the following describes an aquarium control system with a heater , but it is obvious that the invention would apply to such things as an aquarium with a cooling device or other tank of water . referring to all of the figures but in particular to fig1 a tank 10 is normally mounted on a leg supported stand 11 and generally comprises four transparent walls 12 , 13 , 14 and 15 . normally tank 10 is enclosed by a removable top 16 which will have a fluorescent light or incandescent light 17 mounted thereunder . mounted beside the tank is one form of filtering apparatus 18 which has a pipe 19 for removing material to be filtered into filter 18 and a pipe 20 which is coupled to pump 21 . the return for pump 21 is provided through a pipe 22 to the bottom of the tank for returning water usually in the form of aerated water to the tank , such is well known in the art and is not part of this invention . the tank may also contain a temperature control device such as a heater 23 , which will be coupled through wire means 24 to a control output 25 of a control system generally referred to by arrow 26 . an automatic feeding device 27 is likewise connected through a wire means 28 to a control output 29 of control system 26 . a thermistor 30 is mounted in the tank at a location below the surface 31 of water generally referred to by arrow 32 which , of course , is confined in tank 10 by wall 12 , 13 , 14 and 15 and a bottom not numbered . a wire means 33 couples thermistor 30 to a circuit 34 of control system 26 . light 17 is coupled through a wire means 35 to a control output circuit 36 . pump 21 is powered through a wire means 37 to a control output 38 of control system 26 . a 110 volt power source is coupled through a plug 39 and wire means 40 to the 110 volt input 41 of control system 26 . in case a second aquarium is desired , such second aquarium 42 may be coupled from its input 43 through a cable 44 to an output 45 of control system 26 . it is obvious that cable 44 will contain all of the wires 37 , 35 , 33 , 28 and 24 coupling aquarium number one , and in addition will include a 110 volt power source communicating power from control system 26 to second aquarium 42 . referring in particular to control system 26 , such system includes a keyboard data entry apparatus 50 having a plurality of keys illustrated as being numbered 0 through 9 and other keys having labels such as time , temperature , etc . it likewise contains a display portion 51 . display portion 51 , as will be described later in this specification , will display the various functions being entered into control system 26 along with the time of day and pertinent information for setting up and operating a control system . control system 26 also includes an alert light 52 and may also include a speaker 53 for an audible alarm if desired . the system also includes an on / off switch 54 along with several selected data entry keys represented by squares on the panel of control system 26 along with their function in writing beside the squares . the squares actually represent keys which may be pushed in order to activate the particular function desired . the keys may or may not light when depressed . referring to fig2 control system 26 is illustrated as a block diagram , so that the function of control system 26 can be better explained . the actual circuitry illustrated in fig2 is illustrated in fig3 and will be discussed at a later portion of this specification . referring in particular to fig2 a computer element 60 receives its power from a power supply 61 which has an 110 volt , for example , inlet 41 and supplies 5 volt output regulated at line 62 and a 5 volt dc unregulated at 63 for connection to the display portions of control system 26 . the power supply likewise is coupled through a wire 64 which provides 50 / 60 hertz for timing , such timing signal is applied to input 65 of computing element 60 . data input means 50 is illustrated in fig1 as being a keyboard . it is obvious that data input means 50 can likewise be a rom or other preprogrammed microprocessing unit or chip for inputting the necessary data to computing element 60 through a wire means 66 . computing element 60 has wire means 67 coupled to a display and driver 51 . it also provides an input through a wire 68 from an analog to digital converter ( a / d ) 69 which is subsequently coupled through a wire 70 to temperature sensing means 30 . computer element 60 has another wire means 71 coupled to an audible alarm such as speaker 53 . computer element 60 has a plurality of control outputs coupled through wires 72 , 73 , 74 and 75 to solid state relays 76 , 77 , 78 and 79 , respectively . each of the solid state relays 76 through 79 is coupled through a wire means 35 , 24 , 37 and 28 to the respective control apparatus 17 , 23 , 21 and 27 , respectively , said units being the light , heater , pump and food dispensing mechanisms respectively . the operation of the system is broadly described with reference made to fig1 and 2 . in order to properly control all of the functions requiring time , an initial time of day must be entered into the microprocessor from control system 26 . the time is normally entered by pressing the set button and the time button and then entering the time with keyboard data entry apparatus 50 . finally , the set button is pressed again to enter the data into the microprocessor . the p . m . may be indicated by pressing the button labeled p . m ., which , in the case shown in the illustration , is the 0 button . provision may be made to cancel the information already entered by pressing the clear button . the temperature desired for the aquarium is entered by pressing the set button and the temperature button and then entering the data as described for the clock , by pressing the proper keys on the keyboard 50 . the pump is then set by setting the pump off time or the pump on time and the set as indicated for the light and the temperature . furthermore , the light time on and time off is set similar to the described for the pump . the system also includes a feed time button , that is the time for actually feeding the fish can be entered . furthermore , the amount of feed can be set by the feed por button , representing the number of portions fed at any feeding time . at anytime a person desires the manual button can be pressed and the system operated manually . it is obvious , of course , the system may have a battery pack for maintaining the memory system alive during power failure or outage of the 110 volt circuit inputted through plug 39 to wire 40 at input 41 . referring in particular to fig2 in order to control the light , as an example , data input means 50 has inputted through wire 66 to computer element 60 the time of day to turn the light on and the time to turn it off . a signal is transferred through wire 72 during the on period of the light , which operates solid state relay 76 , communicating power through wire 35 to light 17 turning the light on . when it is time that the light should be shut off computer element 60 removes the signal to wire 72 , shutting solid state relay 76 off , thus , terminating power through wire 35 to light 17 . the heater likewise is controlled in the same manner as light 17 by information from computing element 60 being transferred through wires 73 to solid state relay 77 , either turning the power on or off to the heater as needed . as a consequence , power is transferred through wire 24 to heater 23 when solid state relay 77 is closed and power is terminated through wire 24 to heater 23 when solid state relay 77 has been opened . the same circuit 78 functions with pump 21 by communicating power through wire 37 and solid state relay 79 turns the food dispensing system on or off by supply power through wire 28 to food dispenser system 27 . one of the unique features of this invention is the method for controlling the heat in tank 10 . basically the temperature is sensed through a thermistor 30 . computer element 60 is connected by wire 68 to a / d converter 69 which senses the current through termistor 30 . the current passing through thermistor 30 will correspond to the temperature of the water in tank 10 . furthermore , one can utilize the self - heating aspects of thermistor 30 by forcing more current through the thermistor to determine whether the thermistor is in or out of the water . thus , referring to fig1 if the water level should drop to a point 47 which is at or below the level of thermistor 30 , the rate of heating of thermistor will be greatly varied from that when thermistor 30 is actually immersed in water . if computing element 60 senses that thermistor 30 is not in water , it can activate the audible alarm 53 through wire 71 transmitting a warning to the operator of tank 10 that the water level is below that necessary for the proper environment of the fish contained therein . furthermore , it has dropped below the level of thermistor 30 so additional water must be added to the tank in order to properly control the heat . the alarm can also be a light 52 , as illustrated in fig1 . light 52 , for example , can blink rapidly on and off to warn the operator of the condition of the water . it is obvious , of course , that a voice module can also be included to generate a spoken voice indicating to the operator the actual problem with the aquarium , such a voice module is well within the skill of the art and will not be further described . pump 21 can be set to operate in almost any mode desired by the operator . for example , during the feeding time the pump operation can be terminated so that the feed will not be sucked up into the filtering system of the aquarium , thereby permitting the food to float along the surface of the water rather being drawn down into the gravel , thereby contaminating the aquarium . this function is selected by pressing auto . referring to fig3 an embodiment which has been reduced to practice is illustrated . as many numbers as possible will be used for like or similar parts in fig3 as was used in the description of fig1 and 2 . power supply 61 has a first voltage output 80 labeled 6 . 