AU2012203895B2

AU2012203895B2 - Barbeque control system

Info

Publication number: AU2012203895B2
Application number: AU2012203895A
Authority: AU
Inventors: Graeme Geoffrey Kneebone
Original assignee: Furphys Foundry Sales Pty Ltd
Current assignee: Furphy's Foundry Sales Pty Ltd
Priority date: 2011-07-12
Filing date: 2012-07-03
Publication date: 2016-04-21
Anticipated expiration: 2032-07-03
Also published as: NZ601036A; AU2012203895A1

Abstract

A barbeque control system including a controller and a switch operatively connected to the controller, wherein heating of a hotplate of a barbeque is enabled by the controller when the controller detects that the switch is activated for a first time period, and heating of the hotplate is disabled when the controller detects that the switch is activated for a second time period, wherein the first time period is longer than the second time period. Switch Indicator(s) Controller Mains Supply Relay Temperature sensor Hotplate

Description

P/00/011 Regulation 3.2 AUSTRALIA Patents Act 1990 ORIGINAL COMPLETE SPECIFICATION STANDARD PATENT Invention Title: "BARBEQUE CONTROL SYSTEM" The following statement is a full description of this invention, including the best method of performing it known to me/us: 1 TITLE BARBEQUE CONTROL SYSTEM FIELD OF THE INVENTION 5 This invention relates generally to a barbeque control system and in particular, a control system for controlling the temperature and on/off switching of an electric barbeque. BACKGROUND OF THE INVENTION 10 Electric powered barbeques are commonly found in public parks for use by the general public, as wood fired barbeques become phased out. Electric barbeques are more user friendly, require less maintenance, are generally safer, and are more environmentally friendly. In order to switch on some prior art electric barbeques, a user presses 15 and holds down a power switch for approximately 5 seconds so that the barbeque isn't inadvertently switched on, for example by small children. The barbeque then heats up and stays on for a pre-determined period of time, after which time it switches off. The temperature of a hotplate of the barbeque is regulated to within pre-set limits by a thermostat. 20 However, a common complaint concerning electric barbeques found in public parks is that they are not hot enough to cook meat effectively. This is because the heat of the hotplate may be dissipated quickly by air currents, and the thermostat is too slow to react and switch the hotplate back on. In order to compensate, a rating of a heating element used to heat up the 25 hotplate is often increased. Another problem is that the hotplate may remain on for a period of time after the user has finished using the barbeque. This poses a danger to anyone who inadvertently touches the hotplate. A further factor to be considered is that as the barbeques are often 30 located in public places, they are more likely to be vandalised. Thus any user interface or switches must be minimal and able to resist attack from vandals. There is therefore a need for an improved barbeque control system.

