Abstract:
An electronically controlled electro-mechanical device designed to limit a finite amount of water per flush to a tank reservoir of the common household toilet, or tank-less toilet or urinal, providing positive shutoff of water flow and anti-siphon backflow prevention. The toilet is flushed, the flush lever activates an attached tilt switch, the tilt switch actuates the countdown timer by means of electrical linkage, the countdown timer in turn activates the solenoid valve by means of electrical connection. The water enters the solenoid valve, passing through the valve and on to the float valve mounted to the toilet tank for fill up. The Countdown timer counts down from the full minutes and seconds set to 00:00 and shuts off the solenoid valve and ultimately the flow of water. The Countdown timer then resets itself to the time set in memory for the next flush operation. A float eliminator may be affixed to the toilet tank replacing the float valve, then connected to the solenoid valve. For the purpose of adjusting the volume of water per flush the Countdown timer can be programmed from 00:00 minutes and seconds to 99 minutes and 55 seconds. The average toilet will need approximately 2 minutes. It is suggested that the user flush and time his toilet prior to installation of the electro-mechanical solenoid valve unit and add five seconds to assure the proper volume of water per flush.

Description:
[0001]     I, claim priority filing date of Jan. 25, 2005 of provisional Application No. 60/646,853 
     
    
     STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT  
       [0002]     Not Applicable  
       REFERENCE TO SEQUENCE LISTING, A TABLE, OR A COMPUTER PROGRAM LISTING COMPACT DISC APPENDIX  
       [0003]     Not Applicable  
       BACKGROUND FIELD OF INVENTION  
       [0000]     Current U.S. Class: 4/415: 4/366; 137/436; 210/170; 713/322  
         [0000]     Intern&#39;l Class: EO3D 001/00; C02F 003/02; G06F 001/04  
       REFERENCES CITED  
       [0000]     U.S. Patent Documents  
         [0000]     U.S. Pat. No. 6,903,766 Jun. 7, 2005 Silverbrook, et al. . . . 348/211.4; 348/333.06; 348/207.2; 396/264  
         [0000]     U.S. Pat. No. 6,989,721 May 24, 2005 Schmidt . . . 713/322; 713/501; 713/600; 455/205; 455/502  
         [0000]     U.S. Pat. No. 6,178,569 Jan. 30, 2001 Quintana . . . 4/427; 4/406; 73/304C; 137/392; 137/558; 340/620  
         [0000]     U.S. Pat. No. 5,752,281 May 19, 1998 Conner . . . 4/427; 4/415  
         [0000]     U.S. Pat. No. 5,524,299 Jun. 11, 1996 Dalfino . . . 4/415, 4/366; 137/410  
         [0000]     U.S. Pat. No. 5,440,756 Aug. 15, 1995 Weir . . . 4/415; 137/400  
         [0000]     U.S. Pat. No. 5,185,891 Feb. 16, 1993 Rise . . . 4/324; 4/314; 4/415; 33/531; 33/567  
         [0000]     U.S. Pat. No. 5,230,104 Jul. 27, 1993 Ocampo . . . 4/415; 4/367; 4/434  
         [0000]     U.S. Pat. No. 5,031,254 Jul. 16, 1991 Rise . . . 4/324; 4/415  
         [0000]     U.S. Pat. No. 4,901,377 Feb. 20, 1990 Weir . . . 4/415; 137/400  
         [0000]     U.S. Pat. No. 4,916,762 Apr. 17, 1990 Shaw . . . 4/366; 4/415; 222/16; 222/20; 251/230  
         [0004]     “The present invention relates to the fill and flush valves of ordinary toilets with and without holding tanks or reservoirs, more specifically to improve and expand the scope and function of the toilet fill and flush valves addressing the issues of water shut off, water conservation, environmental preservation, water damage prevention, anti-siphon, back flow prevention, and to reduce water production and sewage treatment costs due to leaking toilets and urinals.” 
       DISCUSSION OF PRIOR ART  
       [0005]     Toilet systems, of the reservoir tank type generally installed in American homes, are connected to the potable water supply. The average American home has at least one of these toilets, each of which uses approximately one and one half to three and a half gallons, or more, of water per flush, depending on the age of the toilet.  
         [0006]     Generally, toilet fill valves are made with a float mechanism causing the valve to open when the toilet is flushed as the water leaves the tank and to close once the float is lifted by the water when the tank or reservoir becomes full.  
         [0007]     Typically these toilet fill valves work fairly well but have several drawbacks that lead to wasting of water, overflow, and leaks. These drawbacks result in a myriad of problems from wells running out of water, dirt being introduced into the water lines from low water levels in shallow wells, and septic system failure, to high water and sewage bills for those on public water supply and sewage systems to water damage to the floor of a bathroom, and ceilings and walls of a downstairs room to remediation of mold and mildew.  
