GB2465186A

GB2465186A - Solar powered system

Info

Publication number: GB2465186A
Application number: GB0820465A
Authority: GB
Inventors: Mark Ernest Wilkins; Brian Robert Alfred Wybrow
Original assignee: Individual
Current assignee: Individual
Priority date: 2008-11-10
Filing date: 2008-11-10
Publication date: 2010-05-12
Also published as: GB0820465D0

Abstract

A solar powered system for providing electric power to a variety of electrical appliances wherein charging can be carried out via a variety of different configurations of i) solar panel, ii) charging system, and iii) appliance, and wherein, in the case of an appliance such as a lawnmower, the weight of the operated lawnmower is minimised, thereby reducing the power requirement for any particular combination of electric motor and rechargeable battery. An appliance which utilises rechargeable batteries, e.g. the vacuum cleaner, the food mixer, the electric drill, the strimmer, or hedge trimmer, may be standardised so that one system can be used to charge a range of them. One variant of the solar powered system which is used for powering a lawnmower, has the solar panel mountable on the roof, or the wall, of a shed, or the like, on a specially designed mounting panel which can itself be conveniently mounted and adjusted using a three-axis, equatorial mount, so that the solar cells receive the optimum energy from the sun during the daily rotation of the Earth on its axis and during the yearly rotation of the Earth around the sun.

Description

SOLAR POWERED SYSTEM

This invention relates to a solar powered system for providing electric power to a variety of electrical appliances.

The generation of electricity by means of solar cells is well documented, and it is known that batteries can be charged from such a source of electricity. However, methods for utilising solar power for operating certain types of equipment can be considered limited. Thus, whilst solar powered lawnmowers are known, these utilise solar powered cells which form part of the structure of the lawnmower, and although they would appear to provide sufficient time, between episodes of mowing, for the associated batteries to be fully charged, the incorporation of the solar cells into the structure of the lawnmower, introduces inefficiency in operation. Moreover, apart from influencing the design of the lawnmower itself, this incorporation of the solar cells into the design of the lawnmower, also means that the lawnmower itself is necessarily exposed to the sun during charging. Consequently, the lawnmower generally has to be left outdoors during this charging; thereby rendering it vulnerable to theft, damage and deterioration, under certain circumstances.

In contrast, the present invention keeps the solar cells separate from the appliance, thereby allowing charging to be carried out via a variety of different configurations of i) solar panel, ii) charging system, and iii) appliance. Also, in the case of an appliance such as a lawnmower, the weight of the operated lawnmower is minimised, and this reduces the power requirement for any particular combination of electric motor and rechargeable battery.

Many other electrically powered appliances utilise rechargeable batteries which are traditionally powered from the mains supply, and it is thus suggested that by careful design of any appliance which utilises rechargeable batteries, e.g. the vacuum cleaner, the food mixer, the electric drill, the strimmer, or hedge trimmer, etc., and by careful design of the system of i) solar cells, ii) rechargeable batteries, and iii) associated circuitry, it is possible to standardise the appliances so that one system can be used to charge a range of them. It is pointed out, with reference to any of the equipment referred to in the foregoing, and following, account, that one suggested trade name for any of the described solar powered systems is "TAKE CHARGE", which latter is named, herein, as a possible trade mark for such a system.

According to the present invention, one variant of the solar powered system is used for powering a lawnmower, and has the solar panel mountable on the roof, or the wall, of a shed, or the like, on a specially designed mounting panel which can itself be conveniently mounted and adjusted so that the solar cells receive the optimum energy from the sun during the daily rotation of the earth on its axis and during the yearly rotation of the earth around the sun. Electric current is transferred from the said solar panel via suitable cabling, e.g. a cable having, at one end, a male plug which plugs into a female socket on the mounting panel (with further internal connection to the solar cells) and at the other end, a female socket which connects with a male plug system located at an electrical inlet to the interior of the said shed or the like. A suitable female socket, which forms part of the inlet, and which is located inside the said shed or the like, accepts a male plug which is connected by suitable cabling to an electrical interface which can be connected to at least one removable, rechargeable battery system, located inside the lawnmower, wherein, in one variant of the system, the said battery system supplies current to a direct current motor, and in another variant of the system, the battery system supplies current to an inverter which then supplies current to an alternating current motor, and wherein the said electrical interface contains electronic circuitry for controlling the flow of current to the battery system. In any variant of the system, an indicator lamp system shows that the correct state of charge of the battery system has been attained. This could be red for charging and green for fully charged. Other variants of the indicator system can utilise a colour changing method to indicate a state of charge from complete discharge, through partial charge, to full charge. Alternatively, a Light Emitting Diode (LED) bar display could be utilised.

