GB2050662A

GB2050662A - Power Supply Control

Info

Publication number: GB2050662A
Application number: GB8014978A
Authority: GB
Original assignee: Individual
Current assignee: Individual
Priority date: 1979-05-15
Filing date: 1980-05-06
Publication date: 1981-01-07

Abstract

An apparatus for controlling a number of electrical devices or appliances on domestic premises or industrial sites comprises a means of superimposing a frequency shift keyed control signal onto the mains electricity supply to the devices or appliances, at a frequency which is much higher than the mains electricity supply frequency, e.g. 150 kHz, to address a selected device or appliance. A master control (10) comprises a timing device (12) which can be a microprocessor, and a memory (14). <IMAGE>

Description

SPECIFICATION Improvements in or Relating to Electrical Power Supply Control Apparatus This invention relates to a method and apparatus for controlling the electrical power supply to one or more electrically powered appliances or machines. Essentially the method comprises super-imposing or modulating the mains supply with a signal or series of signals to control one or more appliances or machines which are powered by the mains supply so that the appliances or machines can be switched on or off at pre-determined times, the signal or series of signals being generated by a central controller, thereby avoiding the need for a number of separate time switches for each machine or appliance.

According to one aspect of the invention, there is provided a mains supply circuit, a master control means connected to said circuit and one or more individual control means connected to said circuit, the master control means comprising memory means, a timing means and code generating means and the or each individual control means comprising code decoding means and switch means arranged to connect or disconnect electrical power to or from an appliance or machine controlled by the respective individual control means, the code generated by the code generating means being carried by the mains supply in the mains supply circuit.

According to another aspect of the present invention there is provided a master control means arranged to be connected to a mains electricity circuit and one or more individual control means also arranged to be connected to said mains circuit to control respective electrical devices powered by said circuit, the master control means being able to generate command signals, which signals are capable of being carried on the mains circuit simultaneously with the mains supply to each of said individual control devices, each individual control device being capable of responding to said command signals to control the respective electrical devices.

The invention further comprises a master control means which is adapted to be connected to a mains supply circuit and one or more individual control means also adapted to be connected to said circuit, the master control means comprising memory means, timing means and code generating means and the or each individual control means comprising code decoding means and switch means. The timing means may comprise a micro-processor or a large scale integrated device or devices. The code generator may include a serial inter-face to convert the command signals from the memory and timing means into a serial form, and a variable frequency oscillator to produce a modulated carrier signal at a frequency higher than the mains frequency.

The master control means may also include a keyboard or switching device so that existing commands to the master control can be altered or fresh commands entered.

A display device may also be included to show commands entered and/or the current real time.

The master control means can also include a power supply circuit to provide D.C. power for the circuitry within the control means.

The code de-coding means of each individual control means may comprise a control signal decoder to separate the control code from the mains supply and decode this code to extract the commands issued by the central controller, an appliance programming means to generate an individual appliance address signal and a comparator to compare the address of each command with the individual appliance address.

The switch means which only responds if there is coincidence between the command address and the individual appliance address, may comprise a solid state switch, relay or other switch means, to those shown in Fig. 1.

The present invention will now be more particularly described with reference to the accompanying drawings in which Fig. 1 shows in diagrammatic form, one form of electrical power supply control apparatus according to the present invention, and Fig. 2 shows a developed form of the control apparatus shown in Fig. 1 in more detail.

Referring to Fig. 1 a mains supply 2, which in the U.K. is typically a 50H3 240V supply, to a domestic residence, factory or any other site where electricity is used, passes to the main circuit 4 via a low pass filter 6 and a meter and fuse box 8.

A master controller 10 is connected to the main circuit 4, either in a permanent arrangement or by a plug and socket, and comprises a clock 12, an externally programmable memory 14 and a code generator 16.

At locations along the main circuit 4 are arranged individual controllers 1 8 which comprise a code de-coder 20 and a switch 22. The individual controllers are located at the positions where power is tapped from the main current circuit and in a domestic residence, those positions will be the power sockets supplying power to appliances 24 such as a cooker, electric fires or storage heaters, an immersion heater, etc, 24.

The memory 14 in the master controller 10 contains the information relating to each appliance, e.g. a code identifying each appliance and the times of day at which the appliance should be switched on or off. The code generator 1 6 emits a series of signals either continuously or at regular intervals, the signals containing the information stored in the memory 14, relating to the time of day, as dictated by the clock 12, at which the signals are transmitted. The signals are either superimposed on the mains supply or modulate the mains supply. An essential feature of the present invention being that the mains supply carries the control signals. The control signals can be carried between the live and neutral lines of the mains supply.The code decoder 20 in each individual controller 18 is arranged to read the signals carried by the mains supply and when the individual controller recognises the identity code, it will respond to the remainder of the signal and the command can be either to switch on or switch off the respective appliance via the switch 1 8 or to not to take any action, to leave the switch 22 in its present condition. In order to prevent stray signals from inadvertently operating the appliances, each code de-coder can be arranged to operate the respective switch 22 when it has de-coded the same signal a pre-determined number of times e.g. three times.

The function of the low pass filter 6 is to allow the mains supply to pass, but to prevent the higher frequency signals from the master controller from passing out into the supply 2 and perhaps affecting other circuits containing a control apparatus according to the invention. It will be recognised that a control apparatus according to the invention can be applied to industrial processes as well as domestic use and the apparatus avoids the need of a separate time controller for each appliance or piece of industrial equipment, since the memory 1 4 serves the function of containing all the information which would otherwise be kept in the individual timeswitches.Also the information in the memory can be changed very rapidly to suit any change in conditions, e.g. as the seasons in the year change, the times at which domestic heaters are required will change and in controlling industrial processes such as heating and cooling apparatus, furnaces, heat treatment plant etc., the times at which such processes have to operate will change according to conditions.