         [0008]     To address these issues manufacturers and inventors began to develop other types of toilet fill valves such as the “Toilet Tank Water Flow Shutoff Apparatus For Preventing Leakage And Overflow, U.S. Pat. No. 5,524,299 of Dalfino, which uses tilting trays to control water level and shutoff of the water supply. Though this device can effectively cause shut off, it tends to have many external moving parts subject to mechanical failure and also uses most of the toilet tank area and servicing as well as installation require more intensive labor and increased expense.  
         [0009]     A quite different approach is taken with the Revised Automatic Water Shut Off For Stuck Open Flush Valves In Toilet Water Tanks, U.S. Pat. No. 5,440,765 of Weir, which utilizes a two cylinder system to force the float upwards to shut off the water supply should a continuous flow or wasting of water occur. Similar to the above is the Toilet Bowl Automatic Flow Shut Off and Water Saver Device, U.S. Pat. No. 4,901,377 of Weir, that accomplishes the same results with a bellows assembly that lifts the float when the tank remains empty for a period of time beyond that of normal flushing. Both of the foregoing devices utilize a large portion of the toilet tank area to the right of the flapper valve causing access to the flapper to be flanked on all sides and tends to limit service space for repairs, causing repairs to be costly and labor intensive.  
         [0010]     Addressing the issues of conservation, the Water Conserving Toilet Flush Control, U.S. Pat. No. 5,031,254 of Rise, is a device that addresses preventing the wasting of water achieved by limiting the lifting action of the flapper and restricting or preventing automatic operation of flushing. Relatively similar in operation the Water Conserving Toilet Flapper Valve Control, U.S. Pat. No. 5,185,891 of Rise, which in effect limits the height that the flapper can be lifted achieving the same results as the prior invention of Rise when the flush lever is activated. Though both Rise controls address stopping automatic function of the flapper and limiting the flappers movement they do not address wasting of water when the flapper becomes defective by means of blowout, tear or just ordinary wear of the seal, the results of which could lead to a continuous loss of water to the sewer or overflow and water damage.  
         [0011]     Fill valves designed to save water such as the Toilet Water Preservation Device U.S. Pat. No. 5,230,104 of Ocampo, tend to use the flow of wasting water redirecting it to a secondary float device that in turn lifts the primary float device. This device though it appears to be quite functional also renders much the same results as the Weir devices utilizing or cluttering tank space hindering and causing labor intensive costly service when repairing or replacing the flapper or primary float valve. The secondary float fill valve is also still subject to fail in much the same way as the primary float fill valve.  
         [0012]     Adaptations to fill valves such as the Shut-off Device For The Float Valve Assembly Of A Toilet, U.S. Pat. No. 5,752,281 of Conner, designed so that the rotation of the lever arm causes the float valve assembly to rotate to a stop position and stop the flow of water to the toilet tank in the event that the float fails to raise up for any known reason appears as an entirely different approach. While this system would effectively shut off the flow of water it is possible that with the rotating movement of the float assembly, it could eventually cause leakage and overflow from wear due to excessive movement.  
         [0013]     Most of these devices work fairly well shutting off the water, while addressing anti-siphoning of water but do not adequately address backflow prevention, wasting of water if the float fails to be elevated by the water or lack thereof, and or overflow of the bowl or a leaky gasket between tank and toilet. Recently developed toilet fill valves address one or more of these problems.  
         [0014]     One of the more recent toilet fill valves the FlowManager™ AquaOne Technologies, Inc., addresses most of these problems, incorporates the use of electronic water sensors that detect leaks and overflow. The major drawbacks of such devices are that they require regular and periodical battery maintenance and replacement as well as regular cleaning of the sensor devices that appear as necessary clutter and are actually in the way of cleaning the bowl and or the floor. Additionally, the cleaning of the sensors and the chemicals used, both cleansers and antibacterial toilet additives can cause premature failure. Although the sensor in the bowl will effectively stop overflow of the bowl or bowl in households with children who might lose a toy or otherwise plug the bowl, a floor sensor could present a problem with flushing where bath water is accidentally splashed on it or if a child accidentally misses the bowl and wets the sensor. Electronic valve systems such as the above generally utilize a normally open solenoid valve so the batteries will last a long time if the valve is not triggered shut by a sensor; however, if the valve is triggered shut in the case of a flapper leak the batteries would not last very long which would in short time lead to water running to the sewer or worse yet water damage if the bowl was plugged.  
