GB2252846A - Domestic remote control central heating and hot water control system - Google Patents

Abstract

A central heating and hot water control system comprises a mains-powered master control unit 500 which allows termination and direct operation of heating control hardware. The master control can be accessed remotely from any chosen room within a household by means of one or more slave control units 100A, 100B which plug into any convenient electrical mains socket, transmitting and receiving control information to and from the master unit with codes superimposed on the mains wiring system. A slave unit has the facility to become a chosen room's thermostat with visual temperature indication and set-point adjustment. The master unit operates as the hot water thermostat with visual temperature indication and two set-point adjustments: Normal, which is used for average non-scalding temperatures and High which can be selected temporarily and is annunciated on master and slave(s) when reached, for very hot water temperatures. The active slave unit at any time overrides existing control signals. Interference with similar control systems in neighbouring houses can be minimised by provision of a selectable coding used in data transmission. <IMAGE>

Description

DOMESTIC REMOTE CONTROL CENTRAL HEATING AND HOT WATER CONTROL SYSTEM This invention relates to a domestic remote control central heating and hot water control system.

Many differing forms of domestic central heating and hot water controllers are already in common use today, some featuring simple MANUAL control of the medium, i.e. the sensing and controlling being carried out by the occupant to suit his/her requirements, some being THERMOSTATICALLY controlled, that is, a temperature can be chosen and maintained automatically to suit the desired application; other forms of domestic heating control include NON-ELECTRICAL ELECTRONIC means, i.e.

thermostatic radiator valves relying on heat expansion as a direct control medium.

However, the above control systems have some inherent drawbacks: in the first case, MANUAL Control (ON/OFF occupier feed-back) requires constant vigilance to maintain, for example, that room heating is comfortable and that bath water is hot enough; also, the danger when relying on human judgment to leave the hot water on for too long, resulting in wasted energy, extra cost and the danger to young children with access to the hot taps.

In the second case, THERMOSTATIC control does have the advantage of automatically maintaining a desired temperature (within its differential switching points), but expense increases due to the addition of temperature sensors/ controllers that have to be purchased and installed in appropriate places. In the case of hot water control, a cylinder thermostat can be mounted on the hot water cylinder and maintain the chosen temperature set-point. In the case of room heating from a central heat source, a wall thermostat would be needed, wired and mounted in the desired room, other rooms relying on this as a master control. individual room sensors/thermostats require the further cost and inconvenience of extra wiring and a means of knowing which zone is occupied (P.I.R. etc.).

In the third case, NON-ELECTRICAL ELECTRONIC thermostatic type valves are increasing in popularist, as no wiring is required and individual temperature control is possible, when a single pumped heat source is used. They work by sensing the individual room's temperature and throttling the flow of the heating medium to meet the temperature set point selected.

The control action used is proportional only, and although reasonable temperature control can be maintained, they suffer from offset, a control term encountered when proportional control is used without integral action. Also, the pumped medium has to be switched on and off at some convenient location selected by the heating engineer, which is not always at a convenient location.

Most households with a central heating source use one or a combination of these controls above.

According to the present invention, there is provided a domestic remote control central heating and hot water control system which comprises:i. A control unit which can be mounted near the heating source or the hot water cylinder, and acts as the MASTER control panel, accessing typical control equipment and also acting as an electrical termination box for all ancillary wiring associated with central heating and hot water control hardware.

ii. A control unit which is remote from the master and acts as a SLAVE control by accessing the master controller's controls bb means of coded data superimposed on the household's mains electrical wiring.

The slave unit is provided with a visual digital thermometer which plugs into any convenient household mains socket and becomes that room's thermostat by switching the heat source ON/OFF to maintain the desired room temperature which is personally programmable and memorised within the slave unit.

More than one slave can be used as the master unit feeds back data about its dut and updates all the slaves, wherever situated throughout the household, provided they are on the same electrical phase and within transmission range.

The master unit is also provided with a isual digital thermometer and displays the hot water cylinder's temperature and becomes the hot water thermostat bp switching the heat source ON/OFF to maintain the desired NORMAL* hot water temperature setting, which is personally adjustable and memorised within the master control unit.

*NORMAL: A general purpose hot water temperature, which can be personally programmed to any desired temperature from 0 to 100 degrees Centigrade, but would ideally be set to a usable average value for general household duties, e.g. a comfortable hand washing temperature.

