A control device for automatic water discharge installed at position where water is discharged in apparatus for automatic water discharge in a kitchen and sanitary environment is provided. The device comprises a housing, a sensor unit disposed inside the housing, a water discharge unit, and an electromagnetic valve assembly. The housing comprises a first holding chamber configured to receive the sensor unit, a second holding chamber configured to receive the electromagnetic valve assembly, a third holding chamber configured to receive the water discharge unit, and a water intake chamber. The sensor unit comprises a circuit board and a sensor set at the circuit board. The circuit board is provided with a processor. The electromagnetic valve assembly comprises an electromagnetic valve electrically connected with the circuit board and a diaphragm unit. Motion of the diaphragm unit controls connecting and blocking between the water intake chamber and the third holding chamber to respectively realize water discharge or to stop water. The control device for automatic water discharge is designed as compact structures, and is conducive to the miniaturization of products.

CROSS-REFERENCE TO RELATED PATENT APPLICATIONS 
     This application is related to and claims priority to Chinese Patent Application No. 200910201203.6, filed Dec. 16, 2009, and incorporated herein by reference in its entirety. 
     BACKGROUND 
     The present disclosure relates to a control device for automatic water discharge and an apparatus for automatic water discharge which contains the above control device applied in kitchen and sanitation uses, such as an automatic sensing faucet, etc. 
     Automatic sensing technology is widely used in water discharge apparatuses in kitchens, sanitation, etc., for instance, in faucets, urinals, and so on. In the prior art, an automatic sensing faucet typically comprises a faucet body; and a detecting sensor for detecting whether there is any object (such as the hands of a user) entering/leaving the sensing area, an electromagnetic valve, and a control unit are connected with the faucet body. The detecting sensor can be a traditional infrared sensor, position sensing device (PSD), microwave detecting sensor, or ultrasonic wave detection sensor, etc. General speaking, the sensor is installed at the faucet outlet or on the faucet body. The electromagnetic valve and the control unit are installed under the basin of faucet. 
     The automatic sensing faucet has many elements, and both the electromagnetic valve and the control unit need to be installed below the basin, which is inconvenient during installation and subsequent maintenance, and is not conducive to miniaturization of the product. 
     SUMMARY 
     One embodiment of the present disclosure relates to providing a new type of control device for automatic water discharge and an apparatus for automatic water discharge including the control device. 
     Another embodiment of the present disclosure relates to a control device for automatic water discharge, mounted at a position where water is discharged from an automatic water discharge device in a kitchen or sanitation environment. The control device comprises a housing, a sensor unit contained inside the housing, a water discharge unit, and an electromagnetic valve assembly. The housing comprises a first holding chamber for containing the sensor unit, a second holding chamber for containing the electromagnetic valve assembly, a third holding chamber for containing the water discharge unit, and a water intake chamber. The sensor unit comprises a circuit board provided with a processor and a sensor coupled to the circuit board. The electromagnetic valve assembly comprises an electromagnetic valve electrically connected with the circuit board and a diaphragm unit cooperated with the electromagnetic valve. Motion of the diaphragm unit controls connecting or blocking between the water intake chamber and the third holding chamber to respectively discharge water or stop water. 
     According to one embodiment, the electromagnetic valve comprises a valve cover and an electromagnet disposed inside the valve cover. The electromagnet comprises a cylinder body, a valve core contained inside the cylinder body, and a coil set at two sides of the valve core. A cavity is formed between the valve cover and the diaphragm unit. 
     According to one embodiment, a water intake channel connected with the cavity and a water leak channel connected with the third holding chamber are set into the valve cover. Movement of the valve core controls connecting and blocking between the water intake channel and the water leak channel. 
     According to one embodiment, the electromagnet is horizontally set inside the valve cover; both the water intake channel and the water leak channel are positioned at the side of the valve cover adjacent to the valve core. 
     According to one embodiment, a leak hole connected to both the second holding chamber and third holding chamber is provided in the housing. The water leak channel is connected to the third holding chamber through the leak hole. 