         [0015]     Addressing the issues of toilet tank fill and flush problems and wasting of water with control devices has made significant progress in the Positive Shut-off, Metered Water Control System For Flush Tanks, U.S. Pat. No. 4,916,762, by Shaw. This device utilizes the flow of water to turn a vaned water wheel. A worm gear attached to the water wheel drives a spur gear which in turn rotates a second spur and worm gear. The worm gear of the secondary or intermediate gear assembly then engages a spur gear seated in a ratchet and cam assembly. The cam of the ratchet cam assembly controls both opening and closing of a stopper. The cam is ratcheted to the start position by a pawl connected to the flush lever of the toilet to cause the stopper to dislodge from its seat when the toilet is flushed to allow water to pass or flow, driving the water wheel, which causes the cam to turn and reseat the stopper after the desired amount of water has been metered through the system. Although this device is impressive it has the possibility of lockup of the drive system.  
         [0016]     While addressing anti-siphon ability as with the other devices heretofore mentioned this particular device also addresses backflow prevention when the stopper is reseated by water pressure, but will not stop backflow if water pressure is lost during fill up. As previously discussed above, this invention utilizes a start arm with a pawl to ratchet forward the cam to allow a predetermined volume of water by notches fixed in the cam. While this method appears to be able to work well a shortcoming to address is each toilet with a different tank capacity would need a special cam for that particular volume of water. Additionally, this ratchet cam system does not address the ability to adjust the volume of water metered so a 3.5 gallon valve will not service the 1.5 gallon tank of a newer toilet or vise versa. In other words one size does not fit all due to the arrangement of the fixed setting or position of notches in the cam and the ratcheting mechanism.  
         [0017]     Due to the fact that until the present invention no electronic timer control for metering water flow to toilets has been developed, the search for timer modules is made in unrelated fields to the effect that the Timer module for compact printer system, U.S. Pat. No. 6,903,766, of Silverbrook, et al. though it is applied to printer systems this unit can be preset to spool documents, pictures, images for printing as well as captures images by specific intervals, however it does not apply itself to the present invention&#39;s countdown timer control where the timer control is preset to be programmed by the user for specific on and off control of electronic devices such as the solenoid valve discussed below, triggered by a tilt switch.  
         [0018]     In addition to searching the Timer module for compact printer systems, I felt it necessary to search at least one other timer or clock system thus for the purpose of eliminating any infringements the Clock generation systems and methods, U.S. Pat. No. 6,898,721, of Schmidt, was searched to compare the timer controlling processor. In the clock generation systems and methods each of the processing units has a clock input to control the performance of the unit, wherein the processors are all receiving input from a common master clock via a transceiver. This unit is in effect designed to generate a clock signal to speed up performance of computerized functions and processors and thus does not relate to the present invention or it&#39;s application.  
       SUMMARY OF THE INVENTION  
       [0019]     Accordingly, the reader will see in  FIGS. 1 and 2  the instant invention, a countdown timer, and in  FIGS. 1 and 4  a solenoid safety valve, comprising a safety valve system designed to operate in conjunction with or without a float assembly by providing a limited amount of water to any given toilet during flushing sufficient to allow a complete flush and performing a positive shut off of the water supply every time a numeric display shown in  FIGS. 1 and 2  displays 00-00 even if the flushing operation should fail for any reason. Should a toilet float, flapper, or other tank-less flushing mechanism fail to operate properly and only after the maximum amount of water limited by time control has passed to the tank of a toilet, a rundle of a tank-less toilet or urinal, the electronically controlled solenoid valve of the instant invention will close and prevent the flow of water for the purpose of eliminating running or wasting of water, preventing overflow and or water damage. Additionally the valve is normally closed and doubles as a backflow prevention check valve to stop any possible reverse flow in case of water pressure loss. The volume limiting shut-off action of the present invention can be used on any common or uncommon toilet tank of any dimension, comprising a time programmable countdown timer controller shown in  FIGS. 1 and 2 , which is turned on by means of a tilt switch shown in  FIGS. 1 and 2 B, connected to said timer, by means of a tilt switch transmission wire, and a tilt switch plug.  
         [0020]     A solenoid safety valve is also connected to said timer by means of a valve power feed wire depicted in  FIGS. 1 and 2 B, by means of a valve power feed wire plug. The solenoid safety valve is positioned within the water feed line shown in  FIG. 1 , by means of two compression fittings to start and stop the flow of water from the feed line angle stop to the toilet during operation.  
         [0021]     The tilt switch is attached to the toilet flush rod shown in  FIG. 1 , by means of two wire ties, when the flush lever is depressed the tilt switch causes the countdown timer to start the preset timed event which in turn sends power to the solenoid safety valve by means of the valve power feed wire and plug connection. As said valve opens the water flows from the water feed line into the inlet of said valve through said valve and out the outlet of said valve continuing on into the toilet float valve assembly, or through a float eliminator to fill the toilet tank as normal, or directly to the rundle of a tank-less toilet or urinal.  