2 The reference to any prior art in this specification is not, and should not be taken as, an acknowledgement or any form of suggestion that the prior art forms part of the common general knowledge in Australia or elsewhere. 5 OBJECT OF THE INVENTION It is an object, of some embodiments of the present invention, to provide consumers with improvements and advantages over the above described prior art, and/or overcome and alleviate one or more of the above 10 described disadvantages of the prior art, and/or provide a useful commercial choice. SUMMARY OF THE INVENTION In one form, although not necessarily the only or broadest form, the 15 invention resides in a barbeque control system including: a controller; and a switch operatively connected to the controller; wherein heating of a hotplate of a barbeque is enabled by the controller when 20 the controller detects that the switch is activated for a first time period, and heating of the hotplate is disabled when the controller detects that the switch is activated for a second time period, wherein the first time period is longer than the second time period. Preferably, the first time period is greater than twice a length of time of 25 the second time period. Preferably, a heating element of the hotplate is rated at 10 amperes or less. Preferably, the system further includes a temperature sensor operatively coupled with the controller for measuring a temperature of the 30 hotplate of the barbeque. Preferably, the temperature sensor is a thermocouple. Preferably, an amplifier is connected between the temperature sensor 3 and the controller. Preferably, the controller switches the hotplate off when the temperature of the hotplate reaches an upper temperature limit. Preferably, the controller switches the hotplate on when the 5 temperature of the hotplate reaches a lower temperature limit. Preferably, a temperature differential between the lower temperature limit and the upper temperature limit is 2 degrees Celsius. Preferably, the upper temperature limit is 241 degrees Celsius. Preferably, the lower temperature limit is 239 degrees Celsius. 10 Preferably, heating of the hotplate is deactivated when the hotplate is switched on for a certain period of time. Preferably, the system further includes a relay controlled by the controller for connecting a mains supply to the hotplate. Preferably, the mains supply is an alternating current (AC) voltage. 15 Preferably, the relay is an electronic relay. Preferably, the electronic relay includes a zero crossing detector. Preferably, the electronic relay connects the mains supply to the hotplate when a phase of the mains supply is substantially zero degrees. Preferably, the system includes at least one indicator connected to the 20 controller. Preferably, one of the indicators is a power indicator. Preferably, another of the indicators is a timer indicator. BRIEF DESCRIPTION OF THE DRAWINGS 25 An embodiment of the invention will be described with reference to the accompanying drawing in which: FIG 1 is a block diagram illustrating a barbeque control system according to an embodiment of the present invention. 30 DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT Elements of the invention are illustrated in concise outline form in the drawings, showing only those specific details that are necessary to 4 understanding the embodiments of the present invention, but so as not to clutter the disclosure with excessive detail that will be obvious to those of ordinary skill in the art in light of the present description. In this patent specification, adjectives such as first and second, left 5 and right, front and back, top and bottom, etc., are used solely to define one element from another element without necessarily requiring a specific relative position or sequence that is described by the adjectives. Words such as "comprises" or "includes" are not used to define an exclusive set of elements or method steps. Rather, such words merely define a minimum set 10 of elements or method steps included in a particular embodiment of the present invention. It will be appreciated that the invention may be implemented in a variety of ways, and that this description is given by way of example only. The barbeque control system is connected to a hotplate of a 15 barbeque. The hotplate includes a heating element that transfers heat to the hotplate, as would be understood by a person skilled in the art. Heating of the hotplate is enabled by a controller when the controller detects that a switch is activated for a first time period, and heating of the hotplate is disabled when the controller detects that the switch is activated for a second 20 time period, wherein the first time period is longer than the second time period. Once enabled, the controller keeps a temperature of the hotplate to within pre-defined temperature limits. The temperature of the hotplate is monitored by a temperature sensor connected to the controller. The controller switches the hotplate on when the 25 temperature is at or below a lower limit and switches the hotplate off when the temperature is above an upper limit. Furthermore, the controller disables the hotplate when the hotplate has been enabled for a preset period of time. An advantage of this arrangement is that the hotplate may be switched off by the user when he or she has finished using the barbeque, 30 thus saving energy. Disabling the hotplate allows the hotplate to cool down more quickly, thus minimising the risk of someone being burned by unintentionally touching the hotplate. In addition, the barbeque is less likely 5 to be switched on inadvertently, as the switch needs to be held for a relatively long period of time, indicating that the user has the intention of using the barbeque. FIG 1 is a block diagram illustrating a barbeque control system 10 5 according to an embodiment of the present invention. The system 10 includes a controller 20, a temperature sensor 30, a relay 40, a switch 50 and one or more indicators 60. The temperature sensor 30, the relay 40, the switch 50 and the indicators 60 are connected to the controller 20. The relay 40 is also connected between a mains supply 80 and a hotplate 70 of a 10 barbeque. In one embodiment, the mains supply 80 supplies a mains voltage such as 240Vac. However it should be appreciated that the system 10 may be used with any suitable mains voltage, depending on the country of use. Furthermore, it should be appreciated that the mains supply 80 may supply a DC voltage. 