Abstract:
An electronic control unit for the control of automatic watering systems having plural lines comprising an electronic circuit with a programmable processing unit for the control of a plurality of different watering lines. A manually operated selector, preferably of the rotary type, is provided, that is settable in a plurality of selectionable positions, to each one of which a specific watering cycle for the lines corresponds. By acting on the selector and on a start button, it is possible to modify the programming of the processing unit in order to associate with each single line a respective watering cycle different from the ones otherwise selectable by means of the selector.

Description:
TITLE OF THE INVENTION 
     “Electronic control unit with modifiable pre-set programs for the control of automatic watering systems with plural lines” 
     BACKGROUND OF THE INVENTION 
     The present invention refers to an electronic control unit with modifiable pre-set programs for the control of automatic watering systems having plural lines. 
     The increasing demand for watering systems capable to activate and to disconnect themselves at programmable pre-fixed intervals and for time lengths is known. 
     This gave rise to a corresponding increase in the designing of electronic control units for the control of the aforementioned systems. 
     Among the control units with easiest employment by the user there is the one described in the European patent application EP-A-0748584 of the same applicant, in which a rotary selector that at the time of its utilisation can be positioned in a plurality of different angular positions, each one corresponding to the selection of a respective watering cycle, is provided. 
     With this type of control unit the user can avail beforehand of a certain number of watering cycles, among which the user can choose the most convenient one, simply by setting the rotary selector in the angular position corresponding to the desirable cycle, opportunely indicated by a numeric index and/or an inscription. 
     This known control unit is however suitable for the control of one watering line and more precisely of one electro-valve or other type of actuator. 
     In addition, the pre-set cycles are fixed and there is no possibility of their modification by the user. 
     On the other hand there is the development of a large market for control units capable to control plural watering lines and that provide for cycles modifiable according to the needs of the single user. 
     At the same time the ease of employment associated with the existence of pre-set cycles that do not require, for their pre-setting, the intervention of specialised personnel at the user&#39;s who purchased the control unit continues to be appreciated. 
     SUMMARY OF THE INVENTION 
     In view of the state of the art, object of the present invention has been to provide an electronic control unit, that would be suitable for the control of plural watering lines and, having a certain number of pre-set cycles, would however allow to modify those cycles so as to adjust them to the specific needs of the single user. 
     According to the invention, such object has been attained with an electronic control unit comprising an electronic circuit with a programmable processing unit and a manually operated selector positionable in a variety of selectionable positions, to each one of which a specific watering cycle corresponds, characterised in that said electronic circuit is arranged in such a way as to control in sequence a plurality of distinct watering lines and means are provided for modifying the programming of said processing unit so as to associate a respective watering cycle, different from the ones otherwise selectable by means of the selector, to each single line. 
     In this way, the user avails of a control unit utilisable for plural watering lines, with which he can select in an extremely simple and quick way any watering cycle comprised among a plurality of pre-set cycles. Besides, he has the possibility to disregard the pre-set cycles in favour of new cycles, possibly different for the different lines, which are more suitable for the particular needs of the system being controlled. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The characteristics of the present invention will be better explained hereinafter by referring, as a non-limiting example, to the enclosed drawings, where: 
     FIG. 1 shows a perspective view of a control unit according to the present invention; 
     FIG. 2 shows the control unit in longitudinal section according to line II—II of FIG. 1; 
     FIG. 3 shows in top plan a fore external area of the control unit, that comprises a selector of modifiable pre-set watering cycles, in an enlarged scale and with the cover removed; 
     FIG. 4 shows in top plan a back internal area of the control unit, in an enlarged scale and with the cover removed; 
     FIG. 5 shows a block diagram representing the electronic circuit of the control unit. 
    
    
     DESCRIPTION OF THE INVENTION 
     The control unit shown in FIGS. 1-5 has a box casing  51  formed by a base  52 , by a fore cover  53  of substantially flat shape and by a higher back cover  54  joined to the fore one by means of an oblique wall  55  (FIGS.  1  and  2 ). A transparent lid  56  revolving around pivot pins  57  provided on the back cover  54  is normally placed in the closed position of FIGS. 1 and 2 as a protection of the fore cover  53  and of the oblique wall  55 . 
     On a panel  58  of the fore cover  53  a program selector  59  is rotatably located, that is formed by a turning circular knob  60  with an index  61  settable in any one of a sequence of angular positions defined by position marks  1 - 28  (each corresponding to a specific watering cycle), P and OFF (FIG.  3 ). 
     On the flat fore cover  53  two buttons  62  and  63  with indicating inscriptions START and STOP RAIN 24H are also provided, as also six adjacent light indicators  64  and an additional light indicator  65  at a distance from the previous ones. 