     According to one embodiment, the diaphragm unit comprises a moving diaphragm and a moving plate provided on the moving diaphragm. A water supplement hole connected with the cavity is set at the moving plate. 
     According to one embodiment, a pin fitted with the water supplement hole is set at the diaphragm unit. 
     According to one embodiment, the circuit board comprises a first portion and a second portion. The sensor is installed at the first portion while the processor is installed at the second portion. After the sensor unit is mounted to the housing, the first portion of the circuit board is positioned at the surface of the front end of the housing with the sensor facing towards the sensing area, while the second portion is positioned inside the first holding chamber. 
     According to one embodiment, the circuit board is a flexible circuit board. 
     According to one embodiment, openings of the first and third holding chambers are positioned at the front end of the housing while openings of the second holding chamber and the water intake chamber are positioned at the back end of the housing. The water intake chamber is located at a first side of the second holding chamber. 
     Another embodiment of the present disclosure relates to an apparatus for automatic water discharge comprising a control device for automatic water discharge set at the position where the water is discharged from an automatic water discharge device. The control device for automatic water discharge is connected with a water pipe of the apparatus for automatic water discharge and comprises a housing, a sensor unit contained inside the housing, a water discharge unit, and an electromagnetic valve assembly. The housing comprises a first holding chamber for containing the sensor unit, a second holding chamber for containing the electromagnetic valve assembly, a third holding chamber for containing the water discharge unit, and a water intake chamber connected with the water pipe. The sensor unit comprises a circuit board provided with a processor and a sensor set at the circuit board for detecting if a user enters/leaves the sensing area of the apparatus for automatic water discharge. The electromagnetic valve assembly comprises an electromagnetic valve electrically connected with the circuit board and a diaphragm unit cooperated with the electromagnetic valve. The motion of the diaphragm unit controls connecting and blocking between the water intake chamber and the third holding chamber to discharge water or stop water, respectively. 
     According to one embodiment, the electromagnetic valve comprises a valve cover and an electromagnet set inside the valve cover. The electromagnet comprises a cylinder body, a valve core contained inside the cylinder body and a coil set at two sides of the valve core. A cavity is formed between the valve cover and the diaphragm unit. 
     According to one embodiment, a water intake channel connected with the cavity and a water leak channel connected with the third holding chamber are set into the valve cover. The movement of the valve core controls opening and closing between the water intake channel and the water leak channel. 
     According to one embodiment, a leak hole connected to both the second holding chamber and third holding chamber is provided in the housing. The water leak channel is connected to the third holding chamber by means of the leak hole. 
     According to one embodiment, the electromagnet is horizontally set inside the valve cover. The water intake channel and the water leak channel are positioned at the side of valve cover adjacent to the valve core. 
     According to one embodiment, the diaphragm unit comprises a moving diaphragm and a moving plate at the moving diaphragm. A water supplement hole connected with the cavity is set at the moving plate. 
     According to one embodiment, the diaphragm unit also comprises-a pin fitted with the water supplement hole. 
     According to one embodiment, the circuit board comprises a first portion and a second portion. The sensor is installed on the first portion while the processor is installed on the second portion. After the sensor unit is mounted to the housing, the first portion of the circuit board is positioned at the surface of the front end of the housing with the sensor facing towards sensing area, while the second portion is positioned inside the first holding chamber. 
     According to one embodiment, the circuit board is a flexible circuit board. 
     According to one embodiment, openings of the first and third holding chambers are positioned at the front end of the housing while openings of the second holding chamber and water intake chamber are positioned at the back end of the housing. The water intake chamber is located to one side of the second holding chamber. 
     According to one embodiment, the apparatus for automatic water discharge is an automatic sensing faucet. 
     Compared with the prior arts, the control device for automatic water discharge of the present invention is compact, and it is conducive to miniaturization of product. The apparatus for automatic water discharge having the control device installed is more compact, which provides convenient maintenance and installation. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of a control device for automatic water discharge, according to an exemplary embodiment. 
