AU620639B2 - Monitoring apparatus - Google Patents

Description

I U 1 J COMMONWEALTH OF AUSTRALIA Patents Act 1952 0 fI p t @1~ r a *1 0.

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(Patent Application Number PJ 0145) COMPLETE SPECIFICATION FOR THE INVENTION ENTITLED:- 09 60 S 0*

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"MONITORING APPARATUS" The following statement is a full description of this invention, including the best method of performing it known to me:- .1

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2 This invention relates to monitoring apparatus.

This invention has particular but not exclusive application to the monitoring of electrical power drawn from a wall outlet, and for illustrative purposes reference will be made to such application. However, it is to be understood that this invention could be used in other applications, such as power monitoring in switchboards, plug-in power outlets and appliances.

The availability and reliability of electric power i supply has resulted on consumers developing a dependence on 1 0 continued supply. For instance, many medical life-support o00. systems depend on the uninterrupted supply of electricity, while in domestic applications, frozen foods of considerable eeoc value may spoil if the supply of power to a freezer is interrupted and there is no warning of the interruption.

15 Power supplI interruptions to an appliance may occur 0 .0G.0 because of loss of supply to the wiring system feeding the 0 00 appliance, but many interruptions occur because of inadvertent withdrawal of plugs from sockets, or because of accidental switching-off of a power point.

The present invention aims to alleviate the above disadvantages and to provide monitoring apparatus which will be reliable and efficient in use. Other objects and advantages of this invention will hereinafter become apparent.

With the foregoing and other objects in view, this fi _i 1 3 invention in one aspect resides broadly in monitoring apparatus including:monitoring means for sensing an interruption to an electrical circuit; and alarm means operatively connected to the monitoring means for producing a warning of said interruption.

The alarm means may be of any desired form, such as a steady or flashing light, but it is preferred that the alarm 10 means include audible alarm means such as a buzzer whereby a I o user may be warned of an interruption to the electrical 00 circuit without the necessity to actively monitor the alarm 0o0 means. The alarm means may be mounted remote from the 0 monitoring means such that it may be brought adjacent a desired location, such as a location frequented by a user.

Preferably, however, the alarm means is mounted adjacent the

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4 0monitoring means whereby the location of the interruption may be indicated clearly.

The monitoring means may include electrical circuitry' for the measurement of current flow within the electrical circuit such that a warning may be produced of a cessation of 0 4 v power consumption by a load. It is preferred, however, that the monitoring means include switch position sensing means whereby opening of the switch circuit may be sensed and used for operating the alarm means.

The monitoring means may also include a socket for use

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4 with a plug-in electrical connecter, and connection integrity sensing means may be associated therewith in a form such as a connection sensing switch whereby the alarm means may be operated by movement of the connection plug away from the connection socket.

Alarm disabling means may be provided for disabling the alarm means to minimise false alarms following deliberate disconnection or de-energising of the plug-in connector.

o oe o0o The alarm means may be powered from the mains power 0o 10 supplied to the electrical circuit. If desired, power 000 Bo°° o storage means such as a battery may be provided for powering oo the alarm in the eveht of mains power failure. The alarm means may be adapted for emitting a continuous alarm signal, but it is preferred that the alarm means be adapted for o. 15 emitting an intermittent warning signal whereby the power 0 00 0 oo° consumption of the alarm means may be minimised such that SOOo relatively small power supply components may be used.

Suitably, the monitoring means is adapted for inclusion *within a general purpose power outlet or wall socket, and the 0 1 20 monitoring means is adapted for operating the alarm means upon switching of the power switch to the "off" position or on withdrawal of a power plug from the socket. Preferably, a disabling switch is included and 'is disposed in a position such that it is shielded from operation by an inserted power plug.- In a further aspect of this invention, an electrical j: i~3 power outlet is disclosed of the type having:a power outlet socket assembly into which a plug connector may be inserted; a power supply switch for controlling power supply through said outlet socket assembly, and alarm circuit means for activating an alarm, characterised in that:said alarm circuit means includes a first activating circuit incorporating said power supply switch and activated when said power supply switch is in its off position, a second activating circuit incorporating a plug sensing "0 0 switch held open when a plug connector is operatively plugged into said socket assembly, said second activating circuit .oo. being activated when a plug connector is not operatively plugged into said power outlet socket assembly, and an override switch for selectively disabling said alarm means.

o 00 0 a 7-I 1: rv qli 4 6 monitoring moans; and operating said monitorin r e detection of an In order that this invention may be more easily understood and put into practical effect, reference will now be made to the accompanying drawings which illustrate a preferred embodiment of the invention, wherein:- 0 FIG. 1 is a front view of a dual power outlet according to the invention.

