AU2005209608A1

AU2005209608A1 - A shower timer

Info

Publication number: AU2005209608A1
Application number: AU2005209608A
Authority: AU
Inventors: Tom Coverdale; Stephen Lister
Original assignee: NELSON LAMPS AUST Pty Ltd; D&B Wholesale Pty Ltd
Current assignee: NELSON LAMPS AUST Pty Ltd; D&B Wholesale Pty Ltd
Priority date: 2004-11-04
Filing date: 2005-09-08
Publication date: 2006-05-18

Description

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AUSTRALIA

Patents Act 1990 COMPLETE SPECIFICATION STANDARD PATENT Applicants: NELSON LAMPS AUST PTY LTD D B WHOLESALE PTY LTD Invention Title: A SHOWER TIMER The following statement is a full description of this invention, including the best method of performing it known to us: 2 A SHOWER TIMER Field of the Invention 00 The present invention relates to a shower timer useable to provide an alert signal during showering to indicate that 00 a predetermined period of time has elapsed.

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Background of the Invention S In many countries, water reserves are relatively low and C1 water conservation is an ongoing concern which must be communicated to citizens so that demand for water will continue to be met by the available water supply. For some actions, such as showering, considerable water is used in a relatively short time period and significant water savings would be achieved if the showering duration could be reduced.

However, it is often difficult to encourage a reduction in water usage, in particular for actions such as showering, and especially difficult to encourage children to reduce water usage.

In the claims of this application and in the description of the invention, except where the context requires otherwise due to express language or necessary implication, the words "comprise" or variations such as "comprises" or "comprising" are used in an inclusive sense, i.e. to specify the presence of the stated features but not to preclude the presence or addition of further features in various embodiments of the invention.

Summary of the Invention In accordance with an aspect of the present invention, there is provided a shower timer comprising: H,\jnelson\keep\speci\Corpletes\P58046 A SHOWER TIMER Compl.doc 8/09/05 3 means for generating an actuation signal when sound frequencies corresponding to the sound of falling water in Sa shower are detected; oo00 alarm means for generating a perceptible alarm signal; and processing means arranged to cause the alarm means to 00 generate a perceptible alarm signal in response to NO generation of the actuation signal at a predetermined time period after generation of the actuation signal.

S SIn one arrangement, the means for generating an actuation signal comprises: a microphone for generating a microphone signal representative of sound incident on the microphone; and band pass filtering means arranged to filter the microphone signal such that a predetermined range of frequencies including frequencies substantially corresponding to the sound of falling water in a shower are passed; wherein the means for generating an actuation signal is arranged to generate a trigger signal when the average peak amplitude of the filtered signal is greater than a predetermined threshold.

In one arrangement, the band pass filtering means includes a plurality of amplification and filtering stages, for example three separate stages, each of which includes a filtering component and an amplification component.

The band pass filtering means may be arranged to pass frequencies within a range 7kHz to In one embodiment, the means for generating a trigger signal comprises an operational amplifier, an output of the band pass filtering means being connected to a noninverting input of the operational amplifier through a diode, the output of the band pass filtering means being Ht\jnelson\keep\speci\Completes\P58046 A SHOWER TIMER Compl.doc 8/09/05 4 connected to an inverting input of the operational a amplifier through a resistor, and each of the non- Sinverting and inverting inputs of the operational 00 amplifier being connected to ground through a capacitor, the arrangement being such that the output of the operational amplifier is dependent on the peak voltage of 0 the signal output by the band pass filtering means.

NO

In one arrangement, the processing means includes a counter which is arranged to commence counting on receipt of the trigger signal and to cause the alarm means to generate a perceptible alarm signal when the counter reaches a predetermined count corresponding to the predetermined time period.

The processing means may comprise a micro-controller.

In one embodiment, the alarm means includes a loudspeaker and the processing means is arranged to generate a varying signal useable to cause the loudspeaker to emit an audible alarm signal.

The processing means may further be arranged to detect when power supplied to the shower timer is low and to generate a perceptible warning when this occurs. For example, an LED may be caused to illuminate when the power supplied to the shower timer is low.

The shower timer may further include a body portion for receiving operative components of the shower timer and a hook arranged to facilitate hanging of the shower timer.

The body portion may be rectangular shaped or tear drop shaped.

In one arrangement, the body portion comprises a compartment arranged to receive a battery holder, the battery holder including electrical contacts which connect Ht\jnelson\keep\speci\Completes\PSB046 A SHOWER TIMER Compl.doc 8/09/05 o with battery terminals when a battery is received in the a battery holder, and the electrical contacts of the battery Sholder making electrical connection with electrical 00 contacts associated with operative components of the shower timer when the battery holder is received in the compartment.

00 NO The battery holder or the body portion may include a Slocking member which may be slidable, the locking member facilitating secure fixing of the battery holder relative to the body portion.

