GB2492603A

GB2492603A - Electrical time switch

Info

Publication number: GB2492603A
Application number: GB201111766A
Authority: GB
Inventors: Nicola Caroline Ternan Harris; Graham Henry Day
Original assignee: Individual
Current assignee: Individual
Priority date: 2011-07-08
Filing date: 2011-07-08
Publication date: 2013-01-09
Also published as: GB201211329D0; GB201111766D0; GB2492637A

Abstract

A device for controlling the supply of electrical power to connected equipment by definition of time periods for potential activity does not automatically provide supply to the equipment and comprises timer circuitry and an associated manual switch controlling actual activity. The potentially active time-period makes power available but does not connect power to equipment without operation of manual switching and returns it to an off condition at the end of the timed active period. Time periods are controlled by timer circuit (fig 2,14) enabling switch 9 to supply power to the connected equipment via terminals 5. Switch 10 allows termination of supply to equipment. The housing of the device can be a power connector having plug pins 2 for a conventional socket and the equipment can be supplied by either being directly wired to it, through a socket, or the device may be incorporated into the equipment. Programming of the timer may require a security code or a mechanical or magnetic key to prevent unauthorised access and the imminent end of a period of potential activity can be signalled by adjustable audible or visual means.

Description

IMPROVED ELECTRICAL TIMES WITCH

Field of the Invention

The present invention relates to improved time controlled electrical switching

Background to the invention

Many electrical devices, in both domestic and commercial situations, are controlled by external timeswitches to define the time periods when they are, or may be, active.

These switches are of varying complexity but all operate by enabling the electrical power supply to connected equipment during preset time periods. During these periods the connected equipment is either activated automatically or is capable of being activated manually: a lamp connected to such a switch, for example, will activate automatically if it is either unswitched or left switched on, or it may be manually controlled if fitted with its own switch.

In certain circumstances a greater degree of control is desirable and the standard type of switch has some disadvantages: the equipment will be enabled in the same state as it was left when the previous period ended, which may not be desirable, and in some circumstances the time period settings may be overridden by an unauthorised user.

The aim of this invention is to provide a timeswitch which disconnects the power supply to connected equipment at the end of an active period, but does not restore it unless a deliberate action is taken, There is considerable potential environmental benefit from the reduction in power consumption if equipment is not left powered up unless actually in use, and most equipment other than computers can safely be controlled by a tinieswitch. Equipment controlled by this invention in a school or office, for example, would automatically be switched off at the end of each day, and would not operate pointlessly at weekends or during holidays unless deliberately activated. In a domestic environment the invention could be used to ensure compliance with a lights out' time by a child absorbed in a book without causing the light to come on again the following day until it is needed.

The invention therefore offers additional environmental benefits compared to a normal timeswitch.

Summary of the invention

According to the present invention the solution lies in a device which allows activation of the connected equipment during the preset periods but does not itself cause such activation. Preferably the device requires a key or access code to amend the preset times, and preferably it is hard-wired to the equipment so that its operation may not be evaded by moving the power connection to an uncontrolled outlet.

The device comprises timer circuitry and power switching components to which the controlled equipment can be connected preferably via wiring terminals. Preferably the timer is of an electronic type and access to its controls is restricted by a requirement for the use of an access code or a mechanical or magnetic key.

When the output of the tinier circuitry is active non-locking on' and off' switches mounted on the device allow the power output to the connected equipment to be activated and de-activated as required. At the end of the active period the power output returns to its de-activated condition and remains in this condition until the on' switch is again used whilst the timer output is active.

Description of the preferred embodiment

The invention will now be exemplified with reference to the accompanying drawings in which: Figure 1 is a perspective partly exploded view of a timeswitch unit in accordance with the invention and Figure 2 is a possible circuit schematic of the unit.

The embodiment shown in figures 1 & 2 represents currently the best method known to the applicant of putting the invention into practice, but is not the only way in which this could be achieved. It is illustrated and will now be described by way of example only.