     On the oblique wall  55  the same position marks  1 - 28 , P and OFF are provided, with adjacent inscriptions indicating the watering cycles corresponding to the various angular positions of the selector  59 . 
     The selector  59  and the buttons  62  and  63  are accessible by the user by lifting the transparent lid  56  by rotation around the pivot pins  57 . 
     As shown in FIG. 2, the knob  60  of the selector  59  has a pin  66  that passes through the flat fore cover  53  and bears a fixedly mounted small plate  67 , below the cover itself, provided with a sliding contact element  68  which co-operates with an electronic circuit (non shown in details) formed by a circuit card  69  placed as a covering of a first chamber  70  defined in the fore part of the base  52  for the housing of one or more buffer cells (not shown) insertable through a lower opening with removable door  71 . 
     The back cover  54  together with the back part of the base  52  defines in turn a second chamber  72  in which a voltage transformer  73  kept in position by angular posts  74  (FIGS. 2 and 4) is housed. 
     Inside the chamber  72  a terminal board  75  is also housed (FIG. 4) suitable for the electrical connection of the transformer  73  with input electrical wires (not shown) at a mains voltage (220V), that enter the same chamber through an inlet opening  76  and are locked in their positions by a fixing over-crossing plate (FIG.  4 ). 
     The two chambers  70  and  72  are separated by a divisor septum  78 , which also acts as a housing for a terminal board  79  formed by a plurality of single elastic plate terminals with activation lever  81  (FIG. 2 and 4) of the type described in the Italian patent application MI96A001563 of Jul. 25, 1996. The terminal board  79  serves the function to fix the connection electric wires (not shown) between the transformer  73  and the electronic circuit mounted on the circuit card  69  and output electric wires (not shown) of the aforementioned electronic circuit, that are connected with the actuators of the watering system to which the control unit is destined, through a lateral opening  82  on the base  52  (FIG.  2 ), in such a way as to provide for the command of the activation of respective water feeding lines of the system. 
     The electronic circuit associated with the circuit card  69  is represented in the form of a block diagram in FIG.  5  and comprises essentially a processing unit with programmable microprocessor  83  controlled by the rotary selector  59  and by the buttons  62 - 63  and controlling in turn the light indicators (LED)  64  and  65 . In addition, the processing unit  83  is controlled by a selector  84  (not shown in the mechanical drawings), that provides for the selection of the number of exits to be controlled (for example, 4 or 6) and/or for the selection of the supply frequency (for example, 58Hz or 68Hz), and receives a low voltage alternating power supply (for example 24VAC) from the transformer  73  through a network frequency synchronism circuit  85 . The transformer  73 , or as an alternative a battery  86 , also provides for the power supply of the electronic circuitry  87  associated with the processing unit  83 . 
     The processing unit  83  provides for the control of a driving circuit  88  for the actuators (typically electro-valves) of the watering system, while a circuit  89  for the detection of short circuits provides for the stop of the processing unit  83 , and more generally of the control unit, in the event of short circuits in the same actuators. 
     Because of the aforementioned conformation, the control unit of FIGS. 1-5 must simply be connected to a normal network power socket, obviously besides to the actuators of the watering system. 
     The various watering cycles pre-set during the stage of preparation of the microprocessor  83  are indicated on the oblique wall  55  of the control unit cover (FIG.  3 ). However, it is possible to modify them, as it will be described later. 
     Before going on with the description of the control unit complete operation, the functions of buttons  62 - 63  and of the light indicators  64 - 65 , should be here considered. 
     The START button  62  has the following functions: 
     manual starting of the watering cycle pointed at by the rotary selector  59 ; 
     feeding of the watering cycle currently under course to the next exit; 
     start of programming when the rotary selector  59  points at the position P; 
     assignment of the watering time pointed at by the rotary selector  59  to the exit relative to the LED indicator currently lightened and lightening of the next indicator. 
     The STOP RAIN button  63  has the following functions: 
     setting in pause of the control unit for a period of 24 hours starting from the time in which the button is pressed; 
     restoring of the operation mode in the event the control unit is already in pause. 
     It should be noted that the STOP RAIN button will not have any effect when the rotary selector points at the OFF or the P position and during the programming stage. 
     The light indicator  65  concerns the power supply of mains and it operates according to the following ways: 
     lightened in a constant way, it indicates the presence of the mains power supply; 
     lightened in a slow intermittent way (for example, 0.5 sec. on, 0.5 sec. off) it indicates the absence of tension of mains and that the operation is granted by the battery. 