         [0022]     Ideally, if used the float assembly affixed to the uppermost portion of the float valve body will successfully activate shut off five seconds prior to the conclusion of the preset countdown timed closing of the solenoid valve installed in the toilet water feed line. The countdown timer will reset to its preset time and wait for the flush lever to be depressed for the next flush. Any toilet tank that has a lesser volume capacity than the capacity set by time will cause the float valve to elevate and effectively shut off the flow of water and the countdown timer will finish it&#39;s cycle anyway. It is suggested for the purpose of equal control of water flow that a user should flush the toilet and time the flush prior to installation and set the control for five seconds longer than the actual flush to eliminate excess over flush water if the toilet float or flapper fails. Should the float or flapper fail to close, the tank would call for more water than allowed, the countdown timer will shut off the valve and flow of water when the time limit is reached simultaneously the volume of water will have been reached effectively conserving water and reducing the volume of sewage waste caused by toilets that continuously run. In effect and operation the function of the instant invention is to shut off the water supply after every timed flush irregardless of any malfunction of the toilet flushing system for any reason, ultimately rendering all other sensor systems, gadgets, duel float controls, and other anti-overflow devices obsolete, while preventing overflows, flooding and excessive waste of water and generation of unnecessary sewage.  
         [0023]     The reader will note that there are two interchangeable water delivery systems for toilets with tanks, one being the common float assembly and the other being a float eliminator. When using a common float assembly the countdown timer and solenoid valve can be used universally irregardless to capacity. The second delivery system is the float eliminator. This system replaces the float valve and attaches to the toilet tank the same way as the float valve assembly. However this system is simply a channeling device that directs the water downward towards the base of the tank for fill up from a delivery tube, with a replenish tube shaft at its upper most portion for removeably connecting the replenish tube to restore the water level in the bowl during fill up. The float eliminator has been designed and described in the present inventor&#39;s prior invention the Toilet King, U.S. patent application No. 11,090,602, and needs no further discussion here.  
       OBJECTS AND ADVANTAGES  
       [0024]     Accordingly, being designed to address the problems of toilets that have been discussed with the prior art, several objects and advantages of the present invention are: 
    (a) to provide a limited supply of water by timed volume to any given flush mechanism or toilet tank per flush irregardless of a flapper or float malfunction;     (b) to provide a failsafe positive shutoff of the water feed line when the maximum limit of water by timed volume has been reached;     (c) to prevent overflow and limit the extent of water damage from a plugged toilet or sewer drain;     (d) to conserve water, and to prevent wasting of water;     (e) to reduce municipal water production and waste water treatment costs;     (f) to reduce the production of unnecessary sewage pollution into the environment;     (g) to provide a positive means of anti-siphon and backflow prevention.    
 
         [0032]     Further objects and advantages are to provide a cost-effective, easy to install toilet fill valve that will not interfere with servicing of other toilet tank parts. For instance with the present invention should the flapper valve not seat properly or worse yet rupture the water supply will be shut off and the toilet tank will be left empty and ready for easy no muss or fuss servicing. A new flapper can be installed or a leaky flapper can be adjusted without taking too much time for cleanup, and once the repair is complete all that is necessary to return to normal flushing operation is to activate the flow of water by depressing the flush lever of the toilet tank and the tank will fill up for the next flush. One could even completely remove the toilet without a water mishap simply by unplugging the valve  44 , from the countdown timer  29  as the valve is normally closed. 
     
    
     BRIEF DESCRIPTION OF SEVERAL VIEWS OF THE DRAWING  
       [0033]     The present invention will be better understood from the following detailed description as depicted in the drawings in which like reference numerals refer to like parts; closely related figures have the same number but different alphabetic suffixes.  
         [0034]      FIG. 1  is a front partial cutaway view of a typical conventional toilet tank with the tank lid removed, incorporating the Countdown Timer automatic water limiting, supply Shut off Safety Valve flo-control system of the present invention;  
         [0035]      FIG. 2  is a front view of the Countdown Timer of the present invention;  
         [0036]      FIG. 2A  is a rear view of the Countdown Timer of the present invention;  
         [0037]      FIG. 2B  is a side view of the Countdown Timer of the present invention;  
         [0038]      FIG. 3  is the Countdown Timer schematic of the present invention;  
         [0039]      FIG. 4  is a cutaway front view of the supply shut off solenoid valve of the present invention; 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0040]     The following description is provided to enable any person skilled in the art to make and use the invention and sets forth the best modes contemplated by the inventor for those so skilled to do so.  
         [0041]      FIG. 1  is a front view of a conventional toilet tank  10 , of the type universally found in most homes in the United States and North America, which is fitted with a Countdown Timer  29 , and a Solenoid Safety Valve  44 , in accordance with the present invention. In the conventional home toilet, a ball cock assembly comprising a float arm, and float ball is mounted at the upper end of a water tube for closing an inlet valve via a mechanical linkage when the tank is filled to a predetermined level. In the present invention a float valve assembly is left unchanged being mounted to the tank in its usual fashion.  
