AU2004218710A1 - Water Saving Pump Timer - Google Patents

Description

Water Saving Pump Timer O Field of the Invention This invention relates to timers and more particularly to a mechanism for detecting when a water pump is operating and controlling the flow _therefrom in accordance with a user defined or default maximum duration.

00 SBackground of the Invention 10 It is not uncommon for a water system to fail. Equipment failure or Sneglect may result in both water wastage or water damage to surroundings. It would be desirable to automatically limit the supply of flowing pump-supplied water to a maximum duration or to automatically alert a user that a set duration of pump flow has been arrived at.

Summary of the Invention It is an object of this invention to provide a device for overcoming the above problems by providing an automatic water cut off mechanism that operates to limit water flow, or generate an alarm, or both once a predetermined duration or time limit of uninterrupted pump flow has passed.

The device comprises an electronic timer and a current sensor. The timer is started by sensing an electrical loading of a pump. A microprocessor responds to the current sensor and controls the duration of power supplied to the pump to limit the duration that the pump may operate without interruption.

In some embodiments the microprocessor also controls one or more alarms.

In other embodiments the device comprises a timer and a current, pressure or flow sensor or transducer. The timer is started by (indirectly) sensing a pressure drop etc. in the water supply line. A microprocessor responds to a signal from the transducer, this signal resulting from the pressure drop or flow etc. in the water supply line which in turn starts the pump. The timer regulates the flow in the supply line to limit the duration of uninterrupted flow.

Brief Description of the Drawing Figures

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0 Figure 1 is a schematic diagram illustrating the implementation of a device made in accordance with the teachings of the present invention; Figure 2 is a plan view of a device fabricated for implementing the principles of the invention; Figure 3 is an illustration of a control panel of the device of Figure 2; Figure 4 is a flow chart illustrating the operational sequence of a device of the type depicted in Figures 2 and 3; Figure 5 is a flow chart illustrating the set-up mode of a device of the type depicted in Figures 2 and 3; Figure 6 is a flow chart illustrating the self-test function of a device of the type depicted in Figures 2 and 3; and Figure 7 is a circuit diagram for a device of the type depicted in Figures 2 and 3.

Best Mode and Other Embodiments Overview In summary, the device lo limits how long an electrical water pump can operate continuously. The device detects the beginning of the pump's operation and applies a user determined or default time limit. When the limit of continuous operation is reached, the device stops transmitting power to the pump and the pump stops operating until it is reset by a user. Accessory solenoid valves and alarms may be triggered by the device.

As shown in Figure i, a pump timer lo fabricated in accordance with the teachings of the present invention saves water by controlling the flow of water from a source or reservoir 11 through to one or more devices. Devices such as taps, washing machines, irrigation equipment etc. that consume or discharge water are represented in this illustration as a single tap operated faucet 12. In this example, the reservoir 11 may be a dam, or holding tank. As will be explained, the tank 11 may be above ground or below ground. The tank or reservoir 11 delivers its contents to a feed line 13. The feed line 13 may incorporate a manually operated valve 14 and, if required, a solenoid operated O valve 15 driven by the timer device lo.

S 5 The feed line 13 leads to a pump 16 that is driven by an electrical motor 17. The pump 16 delivers its output 18 as a supply of flowing water. The timer 1o of the present invention is operated from a source of electrical power 19 such as a 24oV outlet. The timer 10 supplies electrical power through a lead 00 20 to the electrical motor 17. The timer lO is also capable of regulating the S 10 primary solenoid valve 15, as will be explained. The timer lo is also capable of generating local (built-in) or remote alarms in response to alarm signals that the timer's microprocessor generates. Alarm signals can be used to generate audible or visual alarms located within the timer's own enclosure or to a remote alarm 21, as illustrated.

Enclosure and Control Panel Design As shown in Figure 2, the timer lo of the present invention is contained within an enclosure 22. The enclosure 22 is characterised by, for example, a lead 19 for plugging the device into 240V mains power as well as a power socket 24 on a lead 20, from which an electrical pump may be monitored, supplied with power and regulated. The enclosure 22 also features optional output sockets 25, 25a from which a remote alarm or a solenoid etc. can be operated.

As shown in Figure 3, the enclosure 22 further incorporates a display and control panel. The control panel features LEDs for indicating: when the unit is supplied with power 30, when the remote solenoid drive is on 31 and when the electrical pump is on 32. A separate LED 33 indicates when the timer has been tripped, indicating that the pump has been switched off. A reset button 34 serves as a user input for restoring power to the pump as well as an input device for programming the unit, as will be explained.