A second temperature set point is provided within the master controller and, sçhen selected, also acts as tie hot water cylinders thermostat b switching the heat source ON/OFF to meet the desired HIGH* hot water temperature setting. This higher temperature valve is also personally adjustable and memorised within the master unit. When the HIGH* temperature is reached, masters and slaves annunciate this via on-board audible units which alert householders that the target temperature has been reached. The audible warning stops automatically after a short time, or can be acknowledged on the master or slaves, leaving a visual indication as proof that the HIGH* temperature has been achieved.

Some advantages of this domestic remote control central heating and hot water control system would be: FLEXIBILITY: The flexibility of being able to operate central heating and hot water from any desired room/rooms throughout a house, provided the room/rooms have a mains socket on the same electrical phase as the master unit.

\-ERSAIILITS-: The mains-powered slave unit also becomes that room's thermostat. With simple push-button operation, the desired temperature can be programmed and plugged into a mains socket, allowing the main control zone to be altered for whatever reason, e.g. changing the main living room.

A batter back-up looks after the settings when the slave is unplugged, and temperature may still be read and the set point adjusted while unplugged CONVENIENCE: Another advantage is that, in large homes or multi-storey housing, more than one slave could be used (say, one on each floor) and would be of great benefit to persons with mobility problems, e.g. physical disability.

*HIGH: .t high temperature hot water value, which can be personally programmed to any desired temperature from 0 to 100 degrees Centigrade, but would ideally be set to the highest needed water temperature, e.g.

very hot water, baths etc.

ECONOMY: ith the said Normal* hot water thermostat setting adjusted to suit most household needs, e.g. washing dishes, clothes, and general duties, a saving may be made over conventional hot water control thermostats which are set to the highest needed temperature at all times.

The said High* thermostat setting can be adjusted to the highest needed temperature, and only when this said High* set point is selected does the water temperature rise to meet it.

Thus very high temperatures are only available with deliberate selection. The advantage of this is SAFETY, since very hot water is only available on demand, reducing scalding risks, especially to the elderly and young children with access to the hot taps.

INFORMATIVE FEATURE: With conventional hot water control, the assurance that a full tank of hot water is available, e.g. for a bath, can be a problem, especially if the hot water has been used up by some other person or appliance elsewhere in the household. This problem can be eliminated, as both master and slave/slaves give an audible and visual alert only when the said High* target temperature is achieved.

INSTALLATION.

SAVING: Advantages to both the heating engineer and the householder alike were the basis of this invention.

tie heating engineer's installation time and costs could be reduced, as only the boiler or hot water cylinder end of the system requires wiring since all the control hardware is terminated within the master unit itself.

In new homes, many plumbers install wall thermostats in the most frequently used room, while others insist on hallway as the optimum location. With this domestic remote control central heating and hot water control system, the heating engineer could offer the customer flexible options. Also, when installing a new system in an established "finished" house, disruption to household fittings, floors and walls etc. that typical room thermostat installations cause, can be totally avoided due to the transmission feature of this invention.

A specific embodiment of the invention will now be described by way of example with reference to the accompanying drawings, in WlliCll: FIG 1 Shows the facia of the slave control unit, with its L.C.D. display and control push switches.

FIG 2 Shows a side elevation of the slave control unit with its 13 Amp pins and temperature probe location.

FIG 3 Shows the rear elevation of the slave control unit with its audible alarm output location, and access to the U.I.D switches.

FIG 4 Shows the top elevation of the slave control unit.

FIG 5 Shows the facia of the master control unit, with its L.C.D. display and control push switches.

FIG 6 Sows a side elevation section of the master control unit with a means of splitting the main circuits from tie facia, for access to the hardware wiring terminal block.

FIG 7 Shows the master control unit, with the facia removed exposing the ancillary control hardware termination block.

FIG 8 Shows the principle of the slave/master operation features via a mains transmission link in block diagram form.

FIG 9 Shows a schematic diagram of three rooms of a typical household's ring main and central heating system, using a domestic remote control central heating and hot water control system.