         [0042]     The illustrated toilet tank comprises a toilet tank  10  with a float valve inlet  14 , extending through the left rear bottom of the tank  10 . Water supply is introduced by means of a water feed line  16 , which is connected by known means of a standard sized fitting as currently used with flush tanks, providing a sealable mount to the tank  10 . A Solenoid Safety Valve  44 , is fitted into the water feed line  16 , by means of two compression fittings  18 . Water received in tank  10 , which exceeds the tank&#39;s design capacity spills into a standard overflow tube wherefrom it is discharged to the bowl through the main tank outlet  12 , which is normally closed by a standard flapper. When water from tank outlet  12 , is introduced into toilet bowl the level of water in bowl is raised until it exceeds the waste outlet of the flush trap causing the water to flow from bowl by siphoning action.  
         [0043]     As demonstrated in  FIG. 1  and again in  FIG. 2B , the solenoid safety valve  44 , is electronically connected to the countdown timer  29 , by means of a valve power feed plug  41 , and a valve power feed wire  42 , to open the valve  44 , during operation.  
         [0044]      FIG. 1  shows, a flush handle  19 , located in the upper left front area of the tank  10 , used to activate the flushing operation of the toilet. When depressed the flush handle lifts a flush rod  20 , lifting open the flapper by means of a flapper flush linkage  21 , simultaneously the flush rod  20 , activates a tilt switch  36 , connected to said flush rod  20  by means of two wire ties  40 . Said tilt switch  36 , is electronically connected to said countdown timer  29 , by means of a tilt switch plug  35 , connected to a tilt switch transmission wire  38 , which activates the countdown timer  29 , allowing water to flow to the tank  10 , by electronically opening the Solenoid Safety Valve  44 , for a time period set by the user sufficient to allow for a complete flush.  
         [0045]     As shown in  FIG. 1 , the countdown timer has three buttons; the first is a set button  46 , the second is a minute button  48 , and the third is a second button  50 . Although self explanatory the operation and function will be discussed a little later on.  
         [0046]     Also shown in  FIG. 1  the reader will note there is a power indicator LED  52 , a charge indicator LED  54 , and a low battery LED  56 , though easily understood, the purpose and function will be discussed a little later on.  
         [0047]     A wall transformer  32 , which is plugged into a wall outlet  22 , is connected to the countdown timer  29 , by means of a wall transformer power cord  34 , a wall transformer plug  33 , and a wall transformer plug receiver  31 , mounted solidly to a enclosure side  25  as depicted in  FIG. 2B .  
         [0048]      FIG. 2  is a front view of the countdown timer  29 , as described in  FIG. 1 . The preferred embodiment of said countdown timer  29 , is comprised of an enclosure front  24 , consisting of two equal sized numeric displays  30 , to allow the user to program and view the run time and see the running countdown when activated. The countdown timer  29 , is turned on and programmed by means of three control buttons. The control buttons consist of a set button  46 , colored red, a minute button  48 , colored green, and a second button  50 , colored yellow, located below and slightly to the left of the numeric digital display  30 . To turn on the countdown timer  29 , the operator or user will depress and hold the second button  50 , then depress the set button  46 . To set the running time for countdown the user will press the set button  46 , until the numeric displays  30 , flash 00 and 00. The user will then set the minute run time by depressing the minute button  48 , once for each minute desired and then depress the second button  50 , once for every five (5) seconds desired. Once the time has been selected the user will then depress the set button  46 , to commit the run time desired to memory.  
         [0049]     To the right and below the numeric displays  30 , the user will find three indicator LEDs, the uppermost being a power indicator LED  52 , colored red when lit to indicate that a wall transformer  32 , is connected to the countdown timer  29 . The middle being a charge indicator LED  54 , colored green when lit to allow the user to see when the countdown timer  29 , is in charge mode. The lower most being a low battery indicator LED  56 , colored yellow to allow the user to see the condition of the battery.  
         [0050]      FIG. 2A  is a rear view of the enclosure back  26 , of the same dimensions and mating the enclosure front  24 , consisting of two enclosure screws  27 , located center from side to side and in from top and bottom edges sufficient to hold said enclosure front and back securely together while accommodating the electronics within, and keeping in place two enclosure sides  25 , of the same dimensions. One side being without plug receivers, the other side being with plug receivers as depicted in  FIG. 2B .  
         [0051]     As depicted in  FIG. 2A  in the rear view of the enclosure back  26 , the reader will find a wall hanger hole  28 , for mounting to a wall with a wall anchor screw (not shown).  