It is to be noted that particular care has to be taken to ensure that electrical safety standards are met throughout; especially due to the prevailing "outdoors" environment for the solar panel.

The battery system of the lawnmower is thus charged between mowing cycles, which, in the summer season tends to be approximately from two to three weeks, and is therefore totally adequate for fully charging the battery system utilised in the system.

Thus, by using solar panels to charge the batteries between uses, rather than powering the device directly via solar charging, both solar panel size, and cost, can be minimised.

In order to describe the invention in more detail, reference will now be made to the accompanying diagrams in which: Figure 1 shows, in schematic form, a three-dimensional diagram of externally visible embodiments of the invention.

Figure 2 shows, in schematic form, a three-dimensional diagram of internally and externally visible embodiments of the invention.

Figure 3 shows, in schematic form, a detailed three-dimensional diagram of internally and externally visible embodiments of the invention.

Figure 4 shows, in schematic form, a three-dimensional diagram of internally visible embodiments of the invention inside a lawmnower.

Figure 5, shows, in schematic form, a simplified, two-dimensional plan view of embodiments of the solar powered system.

Figure 6, in schematic form, a simplified two-dimensional plan view of elements of the solar powered system.

Figure 7 shows, in schematic form, a three-dimensional diagram of externally visible embodiments of the invention which provide for adjustment of the orientation of the solar panel.

With reference to Figure 1, which represents a schematic three-dimensional view, a shed, 1, has roof-mounted solar panel system, 2, which is connected, via i) external cabling, 3, ii) outside connector assembly, 4, and iii) internal cabling, 5, to a lawnmower system, 6 (not shown in the diagram).

S

With reference to Figure 2, which represents a schematic, three-dimensional view, the shed, 1, already described with reference to Figure 1, is shown as viewed from the rear, and with the inset detailed view, showing the lawnmower, 6, connected, via the internal wiring, 5, to outside connector assembly, 4.

With reference to Figure 3, which represents a schematic, three-dimensional view, the shed, 1, already described with reference to Figure 2, is shown again as viewed from the rear, but with the detailed view showing an alternative view of the lawnmower, 6, internal cabling, 5, and the outside connector, 4.

With reference to Figure 4, which represents a schematic, three-dimensional view, the lawnmower, 6, already referred to, with reference to Figures 1, 2, and 3, has a rechargeable battery system, 7 (located on battery mounting and securing tray, 8) which can be connected internally to connector system, 9, via cabling (not shown in the diagram) wherein the connector system is utilised for connecting the rechargeable battery system to the current supply from the solar panel, via an electrical interface, I (not shown in the diagram) and internal and external cabling, already described with reference to Figure 1.

With further reference to Figure 4, an electric motor, 10, is connected to the rechargeable battery system, 7, via conditioning circuitry (not shown in the diagram) wherein, in addition to driving the cutting blade, 11, the said motor can also serve as the means for providing lift for the lawnmower where the lawnmower is of the hover type. The motor, 10, thus has a grass cutting blade, 11, connected to its lower driving shaft, and an opening, 12, allows for contact with the grass. It is pointed out, with reference to the foregoing, that the grass box and other ancillary equipment are not shown in the diagram.

With reference to Figure 5, which represents a simplified, schematic, two-dimensional plan view of elements of the solar powered system; this shows the various components of the variant of the system which utilises a rechargeable battery system, 7, to provide electric power to the direct current motor, 10, of the lawnmower. Thus, electric current from the roof-mounted solar panel, 2 (not shown in the diagram) is taken, via external cabling, 3 (not shown in the diagram) to outside connector assembly, 4, mounted in the wall, W, of the shed, and then, via internal cabling, 5, to electrical interface, I, which supplies electronically conditioned, direct current, to rechargeable battery system, 7, mounted in tray, 8, of the lawnmower, 6, via connector, 9. An appropriate safety switch system (not shown in the diagram) then supplies direct current from the rechargeable battery, 7, to the motor, 10, of the lawnmower. The switch system is of the type which requires one button to be held in via a finger of one hand, whilst fingers of the other hand pull a lever in, thereby latching the switch into its on position, whereupon the button can then be released but with the supply of current to the motor, 10, maintained. Release of the lever then disconnects the supply to the motor, 10. The switch system is preferably mounted on the handle of the lawnmower (neither shown in the diagram).