         FIG. 2  is an exploded view of the control device of  FIG. 1 . 
         FIG. 3  is a view of the control device of  FIG. 2  from another side. 
         FIG. 4  is a section view of the control device of  FIG. 1  along section line A-A of  FIG. 1 . 
         FIG. 5  is a section view of the control device of  FIG. 1  along section line B-B of  FIG. 4 . 
         FIG. 6  is a section view of the control device of  FIG. 1  along section line C-C of  FIG. 4 . 
         FIG. 7  is a section view of the control device of  FIG. 1  along section line D-D of  FIG. 4 . 
         FIG. 8  is a section view of the control device of  FIG. 1  along section line E-E of FIG.  5 . 
         FIG. 9  is a perspective view of an automatic sensing faucet including the control device of  FIG. 1  for automatic water discharge. 
     
    
    
     DETAILED DESCRIPTION 
     Exemplary embodiments of the present invention will be clearly described referring to the attached drawings. Elements having the same structure or function are marked with the same number. It is understood that the attached drawings are just for the description of the exemplary embodiments, not limitations of the present invention. Additionally, the attached drawings may or may not be drawn in proportion. 
     As shown from  FIG. 1  to  FIG. 3 , an exemplary embodiment of the present invention relates to a control device  100  for automatic water discharge which overcomes the shortcomings of the prior art, has the high integration and lends itself to miniaturization of product. Another embodiment relates to an apparatus for automatic water discharge which contains said control device  100  (such as automatic sensing faucet, etc., shown as  FIG. 9 ). 
     The control device  100  for automatic water discharge comprises housing  1 , sensor unit  2  installed in the housing  1 , electromagnetic valve assembly  3  electrically connected with the sensor unit  2 , and water discharge unit  4 . The control device  100  for automatic water discharge also comprises an end cover  5  which works as a seal. 
     Housing  1  is shown to be cylindrical and has several holding chambers. It comprises a first holding chamber  11 , configured to hold sensor unit  2 , a second holding chamber  12 , configured to hold electromagnetic valve assembly  3 , a third holding chamber  13 , configured to hold water discharge unit  4 , and water intake chamber  14  which connects with the water pipe of the apparatus for automatic water discharge. Water intake chamber  14  is shown to one side of second holding chamber  12 . This makes the structure more compact. Housing  1  also has a leak hole  15  which connects second holding chamber  12  and third holding chamber  13 . 
     Housing  1  comprises front and back ends, wherein the front end faces the user, and the back end is set in the apparatus for automatic water discharge and connects with water pipe. The openings of the first holding chamber  11  which holds sensor unit  2 , and third holding chamber  13 , which holds water discharge unit  4 , are at the front end of housing  1 ; the openings of second holding chamber  12 , which holds electromagnetic valve assembly  3 , and the water intake chamber  14  are at the back end of housing  1 . In an installed position, sensor unit  2  and water discharge unit  4  are approximately located at the front end of housing  1 . 
     Sensor unit  2  comprises circuit board  21 , which electrically couples with electromagnetic valve  31 , and a sensor (not shown on the drawings) which is set in the circuit board  21 . Wherein circuit board  21  also has processors and other electronic elements. The sensor may be an infrared sensor having an infrared emitter and an infrared receiver. According to other embodiments, the sensor can be a microwave sensor, an-ultrasonic sensor, or any suitable sensor configured to detect whether the objects enter or leave the sensing area. Circuit board  21  comprises a first portion  211  and second portion  212 . The sensor is set on first portion  211 ; an electronic element (device), such as the processor may be set on second portion  212 . A light-passing board  22  is also set on the external surface of first portion  211  of said sensor. The second portion  212  may be disposed in first holding chamber  11 , and light-passing board  22  of first portion  211  may form a surface of the front end of housing  1 . 