         [0052]      FIG. 2B  is a side view of the countdown timer  29 , depicting the enclosure side  25 , with left and right sides being of the same dimension. The difference between the two sides is that the right enclosure side  25 , is fitted with a tilt switch plug receiver  39 , a wall transformer plug receiver  31 , and a valve power feed plug receiver  43 .  
         [0053]      FIG. 3  is the Countdown Timer schematic of the present invention as described hereafter by: Naveen Negasha, TronicsZone as per consultant&#39;s contract for hire.  
         [0054]     Countdown Timer Parts List below itemizes the existing electronic components used as depicted in  FIG. 3  showing the Countdown Timer schematic of the present invention.  
                                                 Countdown Timer Parts List            Qty   Part Name   Value   PBC Marking               3   Switch, tact, 4 pin, (12 mm)       MINUTES, SECONDS, SET_TIME       1   Switch, tact, 2 pin       RESET       2   Connector, Power, coaxial 2.1 mm       J1, J2       1   Solder points       BAT       1   Connector, relimate, 6 pin       PROG       6   Capacitor, SMD, 0603   0.1 uf   C1, C4, C5, C6, C9, C10       2   Resister, SMD, 0603   1k   R3, R11       1   Diode   1N4007   D5       3   Diode   1N5819   D1, D3, D4       4   Resister, SMD, 0603   2K2   R10, R16, R20, R24       1   Resister, SMD, 0603   3K3   R2       1   Crystal, HC49   4 MHz   Q2       1   Resistor, CFR, 2 W   5E6 (2 W)   R1       3   Resistor, SMD, 0603   10K   R5, R12, R23       2   Capacitor, SMD, 0603   22 pF   C7, C8       1   Resistor, SMD, 0603   39K   R8       2   Resistor, SMD, 0603   100K   R6, R7       1   Capacitor, polarized   100 uF/16 v   C3       1   Capacitor, polarized   100 uF/25 v   C2       1   Resister, SMD, 0603   220K   R4       9   Resistor, SMD, 0603   330E   R9, R13, R14, R15, R17,                   R18, R19, R21, R22       1   IC   ATMEGA48V-10AI   IC2       1   LED, Yellow, 3 mm   BAT LOW   D8       1   Transister, SMD, SOT23   BC848   T2       4   Transister, SMD, SOT23   BC858   T3, T4, T5, T6       1   Diode, Zener   C3V3PH   D2       1   LED, Green, 3 mm   CHARGING   D7       1   Transister, SMD, SOT223   FZT788B   T1       4   Display, Common anode   KLS351-CA   DIS1, DIS2, DIS3, DIS4       1   MOSFET, DUAL   IRF7307   Q1       1   IC   LP2950   IC1       1   Connector, Stereo socket   PG203J   X1       1   LED, Red   SUPPLY IN   D6       1   PCB   CNT-DN-TMR-1.0       1   Battery   6 V, 1.3 Ah       1   Output Cable   —       1   Tilt switch cable assembly   —                  
 
         [0055]     Count Down Timer—Hardware Description  
         [0000]     Document Version Date Description  
         [0000]     v1.0 25 Aug. 2005 First release of this document By Naveen Negasha, TronicsZone as per contract for hire.  
         [0000]     Table of Contents  
         [0056]     1. Power Supply, Voltage Regulator, Battery Charger  
         [0057]     2. Micro-controller  
         [0058]     3. The Displays  
         [0059]     4. The O/P Load Driver  
         [0060]     5. The User Interface  
         [0061]     1. Power Supply:  
         [0062]     Voltage Regulator:  
         [0063]     The circuit works at a regulated 3.3 v DC. A voltage regulator LP 2950 is used for the purpose of regulating the 9 v DC input. A battery backup is also provided for smooth operation of the Timer. The Regulator is supplied with, both the voltages, from battery (6 v) and the external power source (9 v). These are fed to the regulator through two Diodes (D 1  and D 2 ). D 1  will avoid the external power source from loading the Battery, and the D 2  will avoid the high voltage input directly fed to the Battery. The filter capacitors C 1 -C 4  are provided at the input and the output of the Regulator.  
         [0064]     Battery Charger:  
         [0065]     The voltage across the battery is continuously monitored by the Micro controller for Over/Under Voltage protection to the Battery. If the same is found dropped bellow the pre-set threshold of 5.75 v, the “BAT LOW” (YELLOW) LED will be ON. The Charger will be on whenever the Battery voltage reaches 5.2 v, and as an indication the “CHARGING” (GREEN) LED will be ON. The Charger consists of two transistors T 2  and T 3 . The Charger Control from the Micro Controller will go high as soon as the voltage across the battery drops to 5.2 v. This will put the T 1  in ON state, now the R 3  (1 K) and the Zener Diode D 3  (2.7 v) together will provide a constant voltage at the base of T 1 . The T 1 , while it is ON, will provide the battery with a constant current (Ich) which can be calculated as per the following Equation. 
