# Patent

## Title
Plastic inlet appliance water valve

## Abstract

To guarantee a higher reliability of operation, the capacity of a battery to reliably open and close a water valve and to operate a microprocessor is continuously checked. To do so, a plurality of reference voltages are formed. The current voltage of the battery is compared with these reference voltages, and the state of the battery is indicated on the basis of this comparison with, e.g., an LED.

## Background
The present invention pertains to a process and device for monitoring the power available to a valve in a plumbing unit, and in particular the present invention relates to a process and device where operation of a plumbing unit is adapted to the available power.

Processes and devices for the contactess electronic control of the flow of water in washing units have been known from, e.g., CH-A-651 143, CH-A-646 766 and DE-A 39 20 581. If these devices are operated from a battery, the battery in time must be replaced upon reaching a certain residual capacity. To indicate that a battery change is due, it was previously determined whether the battery voltage exceeded a predetermined voltage value. An insufficient voltage was indicated by means of an LED.

The object of the present invention is to provide a process and a device of the class described, which guarantee a higher reliability of operation and more efficient operation.

The present invention has an electrically operated valve and a control circuit means for opening and closing the valve in response to sensory inputs. A power supply, usually a battery, is used to energize the control circuit and the valve. The minimum power required to open and close the valve, as well as the minimum power needed to operate the control circuit means is determined. Since the power supply is usually a battery, the power reserve of the battery can be determined by the voltage of the battery. The power requirements of the valve and control circuit can also be equated with a voltage level of the battery.

When the voltage level of the battery is below the minimum voltage required to open the valve plus a safety factor of usually 10%, with respect to the minimum opening voltage, the present invention indicates a low battery state. The voltage of the battery is checked at substantially regular intervals, and also when the control means is opening or closing the valve. The voltage when the valve is opening and closing, is known as the loaded voltage, and the battery voltage measured otherwise is known as the unloaded voltage.

In particular, the present invention prevents the water valve from being able to be actuated and opened without being able to be closed any more at an insufficient battery or power supply voltage. The microprocessor or control means can also be prevented from assuming an uncontrolled state.

Another advantage is considered to be the fact that the battery capacity can be used up to a guaranteed minimum valve-closing voltage. The useful life of a battery is thus extended, without the risk of an increased number of malfunctions.

The various features of novelty which characterize the invention are pointed out with particularity in the claims annexed to and forming a part of this disclosure. For a better understanding of the invention, its operating advantages and specific objects attained by its uses, reference is made to the accompanying drawings and descriptive matter in which preferred embodiments of the invention are illustrated.

In the drawings:

FIG. 1 is a cross-sectional view of a water flow device with contactless electronic control.

The contactless electronic control is arranged, e.g., on a water outlet of a wash basin 12. For example, an infrared light scanner and receiver 3 is used to control the water valve 5. When, e.g., a hand is introduced into the area scanned by the infrared light scanner, the latter responds and sends a signal, which is amplified and causes the water valve to open or close. A microprocessor 7 is provided for the control, and a battery 6 is provided for power supply. An indicator 27 visible from the outside, e.g., an LED, which indicates the state of the battery 6, is provided as well.

The water valve 5 used is preferably a pulse servo valve, in which certain minimum limit values of the battery or power supply voltage can be set for reliable opening and closing. It should be borne in mind that, as a consequence of the unavoidable internal resistance of the battery, these limit values must be present and measured in the loaded state of the battery, i.e., at the end of the control pulse. The minimum closing voltage should be lower than the minimum opening voltage, so that it will always be possible after opening the valve to close the valve again with the same battery voltage.

To evaluate the state of the battery 6 or its ability to reliably open and close the valve and to reliably operate the microprocessor, three reference voltages are formed in the microprocessor.

The first reference voltage V(1) corresponds to a battery voltage which corresponds to a capacity reserve or safety factor of still approx. 10% relative to the guaranteed minimum valve-opening voltage. The second reference voltage V(0) corresponds to the guaranteed minimum valve-closing voltage. The third reference voltage V(P) corresponds to the minimum battery voltage at which the microprocessor is still able to operate. V(P) is lower than V(0), and V(0) is, in turn, lower than V(1).