     In an exemplary embodiment, the circuit board  21  is a flexible circuit board, which enables second portion  212  to be foldable or curved, so second portion  212  can be accommodated in the first holding chamber  11  expediently. As shown, both the configuration of water discharge unit  4  and housing  1  are cylindrical. The shape of the first portion  211  of circuit board  21  and the light-passing board  22  are somewhat crescent-shaped, which enables the first part  211  and the light-passing board  22  to cooperate with water discharge unit  4  and to be set in the front surface of the front end of housing  1 . 
     Electromagnetic valve assembly  3  comprises an electromagnetic valve  31  and diaphragm unit  32  which cooperates with the electromagnetic valve  31 . The diaphragm unit  32  may be moved by means of opening and closing electromagnetic valve  31 . As shown, the diaphragm unit  32  is set under the electromagnetic valve  31 . 
       FIG. 4  is a section view along the A-A line on  FIG. 1 , and  FIG. 5  and  FIG. 6  are section views along the B-B line and C-C line on  FIG. 4 , shown according to an exemplary embodiment. The A-A line is along the line through the center of moving plate  322  and the center of water leak channel  317 . The B-B line passes through cavity  33 . The C-C line passes through the center of valve core  314  of electromagnet  312 . 
     According to the embodiment shown in  FIG. 4 , the electromagnetic valve  31  comprises a valve cover  311  and electromagnet  312  located in the valve cover  311 . As shown, the diaphragm unit  32  is located under valve cover  311 , and the cavity  33  is formed between diaphragm unit  32  and valve cover  311 . The electromagnet  312  comprises a cylindrical body  313 , a movable valve core  314  located in the cylindrical body  313 , and coil  315  set on the two sides of valve core  314 . The valve core  314  can move back and forth under the electromagnetic force by supplying or cutting off the power of electromagnetic valve  31 . Further, a cable  310  which connects electrically with circuit board  21  may be set on the electromagnetic valve  31 . 
       FIG. 7  is a section view along the D-D line on  FIG. 6 , shown according to an exemplary embodiment. The D-D line passes through the water intake channel  316 . 
     As shown in  FIG. 5  to  FIG. 7 , the water intake channel  316 , connected with the cavity  33 , and the water leak channel  317 , connected with the third holding chamber  13 , are set into the valve cover  311 . After the water discharge unit  4  is installed into third holding chamber  13 , the water leak channel  317  is connected to third holding chamber  13 , namely, the water leak channel  317  is connected to water discharge unit  4 . When the electromagnetic valve  31  is closed, the valve core  314  protrudes out. Water is blocked and can not flow through water intake channel  316  to water leak channel  317 , i.e., water intake channel  316  and water leak channel  317  are disconnected. When electromagnetic valve  31  is opened, the valve core  314  retracts into cylindrical body  313 . The water intake channel  316  is connected with the water leak channel  317 . In another embodiment, a sealing element is set around the free end of the valve core  314 , thereby improving the sealing effectiveness while the water intake channel  316  and the water leak channel  317  are blocked by the valve core  314 . 
     The diaphragm unit  32  further comprises a moving diaphragm  321  and a moving plate  322  mounted on the moving diaphragm  321 . The moving plate  322  has a water supplement hole  323  connected with the cavity  33 . The moving diaphragm  321  may be made from soft rubber materials, and the moving plate  322  may be made from hard plastic materials. In one embodiment, the diaphragm unit  32  comprises a pin  324  fitted through water supplement hole  323  to protect the water supplement hole  323  from being blocked by foreign matter (see  FIG. 8 ). When the diaphragm unit  32  operates, the moving plate  322  causes the moving diaphragm  321  to move. 
     In one embodiment, the electromagnet  312  is horizontally set in valve cover  311 , and water intake channel  316  and water leak channel  317  are positioned at the side of valve cover  311  adjacent to the valve core  314 . In other embodiments, the electromagnet  312  can be installed with any suitable angle. The water intake channel  316  and water leak channel  317  can be appropriately adjusted according to where said electromagnet  312  is mounted. 