Figure 1 illustrates a device comprising a housing 1, of plastic construction, with protruding pins 2 of a size, shape, spacing, material and orientation suitable to function as a UK 13A plug to BS1363. The power cord 3 of the controlled device enters the housing via an opening into an access chamber and is secured by an appropriate strain relief 4. The cord is terminated to terminals 5 and the access chamber protected and shielded by cover 6.

The control circuitry is housed within the main body of the housing 1. In the particular example shown the display 7 and control switches 8 for the timer circuit 14 are mounted on the top face of the housing for easy access when programming. The operation of the control switches is inhibited by reed switch 11 which is located inside the housing 1 at a convenient point (marked on the particular example shown by a cross inside a circle). The reed switch 11 is closed by the application and holding in position of a small magnet at the marked point and programming of the timer can proceed. When the magnet is removed no amendments are possible until it is re-applied, so that unauthorised changes are prevented.

The timer is an electronic circuit comprising a digital clock capable of being programmed to produce an output voltage (ON) for the duration of one or a number of periods of time during the day. If during a period when the timer circuitry is ON the normally open on' switch 9 is pressed the timer output voltage is briefly connected to the coil of a relay 12 causing its contacts to close. The timer output voltage is also routed through the normally closed off' switch 10 to one of the two sets of relay contacts and thence, when the relay is activated, to the relay coil. Briefly closing the on' switch 9 will therefore cause the relay to latch on, passing the mains electrical power via the second set of relay contacts to the output terminals 5 and thus to the controlled equipment. A brief press of the normally closed off" switch 10 will break the circuit connecting the timer output voltage to the relay coil, and the relay will de-activate, disconnecting the power to the controlled equipment. These operations may be performed as many times as required whilst the timer is in its ON state.

At the end of the designated ON period of the timer circuitry the relay coil will no longer be supplied with the required voltage to keep it activated and it will return to its rest' position, disconnecting the mains power supply to the controlled equipment.

The unit thus allows the controlled equipment to be used normally during the preset periods of time, but requires deliberate manual activation so that the equipment will not automatically function and use power unless actually required. Unlike conventional plug-in timeswitches this unit is hard-wired to the controlled equipment so that bypassing the timer by plugging in elsewhere is not possible, and unauthorised re-programming is also prevented. Optionally an audible or visual warning of the imminent end of an active period could be incorporated. An accessible flise 13 is incorporated into the unit, as the housing serves also as a 13A plug to BS1363.

Claims

<claim-text>CLAIMS1. A device for controlling the supply of electrical power to connected equipment by definition of time periods for potential activity but not providing automatic supply to the equipment comprising timer circuitry and associated manual switch(es) controlling actual activity.</claim-text> <claim-text>2. A device according to claim 1 in which the housing of the equipment functions as a conventional electrical power connector.</claim-text> <claim-text>3. A device according to claim 1 in which the device is equipped with a directly wired electrical power input.</claim-text> <claim-text>4. A device according to claim 1 in which the device is incorporated into the controlled equipment.</claim-text> <claim-text>5. A device according to claim 1, 2 or 3 in which the controlled equipment is directly hard-wired to the device.</claim-text> <claim-text>6. A device according to claim 1, 2 or 3 in which the power output to the controlled equipment is connected via a conventional electrical socket.</claim-text> <claim-text>7. A device according to claim 1, 2, 3 or in which the programming functions of the timer circuitry are only accessible by entering a code to the timer.</claim-text> <claim-text>8. A device according to claim 1, 2, 3 or 4 in which the programming functions of the timer circuitry are only accessible by use of a mechanical or magnetic key.</claim-text> <claim-text>9. A device according to any preceding claim in which the imminent end of a period of potential activity is signalled by audible or visual means.</claim-text> <claim-text>10. A device according to claim 8 in which the warning signal is adjustable in nature, timing or level.</claim-text> <claim-text>11. Apparatus substantially as described herein with reference to and as illustrated in the accompanying drawings.</claim-text>