With reference to the drawing, Fig 9 shows a simplified schematic diagram of a household's electrical ring main and a typical centrally heated ad hot water system with a master controller 500 and two slaves 100A and 100B. 901 is a Ras- fired boiler, 902 is a hot water cylinder, 903A, B + C are motorised ON/OFF control valves. 904A/B are individual room radiators. 905 is the water pump. It can be seen from this that the mains wiring within a typical household is an ideal data route around various rooms 900, provided that sophisticated electronic devices are employed.

The problems faced when using a mains data link include: Isolation of the high AC voltages from sensitive electronic transmitters and receivers, and data corruption from noisy supplies, which could interfere with the individual binary serial data stream which operate the various control functions of the system.

To overcome these problems, a dedicated mains R2f-TX chip similar to the LN 1893 National Semiconductor Carrier Current Transceiver should be employed, with optical isolation from the data electronics.

The added problem of interaction with other households using a mains data link system can be avoided with m domestic remote control hot water and central heating system, as provision is made within master and slaves to change the binary transmitted data codes for each function by selecting an individual U.I.D** Code on D.I.L. switches. Fig 7, 711 shows the master's U.I.D switches and Fig 3 301 shows the slaves' U.l.D.

switches.

With reference to the drawing, Fig 9 shows how typical central heating and hot water control hardware are terminated and powered from the master controller. The hot water temperature probe is bonded to the hot water cylinder 906 and terminates within the master controller, as shown by the dotted line 701.

With reference to the drawing, Fig 7 shows the terminal box section of the master control panel with its twenty terminals 700, where pins 1 and 2 locate the electrical temperature probe 701. Pins 3 and 4 are olt-free and are available for connection of an external audible device 702. Pins 5 and 6 are the hot water control output 703. Pins 7 and 8 are the central heating control output 704. Pins 9, 10 and 11 are a Volt-free chan,,e-o-er output, common to both central heating and hot water outputs, and will switch from normally open to normally closed when either central heating or hot water are switched on 705. Pins 12, 13, 14 and 15 are unused spares 707.Pins 16 and 17 are the mains input connections 708.

Pins 18, 19 and 20 are earth terminals 709. A cable/cord grip is provided 710, and a fuse 711.

With reference to the drawing, Fig 8 shows a block diagram of the electronic functions of the domestic remote control hot water and central heating system. The slave unit is depicted in the top half of the drawing and the master unit is depicted in the bottom half, connected via their respective RX/TX modules through the household ' s mains wiring.

An example of a function selection is as follows: The R.X/TS (Receive/Transmit) module 804 of the slave remains in receive mode until a latched function is selected from the FUNCTION SELECT UNIT 802. This function times out, during **U.I.D. Three binary weighted unit identifier D.I.L.

switches which set Up the RX/TX codes; thus master and slaves must have the same code selected for remote control operation in a given application.

which time an individual unique code is generated by the BINARY SERIAL ENCODER/DECODER 803 and thus transmitted by the RX/TX module via the mains wiring live and neutral to the RX/LX module 805 of the master control unit, which is also in the receive modes The serial data recovered from the master's RX/TX module 806 is decoded by the BINARY SERIAL ENCODER/ DECODER 806, and latches on the corresponding device in the master's FUNCTION SELECT UNIT 807. This is turn directly operates the control relay associated within the CONTROL RELAY BOX 809. The master's DISPLAY UNIT 808 then indicates the particular function selected.

The data latch of the slave's FUNCTION SELECT UNIT 802 reverts back to receive mode after a period of time which allows several consecutive bytes of serial data to be downloaded to the master; in this way, the serial bit data gets checked against itself, reducing any telemetry errors that might occur due to any mains bourne interference.

With this function now selected within the master's FUNCTION SELECT UNIT 807, it, too, times out a latch which allows the RX/TX module 805 to site to transmit mode (TX) and also selects a unique individual code within the BINARY SERIAL ENCODER/DECODER 806 corresponding to the function achieved, and feeds back this data via its RX/TX module 805 through the mains link to the slave's RX/TX module 804. The slave's BINARY SERIAL ENCODER/DECODER 803 receives this data (as the RS module has now reverted back to receive mode) and the decoded data operates the corresponding L.E.D., indicating that the selected function has been achieved.

As with the slave's FUNCTION SELECT UNIT 802, the master's FUNCTION SELECT UNIT 807 reverts back to receive mode after a period of time, which allows several consecutive bytes of serial data to be downloaded to the slave. The master and slave no remain in receive mode until a further function is accessed.