The residual capacity of a lithium battery 2CR5 can be approximately determined from its discharge curve, namely, the declining curve describing the battery voltage over the discharge time. This means that, e.g., a certain residual battery capacity can be associated with a residual capacity of 10% or complete discharge.

By comparing the current battery voltage in the loaded state or in the valve-loaded state with the above-mentioned reference voltages, the electronic unit assigns the current state of the battery to one of the following states: Test new battery     Initialization Battery O.K.         State B0 Battery reserve 10%, under load State B1 Battery reserve 10%, not loaded State B2 Battery reserve 0%, under load State B3 Minimal voltage for microprocessor Shut-off of system B4 ______________________________________

The different states are displayed by the indicator, e.g., as follows: Initialization     LED flashing Battery state 0    LED off Battery state 1    LED flashing Battery state 2    LED flashing Battery state 3    LED on continuously System shut off    LED on continuously. ______________________________________

The circumstances under which the different states can be entered and left are described in the following description of the function.

After inserting fie battery, the battery is tested to determined whether the no-load battery voltage is higher or lower than V(1).

If it is higher, initialization is started. The LED indicator flashes during the initialization.

If the no-load battery voltage is lower than V(1), an attempt was made to insert an already used battery. Starting the initialization is refused in this case, i.e., the LED indicator shows continuous light (if the battery is still able to energize the LED indicator).

State B0

This state means that the battery is OK. The LED indicator remains off.

The no-load battery voltage is measured at short time intervals, i.e., every second If it is determined that the battery voltage is higher than V(1), state B0 is set; otherwise, B2 (no load) is set.

The battery voltage under load is measured each time the valve is opened (measurement of the battery voltage at the end of the switch-on pulse!). If it is determined that the battery voltage is higher than V(1), state B0 is set; otherwise, B1 (load) is set.

State B1

This state means that the battery voltage under load corresponds to a battery reserve of less than 10% with respect to the minimum voltage necessary to switch on the valve. The battery should be replaced within the next 2 to 3 weeks.

This battery change, which has become necessary, is continuously indicated by an LED indicator flashing at a frequency of, e.g., 1 Hz.

The battery voltage under load is measured each time the valve is switched on, and it is compared with V(0). If this comparison shows a value lower than V(0), a switchover to stage B3 is performed.

If the battery is not replaced within the 2 to 3 weeks mentioned, it may happen that the system remains in state B1 even longer and continues to function. However, the valve must be expected to cease opening beginning from a certain point in time, even though the electronic unit is still energized!

Reason: The voltage may drop below the minimum switch-on voltage applicable to the valve in question before the minimum closing voltage V(0) guaranteed for all valves is reached.

The advantage of this method is that the battery capacity can be utilized up to the guaranteed minimum valve-closing voltage.

State B2

In an electronic wash basin not used for a relatively long lime, the battery might be discharged to the extent that valve actuation is no longer ensured. To cover this case, the no-load battery voltage is also measured at least once per second. If a value lower than V(1) is determined, a switchover to this state B2 is performed.

State B2 differs from state B1 only in that a closing pulse is sent to the valve before the valve is switched on next. The battery voltage under load, which is determined during the closing pulse and compared with V(1) and V(0), determines whether the valve may be switched on and changed over into the state B0 or B1, or whether a changeover directly into state B3 must be performed.

State B3

This state means that the battery voltage under load is no longer sufficient with certainty for closing the valve. The system therefore refuses to switch on the valve in this state, and this refusal is made visible to the user with continuous lighting of the LED indicator.

Yet, each time the wash basin is "used," a check is performed with a closing pulse on the valve to determine whether the available battery voltage under load might still be sufficient for switching the valve off. Blocking of the system, which might otherwise be brought about by an incorrect measurement, is thus reliably avoided.

State B4

The correct function of the microprocessor is guaranteed by the manufacturer only above a minimum operating voltage. If this instruction is ignored, the microprocessor may send any erratic output signal (e.g., a command to switch on the valve!). To avoid this, the microprocessor is switched off under this operating voltage limit value V(P).