 
 Ich =( Vz− 0.7)/ Re  
 
         [0066]     Ich: The Battery charging current  
         [0067]     Vz: The Voltage across the Zener Diode  
         [0068]     Re: The resistance connected at the Emitter of T 1   
         [0069]     The CHARGING LED is connected to the collector of the T 1 ; so that when ever the Charger is ON and the external power source is connected the LED will indicate the charging.  
         [0070]     2. Microcontroller: An Atmel AVR series microcontroller “ATMEGA48” is used as a processor in this project. The microcontroller forms the brain of the circuit and it controls all the functions of the Count down timer including battery charging, count down, sensing tilt switch, setting the timer, controlling the load, controlling the LEDs etc.  
         [0071]     3. The Displays:  
         [0072]     The Count down timer has four common Anode type 7-Segment Displays, to display the Minutes and Seconds. These are multiplexed by four PNP Transistors (T 3 -T 6 ). The seven segments are connected to the Micro Controller through current limiting resistors.  
         [0073]     4. The O/P Load Driver  
         [0074]     The system can drive a load with the rating of 6 v/2 A during the Count Down. The OUTPUT will be supplied from the battery. A fully charged (6.9 v) battery will serve the Load nearly 20 to 30 Minutes @ 6.0 v/2 A. The Load is switched On/OFF through an N-Channel FET (Q 1 ) which has a current rating up to 3 A. The resistor R 7  will always keep the Gate at the GND potential, so that the load is disconnected as long as the output from the controller is LOW. As soon as the Gate goes high the FWT will be put ON, and the Load will be served with the 6 v from the Battery. The Load will be ON during the Count Down, and will be put OFF when the Count reaches “00 00”. During the Count Down the Battery Charger will be put OFF.  
         [0075]     5. The User Interface  
         [0076]     The “Count Down Timer” has been provided with three (3) “Push to On” type switches, which are labeled as “SET TIME”, “MINUTES”, and “SECONDS”. Three LEDs, which are labeled as “POWER”, “CHARGING” and “BAT LOW” are also provided for indicating the various Power statuses. The User Manual can be referred for more details. The user interface is entirely controlled by the microcontroller.  
         [0077]     The following Countdown Timer Flow Chart below submitted By Naveen Negasha, TronicsZone, as per contract for hire. with the schematic and components parts list shows the flow of current and function of components as described above. 
         
 
         [0078]     The Countdown Timer, microprocessor&#39;s programmable memory is factory programmed by means of computer interface, wherein the programming files on the accompanying CD labeled “Countdown Timer Programming and Instuctions” Copy 1, are down loaded to the memory of the countdown timer, from a IBM-PC with a MS-Windows NT/2000/XP operating system, consisting of the following files;  
         [0079]     Disk labeled: Countdown Timer Programming and Instructions Copy 1, written  
         [0080]     To disk on Dec. 15, 2005. Copy 2, written To disk on Dec. 15, 2005.  
                                                                                 Date Modified:   Type of file:   File size:   Date loaded to disk:                                    Files on disk:                       Cntdwntimr   Jul. 01, 2005   C File   16.5 KB     Dec. 15, 2005       CntDwnTimr   Jun. 30, 2005   ASM File   50 KB    Dec. 15, 2005       CntDwnTimr   Jun. 30, 2005   INC File   1 KB   Dec. 15, 2005       cntdwntimr.c˜   Jun. 30, 2005   C˜File   17 KB    Dec. 15, 2005       CntDwnTimr.eep   Jun. 30, 2005   EEP File   1 KB   Dec. 15, 2005       Cntdwntimr   Jun. 30, 2005   H File   4 KB   Dec. 15, 2005       CntDwnTimr   Jun. 30, 2005   Error Log   1 KB   Dec. 15, 2005       CntDwnTimr.cof   Jun. 30, 2005   COF File   7 KB   Dec. 15, 2005       CntDwnTimr   Jun. 30, 2005   OJB File   8 KB   Dec. 15, 2005       CntDwnTimr   Jun. 30, 2005   Text Document   5 KB   Dec. 15, 2005       cntdwntimr.h˜   Jun. 30, 2005   H˜File   4 KB   Dec. 15, 2005       CntDwnTimr.hex   Jun. 30, 2005   HEX File   5 KB   Dec. 15, 2005       CntDwnTimr.ls˜   Jun. 13, 2005   LS˜File   75 KB    Dec. 15, 2005       CntDwnTimr.lst   Jun. 30, 2005   LST File   80 KB    Dec. 15, 2005       CntDwnTimr.map   Jun. 30, 2005   MAP File   2 KB   Dec. 15, 2005       CntDwnTimr.pr˜   Jun. 27, 2005   PR˜File   4 KB   Dec. 15, 2005       CntDwnTimr.prj   Jun. 30, 