With reference to the drawing, Fig 1 shows the front of the slave control unit 100, with the L.C.D. display 102 and push button switches. Within the display section 101, the flush momentary push switch marked ' F' converts all temperature readings to degrees Fahrenheit and reverts back to degrees Centigrade when pressed again.

The flush momentary push switch marked " when pressed converts the temperature display to a twenty-four-hour clock, and reverts back to temperature when pressed again.

The flush momentary push switch marked 'S' when pressed displays the temperature set point, i.e. the desired temperature control point which can be raised or lowered to suit an individual's/room's temperature requirements b use of the flush momentary push switches + and -. When the 'S' button is pressed again, the display reverts back to the actual room temperature reading, as sensed by the probe 103.

The flush momentary push switches marked + and - also set up the twenty-four-hour clock when the 'T' button is operated.

These above displays and adjustments are independent of mains supply and can be carried out unplugged from its 13 Amp socket Fig 2 200.

With reference to the drawing, Fig 5 shows the front of the master control unit with its L.C.D. display 502 and push switches.

Within the display section 601, the flush momentary push switch marked ' F: converts all temperature readings to degrees Fahrenheit and reverts back to degrees Centigrade when pressed again.

The flush momentary push switch marked 'N', when pressed, displays the Normal* temperature set point, i.e. the desired temperature control point which is suitable for general hot water duties, and this temperature can be raised or lowered to suit an individual's average hot water temperature requirements by use of the flush momentary push switches marked + and -. When the 'N' button is pressed again, the display reverts back to the actual water cylinder's temperature reading, as sensed by the probe Fig 9 906.

The flush momentary push switch marked 'H1, when pressed, displays the High* temperature set point, i.e. the desired temperature control point which is set higher than the Normal* temperature and announces when that High* temperature setting is achieved. The High* temperature set point can also be raised or lowered to suit an individual's requirements by the flush momentary push switches marked + and -. When the 'H' button is pressed again, the display reverts back to the actual water cylinder's temperature reading, as sensed by the probe Fig 9 906.

These above displays and adjustments are independent of mains supply and can be carried out unpowered or with fuse removed, Fig 7 710.

With reference to the drawing, Fig 1 shows the facia of the slave unit with six push switches with integral L.E.D.

indicators 104. The three on the lower left-hand side are dedicated to the hot water control.

When the flush momentary push switch marked H/W OFF is pressed, a unique individual binary code is produced by the internal circuity of the slave and is transmitted via the household mains wiring system Fig 9 900 to the master control unit Fig 9 500. This unique binary code is received by the master controller's circuitry and, acting on the data received, switches the hot water system off, effectively deenergising the hot water's final output relay Fig 7 703.

When the hot water output relay de-energises, it, too, generates a unique individual binary code produced by the master controller's internal circuitry and is transmitted via the household' s mains wiring system back to the slave control unit 100 and, acting on the data received, illuminates the integral L.E.D. corresponding to the hot water button H/W OFF.

This completes a feed-back loop and will update all slaves on the same electrical phase within its transmission range.

When the flush momentary push switch marked HiW NORM is pressed, a unique binary code is produced by the internal circuitry of the slave controller, and is transmitted via the housellold's mains wiring system Fig 9 900 to the master control unit Fig 9 500. This unique binary code is received by the master controller's circuitry and, acting on the data received, selects the Normal* hot water set point within the master control unit, and effectively operates the hot water's final output relay Fig 7 703 with respect to the Normal* set point. When the Normal* temperature circuitry has been selected within the master unit, it, too, generates a unique individual binary code and is transmitted via the household's mains wiring system back to the slave control unit 100 and, acting on the data received, illuminates the integral L.E.D.

corresponding to the H/W NORM switch. This also completes a feed-back loop and will update all slaes on the same electrical phase within its transmission range.

When the flush momentary push switch marked H/W HI is pressed, a unique individual binary code is produced by the internal circuitry of the slave controller and is transmitted via the household's mains wiring system Fig 9 900 to the master control unit Fig 9 500. This unique binary code is received by the master controller's circuitry and, acting on the data received, selects the High* hot water set point within the master control unit and effectively operates the hot water's final output relay Fig 7 703 with respect to the High* set point. When the High* temperature circuitry has been selected within the master unit, it, too, generates a unique binary code and is transmitted via the household's mains wiring system back to the slave control unit 100 and, acting on the date received, illuminates the integral L.E.D. corresponding to the H/W HI switch. This also completes a feed-back loop and will update all slaves on the same electrical phse within its transmission range.