15 The controller 20 is any suitable microprocessor or microcontroller. The controller 20 is powered from the mains supply 80 via a suitable power supply (not shown). The controller 20 enables heating of the hotplate 70 when the switch 50 is activated for more than a first time period, for example 10 seconds. However it should be appreciated that the first time period may 20 be any suitable length of time. The controller 20 disables heating of the hotplate 70 when the switch 50 is activated for more than a second time period, for example 2 seconds, but less than the first time period. Once heating of the hotplate 70 has been enabled, the controller 20 regulates the temperature of the hotplate 70 by connecting or disconnecting 25 the mains supply 80 to a heating element of the hotplate 70 via the relay 40, hence switching the hotplate 70 on and off respectively. In one embodiment, the hotplate 70 is switched off when the temperature reaches an upper temperature limit of 241 degrees Celsius or greater, and the hotplate 70 is switched on when the temperature falls to a lower temperature limit of 239 30 degrees Celsius or less. Thus a temperature differential of 2 degrees Celsius. However it should be appreciated that the controller 20 may be programmed to regulate the temperature of the hotplate 70 to within any 6 suitable temperature differential. In addition, the controller 20 includes a timer to deactivate heating of the hotplate 70 when the hotplate 70 has been activated or switched on for a certain period of time, for example 30 minutes. However it should be 5 appreciated that the controller 20 may be programmed for any period of time. The temperature sensor 30 may be any suitable temperature sensor 30. Some examples of temperature sensor 30 include a thermocouple, a thermistor and a Resistance Temperature Detector (RTD). As previously mentioned, the temperature sensor 30 is installed on the hotplate 70 of a 10 barbeque. The controller 20 monitors a voltage at an output of the temperature sensor 30 which corresponds with a temperature of the hotplate 70. As the voltage from the temperature sensor 30 is small, an amplifier (not shown) may be connected between the controller 20 and the temperature sensor 30. 15 The relay 40 is controlled by the controller 20 and switches the hotplate 70 on and off by connecting the hotplate 70 to the mains supply 80 in response to a control signal from the controller 20. In one embodiment, the relay 40 is an electronic relay. However it should be appreciated that any suitable mechanical relay or electronically controlled switch may be used 20 such as a Silicon Controlled Rectifier (SCR) or a thyristor. In one embodiment, the relay 40 includes a zero crossing detector to connect the mains supply 80 to the hotplate 70 when a phase of the mains supply 80 crosses zero degrees. The zero crossing detector reduces a power surge when the mains supply 80 is first connected to the hotplate 70. 25 The switch 50 is any suitable switch that requires an action of the user, such as pressing and holding a button, in order to activate it. The controller 20 monitors an output from the switch 50. As previously described, when the switch 50 is activated for 10 seconds or more, the controller 20 enables heating of the hotplate 70. When the switch 50 is activated for 2 30 seconds or more, but less than 10 seconds, the controller 20 disables heating of the hotplate 70. The indicators 60 are any suitable light, LED or any other visual or 7 audible indicators. In one embodiment, the indicators 60 are a power indicator to indicate when the controller 20 is powered, and a timer indicator to indicate when heating of the hotplate 70 is enabled. As the temperature of the hotplate 70 is more tightly controlled, a 5 lower rated heating element (not shown) may be used to heat the hotplate 70. In one embodiment, the heating element is rated at 10 Amperes or less. Typically, prior art barbeques utilise heating elements that are rated at 13 Amperes or more in order to heat up the hotplate 70 more quickly. In use, a user presses the switch 50 for 10 seconds in order to heat 10 the hotplate 70 of the barbeque to a stable temperature that is less susceptible to windy conditions. Once the user has finished cooking on the barbeque, the user presses the switch 50 for at least 2 seconds (but less than 10 seconds) to switch off the barbeque and allow the hotplate 70 to cool. If the user does not manually switch off the barbeque, the barbeque 15 switches off after 30 minutes. In summary, some advantages of a system of the present invention include: 1) The system can be switched on and off using a single switch and is thus less susceptible to vandalism; 20 2) Heating of the hotplate is less likely to be inadvertently activated; 3) The temperature of the hotplate is more tightly controlled, and is faster to react than prior art barbeques, thus increasing heating efficiency. This means that the temperature of the hotplate is less likely to cool down even on a windy day, allowing food to be cooked more quickly; 25 4) Due to the increase in heating efficiency, a lower rated heating element may be used when compared with prior art barbeques, thus reducing the cost of electricity; 5) The barbeque can be manually turned off when the user has finished cooking, thus saving energy and making the barbeque safer; and 30 6) The system 10 may be designed into systems having a low hotplate for use by disabled persons, due to the increased safety features of ease of use, and controlling on/off switching of the barbeque.