2005   PRJ File   4 KB   Dec. 15, 2005       CntDwnTimr.rom   Jun. 30, 2005   ROM File   11 KB    Dec. 15, 2005       CntDwnTimr.vec   Jun. 30, 2005   VEC File   1 KB   Dec. 15, 2005       CntDwnTimr —     Jun. 30, 2005   C File   17 KB    Dec. 15, 2005       CntDwnTimr_cof   Jun. 7, 2005   APS File   3 KB   Dec. 15, 2005       swart   Jun. 6, 2005   C File   2 KB   Dec. 15, 2005       swart   Jun. 8, 2005   H File   1 KB   Dec. 15, 2005       swart   Jun. 8, 2005   H˜File   1 KB   Dec. 15, 2005       Firmware loading       instructions   Jun. 30, 2005   Wordpad Document   119 KB    Dec. 15, 2005       _sp12dev   Jun. 20, 2005   File   33 KB    Dec. 15, 2005       _sp12rc   Dec. 9, 2005   File   4 KB   Dec. 15, 2005       decoder.eep   Jun. 18, 2005   EEP File   1 KB   Dec. 15, 2005       decoder.hex   Jun. 18, 2005   HEX File   5 KB   Dec. 15, 2005       giveio   Apr. 4, 1996   System File   6 KB   Dec. 15, 2005       install   Sep. 27, 2003   MS_DOS Batch File   1 KB   Dec. 15, 2005       instdrv   May 14, 1999   Application   157 KB    Dec. 15, 2005       lock   Jun. 24, 2005   MS_DOS Batch File   1 KB   Dec. 15, 2005       sp12   Feb. 17, 2003   Application   58 KB    Dec. 15, 2005       sp12   Feb. 7, 2003   Text Document   48 KB    Dec. 15, 2005       sp12dev   Jan. 28, 2003   Text Document   9 KB   Dec. 15, 2005       uninstall   Sep. 27, 2003   MS_DOS Batch File   1 KB   Dec. 15, 2005       upload   Jun. 30, 2005   MS_DOS Batch File   1 KB   Dec. 15, 2005                  
 
         [0081]      FIG. 4  is a cutaway view of the solenoid safety valve  44 , comprised of a valve body  60 , consisting of an inlet chamber  64 , and an outlet  66 , externally or internally threaded to accept NPT  62 , of a size necessary to connect to the water feed line of the toilet used. A flow port  68 , of sufficient diameter allows the water flow between the inlet chamber  64 , and the outlet chamber  66 . At the outlet chamber end of the flow port  68 , is a valve seat  70 . A valve seal  72 , stops the flow of water through said flow port  68 , when in contact with said valve seat  70 . The valve seal  72 , is opened and closed by means of a valve shaft  76 , to which it is permanently affixed. Said valve shaft  76 , is made of material suitable to magnetic pull. Said valve shaft  76 , moves towards a valve shaft end plug  84 , made of suitable magnetizable material by means of an electromagnetic field generated within a valve shaft chamber  82 , being forced closed by means of a valve shaft spring  80 , when there is no power to created said electromagnetic field. Said valve shaft  76 , is able to move into the open position easily without resistance due to back pressure reduction by means of a valve shaft flute  78 , which allows the water at said plug end  84 , to move freely towards said valve seal end  72 . Said valve shaft chamber  82 , is surrounded by a valve shaft chamber wall  88 , and is molded to a valve shaft chamber base  86 . Said chamber base  86 , is mounted to said valve body  60 , by means of four chamber base mounting screws  90 , and sealed by means of an o-ring  74 , of suitable material. An electromagnetic field is generated by means of a solenoid coil wire  94 , of suitable gauge and length to create said field by means of winding said wire around a solenoid coil spool  92 , and placing said coil spool  92  over the valve shaft chamber wall  88 . To charge said coil  94 , electric current of the proper voltage must be introduced by means of a positive lead wire  96 , and a negative lead wire  98 . Said solenoid coil wire  94 , is covered by means of a solenoid coil casing  100 , held in place by means of a solenoid casing screw  102 . Said positive lead wire  96 , and negative lead wire  98 , pass through said solenoid coil casing for access to electrical current to create the electromagnetic field needed to open said valve seat  72 .  
         [0082]     Those skilled in the art will appreciate that various adaptations and modifications of the just-described preferred embodiments which can be configured without departing from the scope and spirit of the invention. Therefore, it is to be understood that, within the scope of the appended claims, the invention may be practiced other than as specifically described herein, such as use of a larger volume solenoid safety valve  44 , on a tank-less toilet or urinal and using a push button to start the countdown in place of a tilt switch  36 , to activate the flush cycle, or with any other electronically controllable device.