     The light indicators  64  concern the operation of the various exits connected to respective actuators of the watering system and they operate according to the following ways: 
     lightened in a constant way, each indicator  64  signals that the relative exit is active; 
     lightened in a slow intermittent way (for example, 0.5 sec. on, 0.5 sec. off) each indicator  64  signals that the respective exit is in short circuit. 
     lightened in a quick intermittent way (for example, 0.1 sec. on, 0.1 sec. off), each indicator  64  signals that the control unit is undergoing a stage of programming of the watering times. 
     lightened in a quick sequence from left to right the indicators  64  signal the state of pause. 
     Having premised this, the control unit can operate in AUTOMATIC, SEMI-AUTOMATIC, MANUAL, PROGRAMMING, PAUSE, OFF and ZERO HOUR modes. 
     The AUTOMATIC mode is the main operating mode, which allows to activate in a sequence all the available exits for the length of time (equal for all exits) indicated by the position in which the rotary selector  59  is set and at time intervals also associated with the position of the same selector. 
     According to this form of operation the rotary selector  59  must therefore be positioned in the angular position, to be chosen among  1 - 28 , that corresponds to the desirable watering cycle. 
     In order for the cycle to be activated at once, all the light indicators  64  must be off. If one of them is lightened in a constant way, thus indicating that an exit is active, the starting of the cycle is delayed until the end of the interval subsequent to the turning off of the active exit. This can depend either on the previous starting of a cycle in SEMI-AUTO mode on request of the user, or on the fact that, as a consequence of a programming that modified the watering times, the length of the cycle turns out to be superior to the starting interval between two subsequent cycles. 
     It must be noted that the change in position of the rotary selector  59  interrupts a possible cycle of watering under course. 
     For the SEMI-AUTO operation mode it is necessary to position the rotary selector  59  again in one of the angular positions  1 - 28 . No exit indicator  64  must be flashing in a quick way or be lightened in a fix way. 
     The START button  62  is then pressed once, and it allows to start, upon command of the user, a complete watering cycle that provides to activate in a sequence all the available exits for the length of time (equal for all exits) indicated by the position in which the rotary selector is set and with time intervals also associated to the angular position of the same selector. 
     At the start of the MANUAL mode at least one light indicator of an exit  64  is lightened in a fix manner. The START button  62  is then pressed one or more times. This allows to turn off the exit currently on and to activate the immediately subsequent one, and so on until all the available exits are run. Unless the START button is pressed ahead of time, the time length of the activation of the actuator currently in function is the one indicated by the position of the rotary selector  59 . 
     The PROGRAMMING mode allows to associate the single exits with watering cycles different from the pre-set one. To this purpose it is necessary to position the rotary selector  59  on P and to press the START button  62  once. With one of the light indicators  64  lightened in an intermittent quick way as to signal that a programming stage is running, the rotary selector  59  is then moved to one of the angular positions  1 - 28  and the START button is pressed again. This allows to associate the exit relative to the light indicator  64  currently being lightened in a flashing quick manner with the time length of the activation indicated by the new position of the rotary selector at the time in which the START button is pressed again. By repeating the same operation for the other exits, each exit can thus be set for the AUTOMATIC operation with a time length different from the ones indicated by the rotary selector  59 . 
     By pressing the START button during the PROGRAMMING mode with the rotary selector  59  in the position P or OFF a possible programmed time length associated with the relative exit gets cancelled, restoring the time lengths indicated by the rotary selector. 
     Once having entered the PROGRAMMING mode, it is possible to exit it in two ways: 
     pressing the START button until all the exit indicators  64  are turned off; 
     automatically at the mode moment of the automatic starting of the subsequent cycle. 
     For the PAUSE mode it is necessary to position the rotary selector  59  in one of the positions from  1  to  28 , making sure that no exit indicator  64  is flashing in a quick way. The RAIN STOP button  63  must then be pressed once. This allows to stop the watering for 24 hours since the time when the RAIN STOP button was pressed and therefore the exit indicators  64  lit in a quick sequence. Once in the PAUSE mode the watering can be restored by pressing the RAIN STOP button again. 
     The PAUSE mode is terminated when operating in the PROGRAMMING and OFF modes. 
     In order to activate the OFF mode the rotary selector  59  has to be positioned in the angular position OFF. In this way, all the exits are disabled and no additional watering cycle is permitted. 
     The mode ZERO HOUR is activated by pressing the two buttons START  62  and RAIN STOP  63  simultaneously. In this way the time in which this operation is performed is set as the starting time for the count of the watering intervals. 
     It must be noted that the initialisation of the “0” hour also occurs automatically when the electronic control unit is connected to the power supply, either of mains or battery.