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(11) | EP 0 373 958 A2 |
| (12) | EUROPEAN PATENT APPLICATION |
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| (54) | Time Controlled appliances |
| (57) A time controlled appliance e.g. an electric storage heater, is provided with means
1 for receiving a time coded broadcast signal, and with means 3,4,5,6,7 for controlling
the operation of the appliance in accordance with preset timing information which
has been set into the appliance. |
[0001] This invention relates to time controlled appliances and especially to time controlled domestic appliances such as cooking, heating and laundry appliances.
[0002] It is becoming increasingly popular to provide domestic appliances, especially cooking appliances, which can be operated manually or under program control. When program control is provided for, timing information is normally derived from a crystal source using the a.c. mains supply as the power source. In many applications, where an interruption in an operating program due to a mains failure cannot be tolerated, it is necessary to provide some form of battery back-up in order to maintain the timing information until the mains supply is restored. The cost of providing a battery back-up facility and the fact that batteries have only a finite life results in a less than ideal system. It is also necessary in present systems, to re-set the timing information in order to take account of, for example, the change to and from British Summer Time (BST).
[0003] It is an object of the present invention to provide an improved form of time controlled appliance which obviates the need for a crystal source and a battery back-up.
[0004] The British Broadcasting Corporation (BBC) make use of their long wave radio broadcast transmission, which operates at a frequency of 198 kHz, to transmit digitally encoded time and other information without disturbance to the normal, Radio 4, program transmission. This low frequency (LF) transmission offers national coverage for a number of low-bit-rate data channels, one of which is used to transmit a time code which is accurately defined on a minute-by-minute basis.
[0005] It is an object of the present invention to provide a time controlled appliance with means for receiving the long wave radio broadcast transmission and to use the time coded information in order to derive the required timing information.
[0006] According to the present invention, there is provided a time controlled appliance comprising means for receiving a time coded radiated signal, means for deriving timing signals from said received signal, and processor means operable on said timing signals for effecting switching of said appliance in accordance with program means set into said processor means.
[0007] In carrying out the invention, there may be provided aerial means for receiving said radiated signal, a radio frequency tuner operable on the output of said aerial means, decoder means operable on the output of said tuner for affording timing signals and comparator means for comparing said timing signals with programmed timing signals for effecting switching of said appliance.
[0008] In one arrangement, the aerial means may be effective for receiving a broadcast signal which is phase modulated with time coded information, the decoder means taking the form of a phase decoder for affording said timing signals.
[0010] The time controlled appliance may take any convenient form, such as, for example, a cooking appliance, heating appliance, laundry appliance or dish washing appliance.
[0011] An exemplary embodiment of the invention will now be described reference being made to the accompanying single figure drawing which is a block schematic diagram of a timing circuit arrangement for use in an electric storage fan-heater appliance in accordance with the present invention.
[0012] Normally, switching of electric storage heaters is effected by means of a switch unit which is installed adjacent the electricity board meter which is used to monitor electricity consumption. The switch unit is used to switch all the electric storage heaters connected in a particular installation, and it is not possible to individually control the charging time of any particular storage heater.
[0013] The timing circuit arrangement shown in the drawing is designed to be incorporated in an electric storage fan-heater appliance for individually controlling the on/off times that the storage heater is connected to the electrical mains, so that each storage heater may be controlled independently of any other storage heaters which may be connected to the same system. In some situations, the fact each individual storage heater is independently controlled may obviate the need for the main switch unit.
[0014] The timing circuit arrangement shown in the drawing comprises a ferrite aerial 1 for receiving the long wave radio broadcast on 198 kHz transmitted by the BBC, the carrier of which is bi-phase modulated to provide a number of low-bit-rate data channels, one of which is used to transmit a time code which is accurately defined on a minute-by-minute basis.
[0015] The output from the aerial 1 is fed to a R.F. tuner circuit 2, tuned to the carrier frequency of 198 kHz, and the output of the tuner circuit 2 is fed to a phase decoder circuit 3 for deriving the actual timing information from the received signal. The output from the phase decoder circuit 3 is applied to a comparator circuit 4 which also receives timing information from a unit 5 which is preset with the on/off times that the particular storage heater is required to operate on. The preset timing information may be permanently set into the unit 5, e.g. hard wired, or it may be stored on a suitable memory so that it may be changed when required.
[0016] The output of the comparator circuit 4 is used to control an on/off switch 6 which connects the heater element or elements 7 of the storage heater to the electrical mains supply 8.
[0017] The storage heater will also incorporate a control for controlling the heat output, this typically consisting of a thermostat control 9, the output of which is applied to a fan/vent controller 10 in which it is compared with the output from a temperature sensor 11 and which controls a fan 12 and vent 13 of the storage heater. The storage heater may optionally be provided with a time display (not shown).
[0018] Since the timing information used in the timing circuit arrangement which has been described is derived from the broadcast signal, there is no necessity to provide the usual crystal source or any battery back-up.
[0019] Although the timing circuit arrangement that has been described is indicated as being an integral part of an electric storage fan-heater appliance, it should be appreciated that it could equally well be used in other forms of time controlled appliance, such as cookers, washing machines, drying machines, dish washing machines immersion heaters, etc.
[0020] Also, although a timing circuit arrangement has been described which makes use of the long wave radio broadcast on 198 kHz, it should be appreciated that other time coded broadcasts could equally well be used. For examplc, there is a broadcast from Rugby - MSF - on 600 kHz which could be used, although this is not transmitted twenty-four hours a day; a West German broadcast - MAINFLINGEN, or a United States broadcast - WWV which could be used.
[0021] Time controlled appliances as described have the particular advantage that they may be individually controlled to operate at any particular time of day, and the time of day will automatically be corrected in the event of any mains failure and also to take account of time changes, such as the change to and from British Summer Time. In addition, in the event that multiple tariff rates are introduced by the electricity boards, the switching ON and OFF of the appliances may be controlled, in order to minimise energy costs, and the appliances may also be arranged to form part of an overall system which may include electric/oil/gas/solid fuel appliances, which are all controlled on a real time basis in order to optimise energy use and minimise energy costs in dependence upon particular tariffs and other constraints which may be placed on the system at any particular point in time.
1. A time controlled appliance comprising means for receiving a time coded radiated
signal, means for deriving timing signals from said received signal, and processor
means operable on said timing signals for effecting switching of said appliance in
accordance with program means set into said processor means.
2. An appliance as claimed in claim 1, comprising aerial means for receiving said
radiated signal, a radio frequency tuner operable on the output of said aerial means,
decoder means operable on the output of said tuner for affording timing signals and
comparator means for comparing said timing signals with programmed timing signals
for effecting switching of said appliance.
3. An appliance as claimed in claim 2, in which the aerial means is effective for
receiving a broadcast signal which is phase modulated with time coded information,
the decoder means taking the form of a phase decoder for affording said timing signals.
4. An appliance as claimed in any preceding claim, comprising a time display operable
from said timing signals.
5. An appliance as claimed in any preceding claim in the form of a cooking appliance,
heating appliance, laundry appliance or dish washing appliance.