The shower timer may further include a voltage regulator arranged to generate a regulated voltage based on a voltage received from a battery.

Brief Description of the Drawings The present invention will now be described, by way of example only, with reference to the accompanying drawings, in which: Figure 1 is a diagrammatic plan view of a shower timer in accordance with an embodiment of the present invention; Figure 2 is a diagrammatic side view of the shower timer shown in Figure 1; Figure 3 is a diagrammatic perspective view of the shower timer shown in Figure 1 with a battery holder of the shower timer shown removed; Figure 4 is an alternative diagrammatic perspective view of the shower timer shown in Figure 1 with the battery holder removed; Figure 5 is a schematic circuit diagram of circuitry of the shower timer shown in Figure 1; and Figure 6 is a frequency response graph illustrating functionality of part of the circuitry shown in Figure H,\jnelson\keep\speci\Completes\P58046 A SHOWER TIMER Compl.doc 8/09/05 6 Description of an Embodiment of the Present Invention Referring to Figures 1 to 4 of the drawings, there is

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00 shown a body portion 12 for housing operative components of the shower timer 10 and a hook 14 which serves to facilitate hanging of the shower timer 10 in a shower. In 00 this example, the body portion 12 and hook 14 are formed NO of plastics material, although it will be understood that other materials may be used, the important aspect being that the body portion 12 and hook 14 are formed of a Smaterial which is resistant to water corrosion and which C( is capable of defining a sealed enclosure for receiving operative components of the shower timer 10. In this example, the body portion 17 is generally rectangular, although it will be appreciated that other shapes are envisaged, such as a tear drop.

The operative components of the shower timer 10 include circuitry 16 shown schematically in Figure The body portion 12 includes a compartment 18 for receiving a battery holder 20. The battery holder 20 is arranged to receive a battery 22 and is provided with electrical contacts 24 which contact electrical terminals of the battery 22 when the battery is disposed in the battery holder 20 and which extend through the battery holder 20 rearwardly of the battery holder 20 as shown more particularly in Figure 4. The compartment 18 and the battery holder 20 are arranged such that the battery holder 20 is slidable relative to the compartment 18 so that the battery holder 20 is easily receivable in and removeable from the compartment 18. When the battery holder 20 is received in the compartment 18, the electrical contacts 24 make electrical connection with contacts (not shown) provided in the compartment 18.

H.\jnelson\keep\speci\Completes\P58046 A SHOWER TIMER Compl.doc 8/09/05 7 The battery 22 when received in the battery holder 20 and disposed in the compartment 18 supplies power to the Scircuitry 16 shown in Figure 5. In this example, the oo00 battery 22 is of 9v type, although it will be understood that other battery types are envisaged.

00 In order to securely fix the battery holder 20 relative to

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NO the body portion 12, a locking member 26, in this example which is slidable relative to the battery holder 20, is mounted on the battery holder The circuitry 16 is arranged to generate a perceptible alarm signal, in this example an audible alarm signal, after expiration of a predetermined period of time from turning on a shower.

The circuitry 16 includes a voltage regulator 30 which serves to produce a regulated voltage, in this example of the order of 3.6v, and a buffer 32 which interfaces between the voltage regulator 30 and the remaining parts of the circuitry so that the full output voltage produced by the voltage regulator 30 is maintained across positive and negative power rails Vcc and GND respectively.

The circuitry 16 also includes a microphone 34 connected in series with a first resistor 36 to the positive power rail Vt. The voltage generated across the microphone 34 is input to an amplifier and band pass filter 38 arranged to filter the voltage across the microphone 34 such that a range of frequencies including frequencies substantially corresponding to the sound of falling water in a shower are amplified and passed to a filter output 39. In this example, the amplifier and band pass filter 38 is arranged to pass a range of frequencies between 7kHz and 20kHz, and the amplifier and band pass filter 38 is configured so as to include three amplification and filtering stages, each stage of which has a different gain and each stage of H.\jnelson\keep\speci\Comipetes\PS846 A SHOWER TIMER Compl.doc 8/09/05 8 which is arranged to filter a different frequency range.

$4 However, it will be understood that various arrangements C for carrying out amplification and filtering are possible.

00 For example, a single amplification stage and a single filtering stage may be used.

00 C The frequency response 37 of the amplifier and band pass filter 38 in the present example is shown diagrammatically in Figure 6. As can be seen, frequencies between 7 kHz 1 0 and 20kHz which correspond to frequencies associated with the sound of falling water in a shower are passed with significant gain.