8 The above description of various embodiments of the present invention is provided for purposes of description to one of ordinary skill in the related art. It is not intended to be exhaustive or to limit the invention to a single disclosed embodiment. As mentioned above, numerous alternatives 5 and variations to the present invention will be apparent to those skilled in the art of the above teaching. Accordingly, while some alternative embodiments have been discussed specifically, other embodiments will be apparent or relatively easily developed by those of ordinary skill in the art. Accordingly, this patent specification is intended to embrace all alternatives, modifications 10 and variations of the present invention that have been discussed herein, and other embodiments that fall within the spirit and scope of the above described invention.

Claims

1. A barbeque control system including: a heating element; a controller operatively connected to the heating element; and a switch operatively connected to the controller; wherein heating of the heating element is enabled by the controller when the controller detects that the switch is activated for a first time period, and heating of the heating element is disabled when the controller detects that the switch is activated for a second time period, wherein the first time period is longer than the second time period.

2. The barbeque control system of claim 1 wherein the first time period is greater than twice a length of time of the second time period.

3. The barbeque control system of claim 1 or claim 2 wherein the heating element is rated at 10 amperes or less.

4. The barbeque control system of any preceding claim wherein the system further includes a temperature sensor operatively coupled with the controller for measuring a temperature of a hotplate of the barbeque.

5. The barbeque control system of claim 4 wherein the temperature sensor is a thermocouple.

6. The barbeque control system of claim 5 wherein an amplifier is connected between the temperature sensor and the controller.

7. The barbeque control system of claim 4 wherein the controller 10 switches the heating element off when the temperature of the hotplate reaches an upper temperature limit.

8. The barbeque control system of claim 4 wherein the controller switches the heating element on when the temperature of the hotplate reaches a lower temperature limit.

9. The barbeque control system of claim 7 and claim 8 wherein a temperature differential between the lower temperature limit and the upper temperature limit is 2 degrees Celsius.

10. The barbeque control system of claim 9 wherein the upper temperature limit is 241 degrees Celsius.

11. The barbeque control system of claim 9 wherein the lower temperature limit is 239 degrees Celsius.

12. The barbeque control system of any preceding claim wherein the heating element is deactivated after the heating element is switched on for a certain period of time.

13. The barbeque control system of any preceding claim wherein the system further includes a relay controlled by the controller for connecting a mains supply to the heating element.

14. The barbeque control system of claim 13 wherein the mains supply is an alternating current (AC) voltage.

15. The barbeque control system of claim 13 wherein the relay is an electronic relay. 11

16. The barbeque control system of claim 15 wherein the electronic relay includes a zero crossing detector.

17. The barbeque control system of claim 15 wherein the electronic relay connects the mains supply to the heating element when a phase of the mains supply is substantially zero degrees.

18. The barbeque control system of any preceding claim wherein the system includes at least one indicator connected to the controller.

19. The barbeque control system of claim 18 wherein one of the indicators is a power indicator.

20. The barbeque control system of claim 18 wherein one of the indicators is a timer indicator.