     A water inlet  51  connected with water intake chamber  14  is set at the end cover  5 . The end cover  5  seals the back end of housing  1  except the water intake chamber  14 . A power cable (not shown on the drawings) connected with the circuit board  21  exits by passing through the cable opening  52  on the end cover  5 , and may then be connected to an external power source of the apparatus for automatic water discharge. The external power source can be a direct current supply or an alternating current (e.g., mains) supply. 
     In another embodiment, the end cover  5  is not required; it can be substituted by any sealing material which can effectively seal housing  1  except the water intake chamber  14 . 
     Moreover, as the water discharge part of the water discharge device, water discharge unit  4  can be a bubbler installed in automatic sensing faucets or a sprinkler installed in automatic sensing urinals. 
     Sensor unit  2  is installed into the first holding chamber  11  through the front end of the housing  1 . The first portion  211  of circuit board  21  may be installed such that the sensor is positioned at the surface of the front end of the housing  1  to locate the sensor at an ideal position. The housing  1  seals the circuit board  21  in the first holding chamber  11  to prevent water from entering the circuit board  21 . 
     The water discharge unit  4  is installed in the third holding chamber  13  through the front end of the housing  1 , and the outer side of the water discharge unit  4  is positioned at the surface of the front end of the housing  1 . In another embodiment, threads are provided on the outer face of water discharge unit  4  and the inner side of the third holding chamber  13 . The water discharge unit  4  is connected to housing  1  by the threads. The water discharge unit  4  can be connected to housing  1  by other means, such as screws or welding, etc. 
       FIG. 8  is a section view along section line E-E of  FIG. 5 , shown according to an exemplary embodiment. The section line E-E is along the straight line through the center of water supplement hole  323  and the diaphragm unit  32 . As shown, the electromagnetic valve assembly  3  is installed into the second holding chamber  12  through the back end side of the housing  1 . After the electromagnetic valve assembly  3  is installed into the second holding chamber  12 , the diaphragm unit  32  is positioned between water intake chamber  14  and the third holding chamber  13 . Motion of the diaphragm unit  32  controls the connecting and blocking between water intake chamber  14  and the third holding chamber  13 . After the water discharge unit  4  is installed into the third holding chamber  13 , water intake chamber  14  and the third holding chamber  13  are connected to each other or blocked, that is, water intake chamber  14  and water discharge unit  4  are connected with each other or blocked. After receiving water pressure from water in the cavity  33 , the diaphragm unit  32  is pressed to the position between water intake chamber  14  and the third holding chamber  13 , thereby blocking the connection between water intake chamber  14  and the third holding chamber  13 . Water in the water intake chamber  14  is sealed in water intake chamber. As shown in  FIG. 8 , the diaphragm unit  32  is right on the position to block the connection between water intake chamber  14  and the third holding chamber  13 . When water in the cavity  33  is released, the diaphragm unit  32  moves backward into the cavity  33 . The water intake chamber  14  is connected with the third holding chamber  13 . Thus, water in water intake chamber  14  will flow into the third hold chamber  13  and be discharged through the water discharge unit  4 . 
     After the electromagnetic valve assembly  3  is installed in housing  1 , the leak hole  15  is connected with water leak channel  317 . Therefore, water in the water leak channel  317  can flow into the third holding chamber  13  through the leak hole  15  and is discharged through water discharge unit  4 . In one embodiment, to ensure sealing, a portion of diaphragm unit  32  is located between water leak channel  317  and leak hole  15 . A small hole  325  is provided at diaphragm unit  32 , thus small hole  325  is connected with water leak channel  317  and leak hole  15  to form a channel for water flow. Water leak channel  317  can also be directly connected with leak hole  15 . Other sealing elements may be needed for sealing. 
     The end cover  5  is installed to the end side of the back end of housing  1  to seal electromagnetic valve assembly  3  and sensor unit  2 . Water inlet  51  of end cover  5  is connected with water intake chamber  14  of housing  1 . 