Operation Sequence As shown in Figure 4, the unit begins in a "normal" mode which is O indicated by the illumination of a green) "power on" LED 30. From this normal mode 40, the electrical pump 17 will begin its normal operation when water is called for, for example, from the tap 12. After the pump starts 41 the _timer device io senses the electrical load demanded by the pump 17. When the load is sensed, a blue) LED 32 is illuminated. Where an external 00 solenoid 15 is also controlled by the timer io the solenoid is switched on 43 S 10 that also causes a yellow) LED 31 on the control panel to be illuminated.

As the timer lo first senses the load 42 imposed by the pump 17 a timing circuit within the device starts 44. As will be explained, the timing circuit is optionally programmable by the user to create an automatic limit to the duration of continuous pump operation which is deemed acceptable by the user.

A microprocessor within the timer io determines the duration of the continuous load imposed by the pump 17. The microprocessor determines whether the user's programmed duration has been reached or not. If the duration has not been reached, the unit continues to operate in normal operation mode 40. Where the temporal duration reached, the timing circuit times out 46. This causes the red LED 33 to become illuminated and may also trigger one or more internal or external alarms. Internal or external alarms may be visual or audible, as will be explained. When the timing circuit causes an interruption in the pump's power supply, the pump stops operating 47 and the external solenoid 15, if present, closes a supply valve. When the solenoid closes, thereby interrupting the water supply, the blue LED 31 turns off and the unit enters a safe mode 48 in which it waits for the user to operate the reset button 34.

Set-up Mode As previously mentioned, the user is able to pre-set a duration of continuous pump operation which is considered acceptable. A default duration is set if no user input is received. If the pump were to operate beyond this pre-set duration, it would be indicative that there is a fault in the water supply system and that water is potentially being wasted.

Accordingly, and with reference to Figure 5, a set-up mode is entered O into with the user plugging in the power cord 19, 23 of the device, thus applying power with the resent button 34 pressed and held in. This step 51 is successfully completed and indicated to the user with a delivery of an audible _alarm, for example, three short beeps which indicate that the set-up mode has been entered into. In this mode, it is preferred that the pump be plugged into the controller but that all of the potential sources of water supply such as taps 10 be turned off so that there is no water flow through the system.

After successfully entering the set-up mode 51, the user releases the reset button 34. This triggers the units microprocessor to deliver a five second opportunity window 53 in which to enter a selected duration. The microprocessor detects 55 whether or not the reset button 34 has been pressed within the five second opportunity window 53. If the reset button 34 has not been pressed, the microprocessor loads a default time 56, for example, minutes. Subsequently, the default time delay is loaded 57 and acknowledged with, for example, an audible signal such as a short beep for each minute entered.

Where the reset button 34 has been pressed within the 5 second opportunity window 55, the user is then permitted to press the reset button 34 once for each minute of time delay required 58. It is preferred that the unit deliver both audible and visual feed back, for example a short beep on each relay button release in addition to one or more LED flashes. The microprocessor will wait 59 for present interval such as a five second interval after entering the last relay button pressed. The five second delay or pause will then cause the microprocessor to enter and load the time delay entered by the user 6o and preferably provide feedback in the form of short beeps, one for each minute entered by the user.

In preferred embodiments, once duration is successfully entered, loaded and acknowledged, the timer io will enter a self-test mode 61 before entering the normal mode of operation 62.

Self-Test Mode As shown in Figure 6, the device o10 exits from the set-up mode 63 and O subsequently uses its microprocessor to measure the pump's nominal 5 electrical loading (current demand) without the pump 17 running 64. This measured load becomes a threshold level. The microprocessor adds the _electrical noise level to the measured current to determine a trip point 65. In 0 preferred embodiments, the blue LED 32 flashes to indicate that the trip point Shas been successfully determined. In some embodiments, the load current S 10 value is indicated 66 by the number of flashes delivered by the LED in Sresponse to signals provided by the microprocessor.

The microprocessor then enters a five second delay period 67 after which it determines 68 whether or not the pump 17 is running. If the pump is not running the unit returns to normal operation mode 69. If the pump is running, the timing circuit begins its cycle of operation 70. If the timing circuit does not reach its pre-set duration, the unit returns to the normal mode. If the timing circuit does reach its limit, the pump stops and the solenoid turns off, as previously discussed 71. When this occurs, the unit waits for a user to reset it 72.

Exemplary Circuit Diagram It will be appreciated that the objectives of the invention and the functionality of the device previously described may be achieved utilising a number of relatively conventional circuit configurations. An example of a circuit for achieving the aforesaid functionality is depicted in Figure 7.