The memory 14 can also be arranged so that the information can be altered remotely e.g. by telephone or by radio. One or more of the individual controllers 1 8 can have a coder which senses a parameter such as temperature or light level and sends an appropriate signal on the mains supply to be stored as information in the memory 14.

Referring to Fig. 2 in which similar components to those shown in Fig. 1 have been given the same reference numerals, the master control means 10 has a programmable electric control circuit in the form of a microprocessor 1 2 e.g.

RCA CDP 1802 which functions as a timing means and has other functions as described below, the memory 1 4 e.g. Intersil P2 114 in which are entered the control instructions and can be part of the microprocessor and the code generator 16, which inciudes a serial interface 1 6a e.g. RCA CD4034 and a frequency shift keying modulator 1 6b e.g. RCA CD4047. The serial interface 1 6a converts the command signals from the memory and timing means 12 and memory 14 into a serial form from a parallel form and the modulator 1 6b is programmed by the serial form signal to produce a modulated carrier signal at a frequency higher than the mains frequency e.g. 1 50KH3. This carrier signal is superimposed onto the mains supply wiring 4, which then carries it around the premises.The control means 10 also includes a keyboard 11 or other switching device which is used to alter or enter fresh commands to the control means, and a display device 13 to show the commands entered or the current real time. A power supply circuit 1 5 provides D.C. power for the circuitry within the control means 10.

Each controller 1 8 has code de-coder including a de-coder 20a to separate the control code from the mains supply and decodes this code to extract the commands issued by the central control means 10. The signal de-coder 20a can comprise a phase iocked loop e.g. RCA CD4046, and a serial interface, e.g. RCA CD4034 arranged to convert serial data back to parallel data. Also included is an appliance programming means 20b which generates an individual address signal and a comparator 20c which compares the address signal of each command with the address generated by the programming means 20b so that each controller 1 8 responds only to commands issued to it and not to commands issued to other controllers.The switching device 22 which can be a solid state switch, a relay or other means carries out any command issued to it provided there is coincidence between the command address and the individual appliance address signal. Each controller 1 8 has a power supply circuit 21 to provide D.C. power for the circuitry within the controller. The microprocessor 12 which can be in the form of a large scale integrated circuit device or devices also functions to produce the real time and commands on the display 13 and it encodes the commands entered on the keyboard 11 and passes the encoded commands to be stored in the memory 14.

Each instruction in the memory has an address code and a time code and the microprocessor constantly compares the time code of the instructions in the memory with the real time.

When coincidence occurs between the time code and the real time, the microprocessor instructs the code generator 1 6 to produce a modulated carrier signal in accordance with the instruction in the memory 1 4. This carrier signal passes to each of the individual controllers 1 8, but the carrier signal will only cause that controller to respond which has the same address code as the address code of the carrier signal.

Claims

1. A master control means arranged to be connected to a mains electricity circuit and one or more individual control means also arranged to be connected to said mains circuit to control respective electrical devices powered by said circuit being able to generate command signals which signals are capable of being carried on the mains circuit simultaneously with the mains supply to each of said individual control devices, each individual control device being capable of responding to said command signals to control the respective electrical devices.

2. A master control means as claimed in claim 1 in which the master control means comprises timing means, memory means in which are stored the command instructions for the electrical devices and code generating means to produce a modulated carrier signal in dependence of the command instruction at a frequency higher than the mains frequency, to be carried by the mains supply.

3. A master control means as claimed in claim 2 in which the command instructions stored in the memory include a time code and an address code.

4. A master control means as claimed in claim 2 in which the timing means forms part of a programmable electric control circuit, the master control means including instruction entering means by which command instructions can be encoded by the programmable electric control circuit and entered in the memory.

5. A master control means as claimed in claim 4 in which the programmable electric control circuit has means for comparing the time code of the command instructions with the real time generated by the timing means.

6. A master control means as claimed in claim 4 or claim 5 in which the programmable electric control circuit is in the form of a microprocessor or large scale integrated circuit.

7. A master control means as claimed in any one of the preceding claims in which the code generating means comprises a serial interface to convert the command signals from the memory and timing means into a serial form, and a frequency shift keying modulator to produce a modulated carrier signal at a frequency higher than the mains frequency.

8. A master control means as claimed in any one of the preceding claims in which each individual control means comprises a control signal decoder, an address signal generator, a comparator to compare the address code of the incoming signal with the address code of the respective individual control means, and switch means to control the electrical power to the respective electrical device.

9. A master control means as claimed in any one of the preceding claims in which each individual control means and the master control means has a D.C. power supply.

10. A mains supply circuit incorporating a master control means as claimed in any one of the preceding claims.

11. A mains supply circuit as claimed in claim 10 in which the supply circuit incorporates a low pass filter between the mains supply and the master control means.

12. A mains supply circuit as claimed in claim 10 or claim 11 in which the command signals are carried between the live and neutral lines of the mains circuit.

1 3. A master control means constructed and arranged for use and operation substantially as herein described, and with reference to Fig. 1 and 2 of the accompanying drawings.

14. A mains supply circuit including a master control means as claimed in claim 13.