The output 39 of the amplifier and band pass filter 38 is supplied to trigger generation means 40 which serves to generate a positive trigger signal when frequencies corresponding to the sound of water falling in a shower are received by the microphone 34. The output 39 is connected to a non-inverting input of an operational amplifier 41 through a diode 42, and to an inverting input of the operational amplifier 41 through a second resistor 44. The non-inverting input of the operational amplifier 41 is also connected to ground through a first capacitor 46 and a third resistor 48 connected in parallel. The inverting input of the operational amplifier 40 is connected to ground through a second capacitor The trigger generation means 40 operates such that when the average peak amplitude of the output signal produced by the amplifier and band pass filter 38 is greater than a predetermined threshold, a positive trigger signal is produced at the output of the operational amplifier 41.

In particular, when frequencies corresponding to the sound of falling water in a shower are detected by the microphone 34, a positive varying voltage on the output 39 of the amplifier and band pass filter 38 which is H,\jnelson\keep\speci\Completes\PS58046 A SHOWER TIMER Cnompl.doc 8/09/05 9 o significantly greater than the forward bias voltage of the a diode 42 will be rectified by the diode 42 and the first Scapacitor 46, and the first capacitor 46 will charge 00 rapidly through the diode 42 and discharge slowly through the third resistor 48. As a consequence, the voltage at the non-inverting input of the operational amplifier 41 0 will have a magnitude which is approximately a diode NO forward bias voltage drop less than the peak voltage at

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the output 39 of the amplifier and band pass filter 38.

V) Similarly, the output voltage 39 of the amplifier and band c pass filter 38 will cause the second capacitor 50 to charge and discharge through the second resistor 44.

However, since the second capacitor 50 is charged through the second resistor 44, the charge rate of the second capacitor 50 will be much slower than the charge rate of the first capacitor 46. As a consequence, although the voltage across the first capacitor 46 will be approximately a forward bias voltage drop less than the output voltage 39 of the amplifier and band pass filter 38, since the charge rate of the first capacitor is much faster than the charge rate of the second capacitor the voltage at the non-inverting input of the operational amplifier 41 will be greater than the voltage at the inverting input of the operational amplifier 40 when frequencies corresponding to the sound of falling water in a shower are detected by the microphone 34.

When frequencies corresponding to the sound of falling water in a shower are not detected by the microphone 34, the output voltage 39 of the amplifier and band pass filter 38 is much lower than the corresponding output voltage 39 produced when frequencies corresponding to the sound of falling water in a shower are detected by the microphone 34. As a consequence, the forward bias voltage drop of the diode 42 becomes more significant and, H,\jnelson\keep\speci\Completes\P58046 A SHOWER TIMER Compl.doc 8/09/05 C although the first capacitor 46 still charges more rapidly than the second capacitor 50, the forward bias voltage Sdrop across the diode 42 is enough to cause the voltage o0 appearing at the non-inverting input of the operational amplifier 41 to be less than the voltage appearing at the inverting input of the operational amplifier 00

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NO It will be understood, therefore, that when frequencies corresponding to the sound of falling water in a shower 1 0 are detected by the microphone 34, a positive trigger Ssignal is produced at an output 51 of the operational amplifier 40, and when frequencies corresponding to the sound of falling water in a shower are not detected by the microphone 34, a positive trigger signal is not produced at the output 51 of the operational amplifier 41.

The voltage at the output 51 of the operational amplifier 41 is supplied to processing means, in this example in the form of a micro-controller 60. The primary function of the micro-controller 60 is to generate a pulsed control signal useable by alarm means 61 to trigger generation of an audible alarm signal after a predetermined period of time has elapsed since receiving the trigger signal. For this purpose, the micro-controller may be arranged so as to operate as a counter and may include RAM type memory.

In this example, the micro-controller 60 is arranged to generate a pulsed control signal having a frequency set by a crystal 62, the crystal 62 in this example being connected to ground through fourth and fifth capacitors 64 and 66 respectively.

The pulsed control signal input to the alarm means 61 is supplied through a fourth resistor 68 to a switching device, in this example in the form of a bipolar transistor 70, the transistor 70 serving to generate a pulsed voltage of corresponding frequency to the pulsed H,\jnelson\keep\speci\Completes\P58046 A SHOWER TIMER Compl.doc 8/09/05 11 control signal across a loudspeaker 72 by generating a a pulsed current through fifth and sixth resistors 74 and 76 Srespectively.

00 The micro-controller 60 is also arranged such that when a low battery voltage is detected by seventh and eighth 00 resistors 78 and 79 respectively, a current is caused to

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INC pass through an LED 80 and a series connected ninth resistor 82. This serves to provide a visible indication [1 0 to a user that the battery 22 is producing a low voltage and should be replaced.

The micro-controller 60 is also arranged such that when the battery 22 is removed, a counter and/or memory of the micro-controller 60 is reset.

During use, in the absence of detection by the microphone 34 of frequencies corresponding to the sound of falling water in a shower, a relatively low peak voltage signal is produced by the amplifier and band pass filter 38 which causes the voltage at the inverting input of the operational amplifier 41 to be greater than the voltage at the non-inverting input of the operational amplifier 41.