As shown in Figure 7, 24V/5oHz power from input spades 73) is delivered to a mains transformer 74 that supplies 24 Volt 50 Hz which is used to drive the solenoid and also to a bridge rectifier sub-circuit 75. Successful operation of the bridge rectifier 75 is indicated with the (green) "power on" LED 76. The bridge rectifier circuit 75 provides a low voltage output 77 which can be used for external alarms, it also supplies /power to a switch mode power supply (SMPS) 78. The switch mode power supplies a five volt output 79 which is used internally of the device. The circuit includes power output cable and socket to which the external pump is eventually connected. A current transducer 81 senses the load imposed by the pump 17 and delivers a signal to the microprocessor in response to the presence of the load. A relay 82 O disconnects the mains power to the pump in response to control signals delivered from the microprocessor 83. An LED indicator 84 notifies the user that the supply to the external pump has been discontinued. The user input button 34 serves to both reset the microprocessor and to provide a means of allowing the user to vary the maximum duration of the pre-set interval. A 00 Stransistor 86 which is also controlled by the microprocessor 83 provides an open collector output 85 for switching external alarms, etc.

Where an external solenoid is used to control the water flow of an above ground tank, power output connector is provided. A semiconductor switch (triac) 88 is used to turn the 24 volt AC power on and off to the solenoid. An opto-coupler 89 electrically isolates the triac semiconductor switch from the microprocessor 83. A (yellow) LED go indicates when power is being delivered to the external solenoid. Pump running is indicated with a (blue) LED 91 that is operated directly from the microprocessor 83.

While the present invention has been disclosed with reference to particular details of construction, these should be understood has having been provided by way of example and not as limitations to the scope of the invention as it is expressed in the claims.

Claims (19)

1. A pump timer comprising: O an enclosure in which is located an electrical output for supplying power to a device such as a pump; a current transducer that senses the electrical load on the output and delivers a signal that indicates that a load is present; Sa microprocessor that receives the signal and comprises a timer that determines if the load is present for a pre-established continuous duration; the microprocessor regulating a first relay that disables the output when the duration has been reached.

2. The timer of claim 1, wherein: the duration is a default duration.

3. The timer of claim 1, wherein the duration is set by a user.

4. The timer of claim 1, wherein: the microprocessor operates a second relay that regulates power that is supplied to an auxiliary device.

The timer of claim 4, further comprising: an external solenoid that is disabled by the second relay when the first relay is disabled.

6. The timer of claim 4, further comprising: an external alarm that is activated by the second relay when the first relay is disabled.

7. The timer of claim 1, wherein: the enclosure further comprises output sockets for receiving electrical connections to an external alarm and an external solenoid.

8. The timer of claim i, wherein: the timer further comprises a reset button that is used to both restore power to the output and programme the microprocessor by allowing a user to input the continuos duration. 0

9. The timer of claim 1, wherein: the transducer and microprocessor cooperate to allow a user to measure a nominal pump load and electrical noise so that a load trip point can be stored by the microprocessor and uses as a threshold valve.

10. The timer of claim 5, wherein: the second relay is isolated from the microprocessor by an opto- coupler.

11. A pump timer comprising: an enclosure in which is located an electrical output for supplying power to a device such as a pump; a transducer that senses the operation of the pump, directly or indirectly, and delivers a signal that indicates that the pump is operating; a microprocessor that receives the signal and comprises a timer that determines if the operation of the pump has occurred over a pre-established continuous duration; the microprocessor regulating a first relay that disables the output when the duration has been reached.

12. The timer of claim 11, wherein: the duration is a default duration.

13. The timer of claim 11, wherein the duration is set by a user.

14. The timer of claim 11, wherein: the microprocessor operates a second relay that regulates power that is supplied to an auxiliary device.

The timer of claim 14, further comprising: an external solenoid that is disabled by the second relay when the first Srelay is disabled. 0

16. The timer of claim 14, further comprising: an external alarm that is activated by the second relay when the first relay is disabled.

17. The timer of claim 11, wherein: the enclosure further comprises output sockets for receiving electrical connections to an external alarm and an external solenoid.

18. The timer of claim 11, wherein: the timer further comprises a reset button that is used to both restore power to the output and programme the microprocessor by allowing a user to input the continuos duration.

19. The timer of claim 11, wherein: the transducer and microprocessor cooperate to allow a user to measure a nominal pump load and electrical noise so that a load trip point can be stored by the microprocessor and uses as a threshold valve. The timer of claim 15, wherein: the second relay is isolated from the microprocessor by an opto- coupler.