     Thus, assembling of the control device for automatic water discharge of the exemplary embodiment is completed. 
     For use, the control device  100  for automatic water discharge is installed in the an apparatus for automatic water discharge, such as automatic sensing faucet, automatic sensing urinal machine, and other automatic kitchen and sanitation water sources. The control device  100  for automatic water discharge is installed proximate the water discharging portion of the apparatus for automatic water discharge. 
     The following description describes use of the control device  100  for automatic water discharge in an automatic sensing faucet, according to an exemplary embodiment. With reference to  FIG. 9 , an automatic sensing faucet  200  comprises body  201  and water outlet  202 . The control device  100  for automatic water discharge is installed proximate the position of water outlet  202  of automatic sensing faucet  200 . The sensor unit  2  faces the sensing area of automatic sensing faucet  200 , and water discharge unit  4  faces the working area of automatic sensing faucet  200 . Power cable  9  is connected with an external power source (not shown in the drawings) through faucet body  201 . The external power source may be direct current, and it may be placed under the basin or in faucet body  201  where automatic sensing faucet is installed. Furthermore, power and the volume conditions permitting, the external power source may be a direct current power source, for example, a lithium battery, which can directly be installed at the back end of housing  1  of control device  100  for automatic water discharge or directly in housing  1 , thus is installed in water outlet  202  of faucet  200  together with the control device  100 . Therefore, there is no cable  9  which passes through faucet body  201 . Accordingly, the required parts are reduced, and installation and maintenance are made easier. 
     The control device  100  may be installed in faucet water outlet  202  by means of thread, screw, etc. Water flows to water intake chamber  14  of housing  1  from the water pipe of automatic sensing faucet  200 , then through water supplement hole  323  of diaphragm unit  32  to cavity  33  that is between diaphragm unit  32  and electromagnetic valve  31 . Furthermore, water flows from water intake channel  316  of electromagnetic valve  31  to valve core  314  of electromagnet  31 . At the initial position, electromagnetic valve  31  is shut, that is, valve core  314  of electromagnet  312  is positioned between water intake channel  316  and water leak channel  317 . Water is impeded by valve core  314  of electromagnet  312 , and can not flow to water leak channel  317  from water intake channel  316 . Meanwhile, because the water capacity in cavity  33  is certain, under the pressure of the water, diaphragm unit  32  constantly stays between water intake chamber  14  and the third holding chamber  13 . As such, water is sealed within water intake chamber  14  and electromagnetic valve assembly  3  and can not flow out through water discharge unit  4 . 
     When objects are detected in the sensing area by the sensor, for example, a user's hands are detected in the sensing area of the faucet, the processor of circuit board  21  responds to the detected signal by causing electromagnetic valve  31  to turn on. After turning on electromagnetic valve  31 , under the electromagnetic force, valve core  314  of electromagnet  312  will retract and cease blocking the connection between water intake channel  316  and water leak channel  317 . Water reaches water leak channel  317  from water intake channel  316 , and passes through small hole  325  and leak hole  15 , then enters the third holding chamber  13  and is discharged from water discharge unit  4 . Hence, the amount of water in cavity  33  is reduced. This causes the pressure to reduce on the side of diaphragm unit  32  that faces cavity  33 . Under the act of the pressure, diaphragm unit  32  moves towards cavity  33  causing diaphragm unit  32  to cease blocking water intake chamber  14  and the third holding chamber  13 . The water intake chamber  14  is connected to third holding chamber  13 , so that water directly flows into the third holding chamber  13  from water intake chamber  14 , and is discharged from water discharge unit  4 , thus achieving the automatic water discharge from automatic sensing faucet  200 . 