With reference to Figure 6, which represents a simplified, schematic, two-dimensional plan view of elements of the solar powered system; this shows the various components of the variant of the system which utilises a rechargeable battery system, 7, to provide electric power, via an inverter, 11, to the alternating current motor, 12, of the lawnmower, 6. Other elements shown in the diagram are as described with reference to Figure 5. It is pointed out, with reference to the use of the inverter, 11, that, since alternating current at the mains supply voltage of 240 volts is involved, due precautions need to be taken with regard to electrical safety. Thus double insulation is essential and the safety switch system already described with reference to Figure 5, should be utilised. Also, the rechargeable battery system, 7, needs to be isolatable from the inverter, 11, by means an appropriate plug and socket arrangement, as do the inverter, 11, and the alternating current motor, 12.

In order to ensure that the solar cells receive the optImum energy from the sun during the daily rotation of the earth on its axis, the mounting panel containing the solar panel is provided with three axes, wherein the orientation of a second axis with respect to a first axis is always 90 degrees. By adjusting the first axis about a third axis so that the first axis is parallel with the polar axis of the earth, and by rotating the mounting panel about the second axis so that its contained solar panel receives radiation from the Sun at right angles with its plane surface, rotation of the mounting panel about the first axis in a direction opposite to that of the rotation of the Earth about its axis, compensates for the rotation of the Earth on its axis, thereby maintaining a constancy in the direction of the radiation received by the solar panel from the Sun. Whilst it is cheaper and more convenient to arrange for the mounting panel, and hence the solar panel, to be set to receive radiation in a direction midway between the position of the Sun at sunrise and sunset, a motorised system will provide constant correction for the rotation of the Earth on its axis. It is pointed out, with reference to the foregoing, that rotation about the second axis can be arranged to be manually lockable but that this rotation could also be motorised.

With reference to Figure 7, which shows, in schematic form, a three-dimensional diagram of externally visible embodiments of the invention, this is similar to Figure 1, but shows the solar panel system, 2, connected to a mounting system, 13, which allows for orientation of the solar panel as already described in the preceding paragraph.

Thus, with further reference to Figure 7, the system is set up by rotating the first axis, 14, about the third axis, 16, until the first axis is parallel with the Polar axis of the Earth. The solar panel, 2, is then rotated about the second axis, 15, until it receives radiation from the Sun at right angles to the plane surface of its set of solar cells, and therefore receives the maximum radiation from the Sun. The mounting system, 13, thus allows the solar panel system to be orientated in order to receive the maximum energy from the Sun in the same way that a telescope can be arranged to follow the apparent motion of a star by mounting it on an equatorial mount.

Claims

CLAIMS1. A solar powered system, wherein electricity provided by solar cells which form part of the said system can be supplied to at least one electrical appliance.
2. A solar powered system as claimed in claim 1, wherein the said solar cells are situated in a specially designed mounting panel which can be conveniently mounted and adjusted so that the solar cells receive the optimum energy from the sun during the daily rotation of the earth on its axis and during the yearly rotation of the earth around the sun.
3. A solar powered system as claimed in claim 2, wherein the said mounting panel containing the solar panel can be adjusted about three axes, wherein the orientation of a second axis with respect to a first axis is always 90 degrees and wherein, by is adjusting the first axis about a third axis, so that the first axis is parallel with the polar axis of the earth, and by rotating the said mounting panel about the second axis so that its contained solar panel receives radiation from the Sun at right angles with its plane surface, rotation of the mounting panel about the first axis in a direction opposite to that of the rotation of the Earth about its axis, compensates for the rotation of the Earth on its axis, thereby maintaining a constancy in the direction of the radiation received by the solar panel from the Sun.
4. A solar powered system as claimed in claim 3, wherein rotation about each said axis is lockable, and wherein adjustment can be either purely mechanical or motorised.
5. A solar powered system as claimed in claim 4, wherein the solar cells are separate from the appliance, thereby allowing charging to be carried out via a variety of different configurations of i) solar panel, ii) charging system, and iii) appliance and wherein, in the case of an appliance such as a lawnmower, the weight of the operated lawnmower is minimised, and this reduces the power requirement for any particular combination of electric motor and rechargeable battery.
6. A solar powered system as claimed in claim 5, wherein by careful design of any appliance which utilises rechargeable batteries, e.g. the vacuum cleaner, the food mixer, the electric drill, the strimmer, or hedge trimmer, etc., and by careful design of the system of i) solar cells, ii) rechargeable batteries, and iii) associated circuitry, it is possible to standardise the appliances so that one system can be used to charge a range of them.
7. A solar powered system, constructed and arranged to operate substantially as hereinbefore described with reference to any one of the embodiments illustrated in Figures 1 to 7, of the accompanying drawings.