GB2451817A

GB2451817A - Solar charger for a portable electrical device

Info

Publication number: GB2451817A
Application number: GB0715700A
Authority: GB
Inventors: Dean Karl Phillips
Original assignee: Individual
Current assignee: Individual
Priority date: 2007-08-11
Filing date: 2007-08-11
Publication date: 2009-02-18
Also published as: GB0715700D0

Abstract

A solar charger 3 is securable to an electronic device such as a mobile telephone 1 by a self-adhesive member and includes a photovoltaic cell 4 and a connector lead 6 that can be inserted into the dc power socket 2 of the mobile telephone 1. Light energy is converted into electrical energy by the photovoltaic cell 4 and this electrical energy is used to trickle charge the storage battery of the mobile telephone 1. The solar charger is also useful for hands-free and Bluetooth¹ devices, personal digital assistants (PDAs), handheld computers, DVD players, CD players, games machines, laptop and notebook computers, MP3 players, digital cameras, camcorders, satellite navigation systems, and electronic toys.

Description

TITLE

Solar chargers for electronic devices

DESCRIPTION

Technical Field

The present invention relates to solar chargers, and in particular to solar chargers that can be used to trickle charge the storage battery of electronic devices.

Background Art

Many electronic devices are powered by rechargeable storage batteries. When the storage battery is depleted it can be recharged through a dc power socket provided on the electronic device. The storage battery is normally recharged using a conventional charger that can be plugged directly into the mains electricity supply or the dc power socket of a motor vehicle, for example. The additional energy demands of modem electronic devices means that storage batteries are often depleted very quickly and therefore need to be recharged at increasingly frequent intervals, which is inconvenient for the user.

Summary of the Invention

The present invention aims to address this problem by providing a solar charger securable to an electronic device by a self-adhesive member and comprising a photovoltaic cell (or solar cell) and a connector lead that can be inserted into the dc power socket of the electronic device such that the electrical energy generated by the photovoltaic cell is used to trickle charge the storage battery of the electronic device.

The solar charger is designed to be entirely self-contained, lightweight and cost-effective to produce. It can be retro-fitted to any electronic device because it makes use of the dc power socket that enables the storage battery to be recharged using a conventional charger. It is believed that the solar charger will be particularly useful for portable electronic devices such as inter a/ia mobile telephones and mobile telephone accessories like hands-free and Bluetooth� devices; personal digital assistants (PDAs); handheld electronic devices such as handheld computers, DVD players, CD players and game machines; laptop and notebook computers; MP3 players; digital cameras and camcorders; satellite navigation systems; and electronic toys.

The purpose of the solar charger is to supply electrical energy to the storage battery at a low rate whenever the photovoltaic cell is able to convert light energy. The additional electrical energy provided by the solar charger will reduce the rate at which the storage battery is depleted so that it will not need to be recharged as frequently.

The solar charger can also be used to reduce the self-discharge effects of the storage battery when the electronic device is not being used and help to meet the additional energy demands of the electronic device when it is.

The trickle charge rate will be substantially lower than the normal recharge rate.

However, the solar charger is not intended to he a replacement for the conventional charger and it will be readily appreciated that the storage battery of the electronic device will still need to be recharged in the usual way. The trickle charge provided by the solar charger will extend the lifetime of the storage battery between each proper recharge. In the case where the electronic device is a mobile telephone then the solar charger may provide up to about 60% more talk time, for example. In other words, a storage battery that would normally allow the mobile telephone to be operated for 4 hours before it was fully depleted can provide an additional 1.5 hours of use if the solar charger is secured to the mobile telephone and the connector lead is inserted into the dc power socket.

The photovoltaic cell can be flexible to allow it to fit against a contoured outer surface of the electronic device. The size, shape and configuration of the photovoltaic cell may be selected according to the energy requirements and the storage battery characteristics of the electronic device. More particularly, the size of the photovoltaic cell (or the number of individual photovoltaic cells) can be selected to provide the required amount of trickle charge for a particular storage battery. For an electronic device having a 3.7 V storage battery, the photovoltaic cell of the solar charger might be configured to provide 3 V (400 mA) trickle charge, for example.