The LED indicator is then further maintained in the state of continuous light by the hardware of the electronic module until the battery is exhausted.

While specific embodiments of the invention have been shown and described in detail to illustrate the application of the principles of the invention, it will be understood that the invention may be embodied otherwise without departing from such principles.

## Claims

1. A process for electronic control of fluid flow, the process comprising the steps of: response to sensory input; circuit means; energize said valve and said control circuit means.

2. A process in accordance with claim 1, wherein unloaded power supply voltage of said power supply in a loaded and unloaded state respectively; reference voltages to determine a power capacity of said power supply.

3. A process in accordance with claim 2, wherein voltage V(1) substantially equal to a minimum voltage required to open said valve plus a safety factor; voltage V(0) substantially equal to a minimum voltage required to close said valve; in a form of reference voltage V(P) substantially equal to a minimum voltage at which said control circuit means is still able to operate.

4. A process in accordance with claim 3, further comprising: greater than V(1); and greater than V(0); V(1) and said loaded power supply voltage is greater than V(0); V(0); V(P).

5. A process in accordance with claim 4, further comprising: light.

6. A process in accordance with claim 1, further comprising: said battery, said discharge curve describing battery voltage as a function of discharge time;

7. A process in accordance with claim 3, further comprising: initialization and continuing said initialization if said power supply voltage is greater than V(1), and not continuing said initialization if said power supply voltage is less than V(1).

8. A process in accordance with claim 4, further comprising: entering said B2 state otherwise.

9. A process in accordance with claim 8, further comprising: entering said B1 state otherwise.

10. A process in accordance with claim 4, wherein: determined, and when a battery voltage under load corresponds, with respect to the minimum voltage necessary for switching on the valve, to a battery reserve that is lower than a predetermined battery reserve.

11. A process in accordance with claim 4, further comprising: valve in response to said sensory input, generating a continuous light signal, sending a closing pulse to said valve when said sensory input indicates to open said valve, measuring said loaded voltage during said closing pulse to determine whether said ability of said power supply is sufficient for closing said valve.

12. A process in accordance with claim 1, further comprising: said valve immediately before an opening of said valve, said testing only being performed when a voltage of the power supply is below a predetermined value; loaded voltages is less than V(P).

13. A device for electronic control of fluid flow, the device comprising: sensory input; energize said valve and said control circuit means to open and close said valve, said indicating means testing said power by sending and measuring a closing pulse to said valve before an opening of said valve.

14. A device in accordance with claim 13, wherein: predetermined value; residual battery reserve, predetermined residual battery reserve,

15. A device in accordance with claim 14, wherein said states are indicated by a light flashing at different frequencies.

16. A process for electronic control of fluid flow, the process comprising the steps of: response to sensory input; voltage required to open said valve plus a safety factor; voltage required to close said valve; voltage required to properly operate said control circuit means; applying of power is greater than V(1) and entering a state B2 when said unloaded power supply voltage is less than V(1); voltage of said power supply and remaining in said B0 state if said unloaded power supply voltage is greater than V(1) and entering said state B2 when said unloaded power supply voltage is less than V(1); control circuit means one of opens and closes said valve, and remaining in said B0 state if said loaded voltage is greater than V(1) and entering a state B1 when said loaded voltage is less than V(1); said control circuit means opens said valve, and remaining in said B1 state if said loaded voltage is greater than V(0) and entering a state B3 when said loaded voltage is less than V(0); input indicates to open said valve, and measuring said loaded voltage during said closing pulse, entering into said B1 state if said loaded voltage is greater than V(0) and entering said state B3 when said loaded voltage is less than V(0).

17. A process in accordance with claim 16, further comprising: valve in response to said sensory input.

18. A process in accordance with claim 16, further comprising:

19. A process in accordance with claim 16, further comprising: input indicates to open said valve and measuring said loaded voltage during said closing pulse, entering into said B1 state if said loaded voltage is greater than V(0), and remaining in said B3 state when said loaded voltage is less than V(0).

20. A process in accordance with claim 16, further comprising and de-energizing said control circuit means; valve to be greater than said minimum voltage required to close said valve.