This causes the trigger signal generating means 39 to not generate a trigger signal or, in other words, to generate a voltage at the output of the operational amplifier which is substantially equal to zero. As a consequence, the micro-controller 60 does not begin counting, a control signal is not supplied to the alarm means 61, and an audible alarm is not generated by the alarm means 61.

When frequencies are detected by the microphone 34 which correspond to the sound of falling water in a shower, the amplifier and band pass filter 38 generates a signal of relatively high peak voltage which causes the voltage at the non-inverting input of the operational amplifier 41 to be greater than the voltage at the inverting input of the H:\jnelson\keep\speci\Completes\P58046 A SHOWER TIMER Coml.doc 8/09/05 %n 12 ,q operational amplifier 41. This causes a positive trigger Q^ signal to be generated at the output of the trigger signal generational means 39. As a consequence, the micro- 00 controller 60 begins counting until the counter has reached a predetermined number corresponding to a predetermined time delay. When this occurs, the micro- 00 0 controller 60 supplies a control signal to the alarm means

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61 which causes the loudspeaker 70 to emit an audible Salarm signal.

S It will be appreciated that the shower timer may be used to provide an indication to a person during showering that a predetermined time period has elapsed and that the shower should be turned off in order to conserve water.

It will also be appreciated that since with the present embodiment an on/off switch is not included, it is not possible to deactivate the shower timer without removing the battery.

Modifications and variations as would be apparent to a skilled addressee are deemed to be within the scope of the present invention.

H:\jnelson\keep\speci\Completes\P58046 A SHOWER TIMER Compl.doc 8/09/05

Claims

2. A shower timer as claimed in claim 1, wherein the means for generating an actuation signal comprises a microphone for generating a microphone signal representative of sound incident on the microphone; and band pass filtering means arranged to filter the microphone signal such that a predetermined range of frequencies including frequencies substantially corresponding to the sound of falling water in a shower are passed; wherein the means for generating an actuation signal is arranged to generate a trigger signal when the average peak amplitude of the filtered signal is greater than a predetermined threshold.
3. A shower timer as claimed in claim 2, wherein the band pass filtering means includes a plurality of amplification and filtering stages, each said stage including a filtering component and an amplification component.
4. A shower timer as claimed in claim 3, wherein the band pass filtering means is arranged to pass frequencies within a range 7kHz to H,\jnelson\keep\speci\Completes\P58046 A SHOWER TIMER Compl.doc 8/09/05 14 A shower timer as claimed in any one of claims 2 to 4, wherein the means for generating a trigger signal Scomprises an operational amplifier, an output of the band 00 pass filtering means being connected to a non-inverting input of the operational amplifier through a diode, the output of the band pass filtering means being connected to 00 an inverting input of the operational amplifier through a C) NO resistor, and each of the non-inverting and inverting inputs of the operational amplifier being connected to 1 0 ground through a capacitor, the arrangement being such that the output of the operational amplifier is dependent (N on the peak voltage of the signal output by the band pass filtering means.
6. A shower timer as claimed in any one of the preceding claims, wherein the processing means includes a counter which is arranged to commence counting on receipt of the trigger signal and to cause the alarm means to generate a perceptible alarm signal when the counter reaches a predetermined count corresponding to the predetermined time period.
7. A shower timer as claimed in any one of the preceding claims, wherein the processing means comprises a micro- controller.
8. A shower timer as claimed in any one of the preceding claims, wherein the alarm means includes a loudspeaker and the processing means is arranged to generate a varying signal useable to cause the loudspeaker to emit an audible alarm signal.
9. A shower timer as claimed in any one of the preceding claims, wherein the processing means is arranged to detect when power supplied to the shower timer is low and to generate a perceptible warning when this occurs. H,\jnelson\keep\speci\Completes\P58046 A SHOWER TIMER Comnpl.doc 8/09/05 in 15 A shower timer as claimed in claim 9, further comprising an LED, the LED being caused to illuminate when the power supplied to the shower timer is low. 00
11. A shower timer as claimed in any one of the preceding claims, further comprising a body portion for receiving 00 Soperative components of the shower timer and a hook arranged to facilitate hanging of the shower timer. (N V~ 10 12. A shower timer as claimed in any one of the preceding Sclaims, further comprising a voltage regulator arranged to generate a regulated voltage based on a voltage received from a battery.
13. A shower timer substantially as hereinbefore described with reference to, and as shown in, the accompanying drawings. Dated this 8th day of September 2005 NELSON LAMPS AUST PTY LTD D B WHOLESALE PTY LTD By their Patent Attorneys GRIFFITH HACK Fellows Institute of Patent and Trade Mark Attorneys of Australia H:\jnelson\keep\speci\Completes\P58046 A SHOWER TIMER Compl.doc 8/09/05