The self-adhesive member may take the form of a self-adhesive pad or strip and enables the user to secure the solar charger directly to the electronic device. The self-adhesive member may be provided with a backing sheet that can be peeled off by the user to expose the adhesive layer.

The photovoltaic cell can be retained in a casing that also houses any associated circuit components such as a blocking diode. In this case, the self-adhesive member may be attached to, or form a part of, the casing. If the photovoltaic cell is flexible then the casing will also be flexible and may be made of a thin plastics material, for

example.

The solar charger is secured by the user to an outer surface of the electronic device using the self-adhesive member, preferably in a location where it will receive the maximum amount of exposure to light when the electronic device is being used. The connector lead is connected to the photovoltaic device (optionally through the associated circuit components) and the free end will include a conventional power plug that corresponds to the dc power socket of the electronic device. The power plug is inserted into the dc power socket of the electronic device so that the electrical energy produced by the photovoltaic cell is supplied directly to the storage battery of the electronic device. When the storage battery is depleted, the power plug can be removed from the dc power socket of the electronic device to allow the storage battery to be recharged using a conventional charger.

The length of the connector lead can be chosen depending on the electronic device and the likely distance between the location of the photovoltaic cell and the dc power socket.

Drawings Figure 1 is a front of a solar charger according to the present invention secured to a mobile telephone; and Figure 2 is a side view of the solar charger of Figure 1 before it has been secured to the mobile telephone.

With reference to Figures 1 and 2, a solar charger 3 is shown secured to a mobile telephone 1. The mobile telephone 3 (which in practice could be any suitable electronic device) includes a dc power socket 2.

The solar charger 3 includes a solar cell unit 4 for converting light energy into electrical energy by known means. The solar cell unit 4 is retained in a casing 5 made of a plastics material. One end of the connector lead 6 is connected to the solar cell unit 4 and the other includes a conventional L-shaped power plug 7.

The casing 5 is secured to the front surface of the mobile telephone I by a self-adhesive pad 8. The adhesive surface of the pad 8 is exposed by peeling away a backing sheet 9 before it is adhered to the mobile telephone. The power plug 7 can then be inserted into the dc power socket 2 of the mobile telephone (as shown in dashed lines in Figure 1) so that the electrical energy provided by the solar cell unit 4 is supplied as a trickle charge to the storage battery (not shown) of the mobile telephone I. Once secured using the self-adhesive pad, the solar charger 3 effectively becomes an integral part of the mobile telephone 1 and converts available light energy into electrical energy to provide a trickle charge that extends the lifetime of the storage battery (and hence the amount of available talk time) when the mobile telephone is being used and when it is turned off or in a "standby" mode.

When the storage battery (not shown) of the mobile telephone I is depleted, the power plug 7 can be removed from the dc power socket 2 to allow the storage battery to be recharged using a conventional charger.

Claims

I. A solar charger securable to an electronic device by a self-adhesive member and comprising a photovoltaic cell and a connector lead that can be inserted into the dc power socket of the electronic device such that the electrical energy generated by the photovoltaic cell is used to trickle charge the storage battery of the electronic device.
2. A solar charger according to claim 1, wherein the photovoltaic cell is flexible.
3. A solar charger according to claim 1 or claim 2, wherein the photovoltaic cell is retained in a casing.
4. A portable electronic device comprising: a rechargeable storage battery; a dc power socket; and a solar charger secured to an outer surface of the electronic device by a self-adhesive member; wherein the solar charger includes a photovoltaic cell and a connector lead that can be inserted into the dc power socket of the electronic device such that the electrical energy generated by the photovoltaic cell is used to trickle charge the rechargeable storage battery of the electronic device.
5. A solar charger substantially as herein described and with reference to the drawing.