The only difference between H/W NORM and H/W HI selection is that, when H/W HI reaches its target temperature set point, the master control unit annunciates for a minute via its onboard audible unit 504, and makes the integral H/W HI L.E.D.

flash.

nique individual binary code is also produced by the internal circuitry of the master control unit 500 when this H/W HI set point is achieved, and transmitted via the household's mains wiring system Fig 9 900 to the slave unit 100. This unique binary code is received by the slave unit's circuitry and, acting on the data received, switches on the slave's on-board audible device Fig 3 300 and makes the integral L.E.D. corresponding to the H/W HI switch 104 flash.

The audible alert times out after a minute, just leaving the H/W HI L.E.D. flashing, as described for the master earlier.

The no flashing L.E.D.'s on both master and slave/slaves act as a visual indication that the High* water temperature has been reached, as the audible device may not have been heard.

The H/W HI L.E.D. 's on master and slave units continue to flash until a further hot water selection is made.

On the lower right-hand side of the slave unit Fig 1 are three switches dedicated to the central heating controls.

When the flush momentary push switch marked C/H OFF is pressed, a unique binary code is produced by the internal circuitry of the slave and is transmitted via the household's mains wiring system Fig 9 900 to the master control unit Fig 9 00. This unique binary code is receied by the master controller's circuitry and, acting on the data received, switches the central heating system off, effectively de energising the central heating's final output relay Fig 7 704.

When the central heating's output relay de-energises, it, too, generates a unique individual binary code produced by the master controller's circuitry and is transmitted via the household's mains wiring system back to the slave control unit 100 and, acting on the data received, illuminates the integral L.E.D. corresponding to the central heating button C/H OFF.

This completes a feed-back loop and will update all slaves on the same electrical phase within its transmission range.

When the flush momentary push switch marked CiH ON is pressed, a unique individual binary code is produced by the internal circuitry of the slave controller 100 and is transmitted via the household's mains wiring system to the master control unit Fig 5 500.

This unique binary code is received by the master controller's circuitry and, acting on the data received, switches the central heating system ON, effectively energising the central heating's final output relay Fig 7 704.

When the central heating output relay energises, it, too, venerates a unique individual binary code produced by the master controller's circuitry and is transmitted via the household's mains wiring system back to the slave control unit 100 and, acting on the data received, illuminates the integral L.E.D. corresponding to the central heating ON button C/H ON.

This also completes a feed-back loop, and will update all slaves on the same electrical phase within the transmission range.

This mode of operation has no thermostatic function and would be used where a household has thermostatic radiator valves fitted.

When the flush momentary push switch marked C/H STAT is pressed, the Integral L.E.D. on the slave 104, C/H STAT is latched on and a unique individual binary code is produced b the internal circuitry of the slave controller 100. This code is transmitted via the household's mains wiring system to the master control unit Fig 9 500 and any slaves throughout the household, provided they are on the same electrical phase and within the transmission range. This unique binary code is received b the master controller's circuitry and, acting on the data received, illuminates the C/H STAT L.E.D.. The same binary code de-latches any other slaves that were switched to C/H STAT, thus only allowing the last C/H STAT selection to be in control.The slave's temperature probe 10J compares the actual room temperature with the chosen set point selected in the display section 101 and transmits via the household's mains wiring system either the binary code for central heating ON or the binary code for central heating OFF, thus controlling the room's temperature automatically.

it can be seen from the above that only one slave can be in control as a room's thermostat at any one time; therefore, when more than one slave is used, the "controlled" room's slave must have its C/H STAT button pressed, thus disregarding any other C/H STAT selection. All other functions are common.

With reference to the drawing, Fig 5 shows the facia of the master unit with its flush momentary push switches and integral L.E.D. indicators 503. The three on the lower lefthand side are dedicated to the hot water control: H/W OFF, H/W NORM and H/W HI, and, when pressed, directly access the control circuits associated with their functions. These functions were described earlier in the description of the slave controller, and feed back the individual binary data to update the slave/slaves throughout the household.