3 volts . the voltage is supplied to the circuits as needed . the power supply likewise has a third voltage output labeled 62 which provides regulated 5 volts to all of the computer circuits . chip 180 provides a regulated power output through wire 62 of 5 volts as indicated . each of the circuits for controlling the food dispenser , the heater , the light and the pump are substantially identical , so only one of them will be described . the food dispenser is controlled from an output of microprocessor 60 through a wire 81 to the input 82 of a moc3009 opto isolator 84 which has an output along wire 83 to a triac 79 ; these elements constitute a solid state relay ( ssr ). the output from triac 79 is through a wire 85 to a control solenoid 86 of automatic feeding device or food dispenser 27 . a remaining wire 87 from solenoid 86 is coupled to one side 88 of 110 volt input 41 . the other side of 110 volt input 41 is wire 89 which is connected to an input 90 of triac 79 . the only difference between food dispenser connections through a solenoid 86 and the heater light and pump connections is that rather than having a solenoid 86 as illustrated , the wires are connected to plugs 92 , 93 and 94 respectively into which the respective apparatus are plugged . the display elements 51 , shown as multiple leds , are driven by drivers 104a , 104b , and 97 . the outputs 105a and 105b are operatively connected to inputs 103a , 103b , 103c and 103d . driver 97 is likewise connected to 103a through 103d by output means 98 through 101 , respectively . these drivers in turn are controlled by computing element 60 through a plurality of output signals . keyboard 50 , likewise , has a plurality of wires 102 , 95 , which are coupled to the output circuits of microprocessor 60 . in case a second aquarium 42 ( see fig3 ) is desired , then cable 44 is plugged into the output plug 45 and coupled to a remote unit for operating the second aquarium 42 or other environmentally controlled apparatus . the remote unit 107 which is coupled to computing element 60 through wire means 108 will , of course , contain solid state switches along with their corresponding opto isolation chips , feeder solenoid and mechanism and plugs for light , heater and pump . the operation of the circuit shown in fig3 is substantially the same as that previously described with fig2 . thus , if the timing element in microprocessor 60 determines that it is a proper time to operate dispenser 27 ( see fig1 ), then a signal is supplied from the output labeled 01 to the isolation unit 84 with the output from 84 on wire 83 rendering the triac 79 conductive causing current to pass from wire 89 through 90 through triac 79 through wire 85 to solenoid 86 and return through wire 88 . thus , when relay 86 is energized it will cause the dispenser to operate and drop a portion of food into the aquarium . if several portions are called for , the solenoid will be operated several times . the same procedure is followed for each of the heater , light and pump units . the display units 51a through 51d are well known in the art and their function and operation need not be explained . wires 95 , 102 are scanned by microprocessor 60 to determine which key has been depressed . only four display units have been illustrated . it is obvious that more than four units can be used as necessary for the proper display of any information inputted into or from microprocessor 60 . in an unit constructed in accordance with this invention microprocessor 60 is a motorola 6805 r3 microprocessor which contains a built in a / d convertor ; regulator chip 80 is a 78mo5 ; isolation chips 84 are moc3009 opto isolators ; display units 51a through 51d are any type of display desired by the person constructing the apparatus ; they can be led displays or illuminated displays or any other useful method for displaying information . if leds are used , then display driver 97 can be a 75492 and units 104a and 104b are 75491 . triac 84 are mac 3010 or other triacs well known in the art . an extremely versatile microprocessor controlled environmental control system has been described and its operation explained using an aquarium as an example . the system provides precise control over the water temperature , feeding time and amounts , pump conditions and light provided for the aquarium . it is obvious also that other elements can be incorporated in precisely the same manner , such as means for measuring the acidity of the water and other useful functions which may from time to time be necessary in other environments . for example , if the water being contained in the aquarium is salt water , then other conditions must be monitored such as the percentage of salt in the water , for example . it is also obvious that charcoal can be dispensed from the dispenser , thereby regulating acidity or salinity . it is obvious that other modifications and changes can be made using the teachings of this invention as described in the specification and appended claims and still be within the spirit and scope of this invention as described in the appended claims .
apparatus for controlling the environment of a tank adapted to be filled with water where the tank includes a plurality of control apparatus . the invention specifically utilizes a microprocessor having a plurality of control signal inputs and a plurality of control signal outputs . apparatus is provided for coupling each of the control signal outputs to each of the plurality of control apparatus . a program device is coupled to the microprocessor signal input such that data can be entered for the control of each of the plurality of control signal outputs and a timing apparatus is likewise coupled to one of the plurality of signal inputs in a manner to allow the microprocessor to calculate the time of day such that data entered by the program device will selectively control the function of each of the control apparatus as necessary to maintain the environment within the limits set by the operator .