GB2350940A

GB2350940A - Electrical power supply

Info

Publication number: GB2350940A
Application number: GB9918718A
Authority: GB
Inventors: Roy Stephen Brown
Original assignee: Individual
Current assignee: Individual
Priority date: 1999-06-09
Filing date: 1999-08-10
Publication date: 2000-12-13
Anticipated expiration: 2019-08-10
Also published as: GB9913259D0; GB2350940B; GB9918718D0

Abstract

A Multiple Outlet Electrical Power Supply has a case (1), which contains the electronic circuit (2) to convert the 240v ac mains supply to a scaled down dc output supply. The electronic circuit (2), is connected to the mains supply by way of a power lead and plug (3). The output from the electronic circuit (2) is fed to the Multiple Outlet Electrical Power Supply connectors (4) via the connector selector controls (5). Multiple circuits can be fed from the Power Supply at any one time, for use in classroom situations and similar.

Description

2350940 TITLE Electrical Power Supply DESCRIPUON This invention relates to

electrical power supplies.

The invention was conceived to deal with the problem of how to allow many students in a classroom situation simultaneously to test electronics projects which they have built. One way of doing this would be to provide each student with a battery, such as a MN1604 (PP3) battery.

However, non-rechargeable batteries need to be replaced periodically, and rechargeable batteries (which are more expensive) need to be recharged periodically. Furthermore, unless the students' supervisor is vigilant, small batteries tend to be stolen by the students. Another solution would be to provide each student with a conventional mains adapter of the type having a housing which plugs directly into a mains outlet, and which has a low-voltage lead extending from the housing. However, each student then needs to work relatively close to a mains outlet, or many mains extension leads need to be employed. Also, again, unless the students' supervisor is vigilant, the mains adapters tend to be stolen by the students.

In accordance with one aspect of the present invention, there is provided a multiple electrical power supply, comprising a case, a circuit, a connection to a 240 V AC mains supply, output connectors, and selector controls for the output connectors.

In accordance with a second aspect of the present invention, there is provided a power supply comprising a housing, a mains-to-low-voltage converter circuit in the housing, means for connecting the converter circuit to the mains, and a plurality of low-voltage outlet connectors connected to the converter circuit.

In accordance with a third aspect of the present invention, there is provided a power supply comprising a housing suitable for standing on a work-surface, a plurality of low-voltage outlet connectors mounted on the housing to which a plurality of electrical circuits can be connected, an input for connection to a source of electricity, a manually- operable selector device mounted on the housing, and an electrical circuit contained in the housing and arranged to connect the input to the outlet connectors in a manner dependent on the setting of the selector device.

Preferred features of the invention are defined in the accompanying subsidiary claims.

A specific embodiment of the present invention will now be described, purely by way of example, with reference to the accompanying drawings, in which:

Figure I is a perspective view of a multiple outlet power supply; Figure 2 illustrates the connection of multiple devices to the multiple outlet power supply; and Figure 3 shows the control device being used to select the chosen outlets.

Referring to the drawings, the power supply comprises a case 1, an electronic circuit inside the case 1, a mains lead 3 and plug for connecting the power supply to a 240 V mains socket, output connectors 4 on the case 1, and a control device 5 for controlling the supply of power to the output connectors.

The electronic circuit inside the case I includes a mains to low-voltage step down transformer with one or more secondary windings and at least one bridge rectifier each with at least one smoothing capacitor. It may also include a fuse on the mains side, and at least one solid state voltage regulator and/or current regulator on the low-voltage side. The control device 5 may be switch which, in one position, supplies power only to the multiple outlet connectors 4 along the sides of the case I (for example to power up to ten students' low current consumption projects) and, in another position, supplies power only to the two outlet connectors 4 at the ends of the case I (for example to power a couple of students' higher current consumption projects). The control device 5, or another such control device 5, may be a potentiometer or switch for adjusting the output voltage at the connectors 4.

The case I is preferably larger than pocket-sized so as to deter pilfering, and may, for example, have a length of about 0.5 rn and a width of about 0.2 in.

In a modification to the embodiment of the invention described above, at least the transformer may be provided in a separate housing which is arranged to be plugged into a mains socket (like a conventional mains adapter), with a low-voltage cable connecting the separate housing to the case 1. The bridge rectifier and optionally the smoothing and regulating components may then also be provided in the separate housing. The low-voltage cable may be permanently connected to the case I so as to deter pilfering of the separate housing. Alternatively, the low-voltage cable may be arranged to be plugged into a socket on the case 1, so that a completely conventional mains adapter may be employed. In this case, it will be appreciated that that the students' supervisor merely needs to "keep an eye on" one mains adapter per multiple outlet power supply, rather than one mains adapter per student.

It should be noted that the embodiments of the invention has been described above purely by way of example and that many other modifications and developments may be made thereto within the scope of the present invention.

Claims

1. A power supply comprising a housing suitable for standing on a worksurface, a plurality of low-voltage outlet connectors mounted on the housing to which a plurality of electrical circuits can be connected, an input for connection to a source of electricity, a manually-operable selector device mounted on the housing, and an electrical circuit contained in the housing and arranged to connect the input to the outlet connectors in a manner dependent on the setting of the selector device.

2. A power supply as claimed in claim 1, further comprising a mains-tolowvoltage converter circuit in the housing.

3. A power supply as claimed in claim 1, further comprising a second housing containing a mains-to-low-voltage converter circuit, and a low-voltage cable connecting the converter circuit to the electrical circuit in the first-mentioned housing.

4. A power supply comprising a housing, a mains-to-low-yoltage converter circuit in the housing, means for connecting the converter circuit to the mains, and a plurality of lowvoltage outlet connectors connected to the converter circuit.

is

5. A power supply as claimed in claim 3, further comprising a manuallyoperable selector device mounted on the housing for selecting a manner of connection of the outlet connectors to the converter circuit.

6. A multiple electrical power supply, comprising a case, a circuit, a connection to a 240 V AC mains supply, output connectors, and a selector control for the output connectors.

7. A power supply as claimed in any preceding claim, wherein the selector device or control is arranged to select which of the outlet connectors is supplied.

8. A power supply as claimed in any preceding claim, wherein the selector device or control is arranged to select an output voltage for the outlet connectors.

9. A power supply as claimed in any preceding claim, wherein each outlet connector is a MN1604 (PP3) battery clip.

10. A power supply substantially as described with reference to the drawings.