10 FIG. 2 is a circuit diagram applicable to one of the 000o power outlets shown in FIG. 1, and o0 0 FIGS. 3 and 4 show circuit diagrams of a further embodiment of the invention.

The power outlet 10 shown in FIG. 1 includes a wall 0 15 plate 11 which conforms to the standard dimensions of conventional power outlets, and which carries power outlet S sockets 12 and 13, together with their respective power control switches 14 and 15. Plug-sensing switches 16 in the form of push-to-disconnect push buttons project from the wall 2 20 plate 11 between the active and neutral pins 20 and 21 of the sockets 12 and 13 where they may be activated by power plugs inserted into the latter. Alarm-disabling switches 22 are attached to the wall plate 11 behind or flush with apertures 2'3 disposed between the pins 20, 21 and 24 such that each is inaccessible when a power plug are inserted over the aperture 23, but may be operated by inserting an actuating rod through

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L ;ei /vw i 00oo o 0 00 0 0 0 D o a 0 00°06.

0 00 0 00 0000 ooooo 0 0 0000 "4 the aperture 23 when a plug is not inserted.

Referring now to FIG. 2, it will be seen that the power control switch 14 has its wiper 25 connected to the incoming power terminal 26. The "on" switch terminal 27 is joined to the active pin 20, while the "off" switch terminal 30 is connected to the buzzer assembly 31 through a first diode 32 and a voltage-dropping resistor 33. The plug-sensing switch 16 connects to the incoming power terminal 26 and to the voltage-dropping resistor 33 through a second diode 34. The 10 diodes 33 and 34 rectify the AC power to produce, in conjunction with the smoothing capacitor 35, DC power for the buzzer assembly 31, and co-operate to prevent power flow through the switches 14 and 16. The negative side of the buzzer assembly 31 is connected to the neutral power terminal 15 24 through a second voltage-dropping resistor 36. The buzzer assembly 31 connects to the speaker 40 through the alarmdisabling switch 22.

When the power outlet 10 is connected to the mains power with the power control switch 14 in the "off" position, or without a power plug (not shown) holding the plug-sensing switch 16 in the "on" position, power may flow to the buzzer assembly 31 through the first diode 32 or the second diode 34. If the alarm-disabling switch 22 is in the "on" position, the speaker 40 will be activated and an alarm will sound. When a power plug is inserted into the socket 12 and pushes the plug-sensing switch 16 into the "off" position, ooo 00 0 0 00 0 a o0 0 00 0 00 00 a 000 o 0o 0 0 C, 8 and when the power control switch 14 is switched the flow of power to the buzzer assembly 31 is interrupted, and the speaker 40 cannot sound.

If the power control switch is turned "off", or the power plug is partially-withdrawn from the socket 12, power flow to the buzzer assembly 31 is resumed, and the alarm will sound.

In the embodiment 50 shown in FIGS. 3 and 4, the power 'for operating the buzzer 51 is supplied through a series capacitor 52 and a rectifier bridge 53, the DC power being smoothed by a filter capacitor 54.

It will of course be realised that while the above has 4 been given by way of illustrative example of this invention, all such and other modifications and variations thereto as 15 would be apparent to persons skilled in the art are deemed to i c S S fall within the broad scope aid ambit of this invention as is defined in the appended claims.

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Claims (4)

1. A general purpose electrical outlet of the type having:- a power outlet socket assembly into which a plug connector may be inserted; a power supply switch for controlling power supply through said outlet socket assembly, and alarm circuit means for activating an alarm, characterised in that:- said alarm circuit means includes a first activating circuit incorporating said power supply switch and activated when said power supply switch is in its Sc off position, a second activating circuit incorporating a plug sensing I switch held open when a plug connector is operatively plugged 15 into said socket assembly, said second activating circuit being activated when a plug connector is not operatively plugged into said power outlet socket assembly, and C e t an override switch for selectively disabling said alarm C C CL means. t t C c,

2. A general purpose electrical outlet as defined in Claim I, wherein said override switch is disposed in a position such ctt that its actuation member is shielded when a plug connector is operatively plugged into said power outlet socket assembly.

3. A general purpose electrical outlet as defined in Claim 2, I wherein said power outlet socket assembly is a wall socket.

4. A general purpose electrical outlet as defined in Claim 3, ,AAV; 4ld I~ E wherein said alarm means includes audible alarm means. A general purpose electrical outlet as defined in Claim 4, and including power storage means for powering said alarm means and power supply interruption detection means for operating said alarm means in response to a power failure. DATED this TWENTY-EIGHTH day of NOVEMBER 1991. VICTOR FRANK PENNISI by PIZZEY COMPANY PATENT ATTORNEYS 0 0 00 0 a SDo Spq 00 0 0 0 0 00 P 0* 0 0ap sr009 0-s 0a 0 0 00 no 0 0 00 C, a 00 0 '0a 0 *o 0