could in turn be used to identify training requirements or to provide information on the operator that could assist in the prevention of work related illnesses such as repetitive strain injury.

It could also provide a characterisation of the user based on the relative pressure pattern used on different keys, allowing the computer to know who is using it -or at least to validate the user name against the user's keyboard use. This could be lased on a simple algorithm, for example just looking at how the password is entered, or it could apply to the general usage of the system.

The skilled person will appreciate that further modifications may be made as appropriate.

The above systems, and modifications thereof, may be interchanged or combined as appropriate.

In summary, the subject matter of the present application provides: 1 The distinction between invading the ambient to transmit power and utilising the reduction of the ambient to do this, thereby reducing and preferably removing any possibility of raised energy levels, of whatever type, causing harm or distress to the user or third parties; 2 The harnessing of this system by, for example, electrical or mechanical methods; 3 The utilisation of the piezo-electric effect to generate power that can be harnessed to deliver charge to a rechargeable device; 4 The specific application of this system to, for example, a computer keyboard or gaming device; The possibility of harnessing both of these systems in a single environment to deliver higher and therefore more practicable power levels; 6 An increase in battery duration to a workable period; 7 The possibility of achieving enough power to exceed the consumption rates (in particular with the piezo system); 8 Wider applications relevant to training, Healthy Working and Security.

Other uses and advantages of the subject matter described herein will be apparent to the skilled person.

Claims

CLAIMS: 1. An apparatus for providing power, comprising: barrier means

for blocking or shielding the earth's magnetic field, wherein the barrier means is operable to intermittently block or shield the earth's magnetic field; and power generation means operable to generate power in response to a changing

magnetic field resulting from the barrier means.

2. An apparatus according to claim 1, wherein the power generation means comprises an electrical circuit, and wherein the barrier means is operable to cause current flow in the electrical circuit.

3. An apparatus according to claim 1, wherein the power generation means comprises a magnetised vane, and wherein the barrier means is operable to cause movement of the vane.

4. An apparatus according to any preceding claim, wherein the barrier means is operable to reverse the magnetic field experienced by the power generation means.

5. An apparatus according to any preceding claim, operable to transmit or transfer power to a local wireless device 6. A wireless device comprising an apparatus according to any one of claims I to 5.

7. A laptop computer comprising an apparatus according to any one of claims 1 to 5.

8. A method of generating power, comprising the steps of: intermittently blocking or shielding the earth's magnetic field from a region, in order to change the magnetic filed at the region; and using a power generation means at the region, to generate power in response to the

changing magnetic field.

9. A method according to claim 8, wherein the step of blocking or shielding comprises

reversing the magnetic field at the region.

10. An apparatus for generating power as herein described.

II. A method of generating power as herein described.