The two switches on the lower right-hand side are dedicated to the central heating control C/H OFF, C/H ON, and when pressed, directly access the control circuits associated with their functions These functions were described earlier in the slave controller's description, and as described, feed back the individual binary data to update the slave/slaves throughout the household.

Directly above the flush momentary push switch marked C/H ON is on L.E.D. marked C/H STAT. This indicator illuminates if a slave is in central heating room thermostat mode, as mentioned in the earlier description of the slave controller.

With reference to the drawing, Fig 6 shows a section through the master control unit 500, indicating how the facia may be removed for access to the termination section Fig 7 700, U.I.D. switches 711, and fuse 710. Fig 6 shows how the master can be wall mounted. 602 is the area associated with the main electronics and output relays and a mtllti-pin socket 600, which accepts the plug 601, which is connected via a multicore cable to the membrane type push switch facia 603.

Claims (7)

1. DOMESTIC REMOTE CONTROL CENTRAL HEATING AND

   HOT WATER CONTROL SYSTEM CLAIMS 1. A domestic remote control central heating and hot water control system which comprises:

   i) A mains-powered control unit which can be mounted near the heating source or the hot water cylinder, and acts as the WASTER control panel by directly accessing typical central heating and hot water control equipment, and allows termination of all ancillary wiring associated with centrally heated control hardware such as pumps and motorised valves.

   ii) A control unit which is remote from the master and plugs into any electrical socket within a household, and acts as a SLAVE controller, by accessing the master controller's functions by means of coded data superimposed on the household's mains electrical wiring system. The slave controller is provided with a \'visual digital thermometer, and becomes a chosen room's tiiermostat by switching the heating source hardware ON/OFF via said coded data, to maintain a desired room temperature setting, which is personally programmable and memorised within the slave unit.

   slore than one slave unit can be used, as the master unit feeds back data about its duty, and updates all slaves wherever situated throughout a household provided they are on the same electrical phase and within transmission range.

   The master control unit is provided with a digital thermometer and displays the hot water temperature which is sensed by a temperature probe bonded to the hot water cylinder, and becomes the hot water thermostat bp switching the heat source hardware ON/OFF to maintain the desired NORMAL* hot water temperature set-point, which is personally programmable and memorised within the master control unit.

   *NORMAL: A general purpose hot water temperature, which can be personally programmed to any desired temperature from 0 to 100 degrees Centigrade, but would ideally be set to a usable average value for general household duties, e. g. a comfortable hand washing temperature.

   A second hot water temperature set-point is provided within the master control unit and, when selected, also acts as the hot water cylinder's thermostat b switching the heat source hardware ON/OFF to meet the desired HIGH* hot water temperature setting. This higher temperature valve is personally programmable and memorised within the master unit, and, when reached, master and slaves emit an audible and visual annunciation that said IIIGH* has been achieved.
2. 2. A domestic remote control central heating and hot water control system as claimed in Claim 1, wherein integral L. E. D. /push switches are provided on master and slaves to indicate functions selected and achieved.
3. 3. .N domestic remote control central heating and hot water control system as claimed in Claim 2, wherein unique binary codes are transmitted and received by the master and slaves' internal circuitry for each individual control function accessed, and for each individual function's feedback.
4. 4. A domestic remote control central heating and hot water control system as claimed in Claim 3, wherein provision is made for a working system's set of codes to be changed via unit identifier switches U.I.D., thus eliminating interaction with other systems on the same electrical phase that are within transmission range.
5. 5. A domestic remote control central heating and hot water control system as claimed in Claim 4, wherein a battery back-up is provided within master and slaves, so that temperatures can still be read and set-points can be maintained and/or adjusted when disconnected from the mains.
6. 6. A domestic remote control central heating and hot water control system as claimed in Claim 5, wherein audible devices are provided within master and slaves which provide an aural alert for approximately 60 seconds or until accepted on either master or slaves when the hot water has reached its HIGH* temperature set-point.
7. 7. A domestic remote control central heating and hot water control system substantially as described herein with reference to Figures 1-9 of the accompanying drawings.

   *HIGH: A high temperature hot water value, which can be personally programmed to any desired temperature from 0 to 100 degrees Centigrade, but would ideally be set to the highest needed water temperature, e.g.

   ver hot water, baths etc.