     When the sensor has detected the objects leaving the sensing area, for example, automatic sensing faucet  200  is no longer in use, the processor processes the detected signal to cause electromagnetic valve  31  to shut off. When the electromagnetic valve  31  is shut off, valve core  314  extends to the initial position and blocks the connection between water intake channel  316  and water leak channel  317 . At the same time, water continues to flow into cavity  33  from water supplement hole  323  of diaphragm unit  32  but can not discharge through the water leak channel  317 . Hence, the amount of water in cavity  33 , which is between diaphragm unit  32  and electromagnetic valve  31 , increases again, causing the sustained pressure of diaphragm unit  32  at the side facing the cavity  33  to be higher than at the side opposite the cavity  33 . The diaphragm unit  32  is moved away from cavity  33 . Therefore, diaphragm unit  32  again blocks the connection between water intake chamber  14  and third holding chamber  13 , causing water to be sealed in the water intake chamber  14  and electromagnetic valve assembly  3 . The water in the water intake chamber  14  can not flow into the third holding chamber  13 . As described, it automatically causes the discharge or stoppage of water from the automatic sensing faucet  200 . 
     The movement of the valve core  314  in electromagnetic valve  31  causes the water intake channel  316  and the water leak channel  317  to be connected or blocked. The movement of the diaphragm unit  32  causes the water intake chamber  14  and the third holding chamber  13  to be connected or blocked. Whether the electromagnetic valve  31  opens or shuts, it will cause the diaphragm unit  32  to move, in turn causing the third holding chamber  13  and the water intake chamber  14  to be connected or blocked. Accordingly, it achieves the discharge of water and the stopping of water discharge from unit  4 , and ultimately achieves automatic water discharge and stopping of the automatic sensing faucet  200 . 
     Control device  100  for automatic water discharge of the exemplary embodiment comprises sensor unit  2 , electromagnetic valve assembly  3 , and water discharge unit  4  which are assembled in housing  1 , making the product more compact in structure and facilitating miniaturization. When control device  100  is installed in an apparatus for automatic water discharge, such as an automatic sensing faucet  200 , it can be directly installed at the position of water outlet  202 . Assembling control device  100  into an automatic water discharge apparatus facilitates installation, simplifies structure, and reduces the necessity of installation of additional, separate components, for example, electromagnetic valve assembly and controller assembly. The apparatus for automatic water discharge including an installed control device  100  is more compact in structure, easier to be installed and more convenient to be repaired and maintained. 
     Meanwhile, electromagnetic valve assembly  3  in the control device  100  for automatic water discharge of the present invention is smaller in volume and works more efficiently. The electromagnet  312  transversely lies in the valve cover  311  of the electromagnetic valve  31  and the diaphragm unit  32  is located under electromagnetic valve  31 . The connection between water intake channel  316  and water leak channel  317  in the valve cover  311  may be blocked or unblocked by the movement of the valve core  314  of the electromagnet  312 , which is controlled by the electromagnetic valve assembly  3  being opened or shut. In the embodiment shown, the opening and shutting of electromagnetic valve assembly  3  are realized by moving the valve core  314  of electromagnet  312  a short distance. If the valve core directly acted on the diaphragm unit, the valve core would need to move a longer distance as the diaphragm unit needs to move a longer distance. That results in low efficiency of electromagnetic valve and difficulty in reducing volume. Therefore, compared to such a configuration, the exemplary embodiment of the present invention can shorten the movement distance of the valve core  314  of the electromagnet  312  and increase the efficiency of electromagnetic force, thereby enabling the electromagnet  312  to be smaller in volume and ultimately enabling the electromagnetic valve assembly  3  to be smaller in volume. According to alternate embodiments, for example if large enough space is available, control device  100  for automatic water discharge can be configured to directly drives the diaphragm unit. 
     Further, installing the sensor unit  2  and the water discharge unit  4  into the front end of housing  1 , and locating electromagnetic valve assembly  3  in the back end of housing  1  facilitates installation and manufacturing. 
     It is understood that the preceding description is given merely by way of illustration and not in limitation of the invention and that various modifications may be made thereto without departing from the spirit of the invention as claimed.