[0014] like figure 1 As shown in , the present invention includes a faucet body 1, a water inlet pipe 2 and a solenoid valve 4 arranged on the water inlet pipe, and also includes an induction joint 3 electrically connected to the faucet body, and the induction joint is fixedly arranged on the faucet through a nut 5 At the base of the body 1, and is connected with a control unit.
[0015] like figure 2 As shown in , the control unit includes a microprocessor, which controls a pulse generating circuit composed of a logic matrix to generate a pulse signal, which is sent to the induction joint after being filtered and stabilized by the circuit, and the induction joint will sense the The charge change of the faucet body is processed by the electrostatic discharge circuit (referred to as the ESD circuit) and the filter stabilization circuit, and then collected by the charge acquisition circuit and sent to the charge comparison and amplification circuit, and the amplified signal is sent to the microprocessor. In the device, the microprocessor is also connected to and controls the solenoid valve through a solenoid valve control circuit. In the present invention, the pulse generating circuit is controlled by a micro-control chip to generate pulses with a fixed frequency and a duty cycle, which is processed by the filtering and stabilizing circuit and then sent to the induction joint, so that the faucet body electrically connected to the induction joint and the surrounding An alternating electric field is generated between the objects. When the surrounding objects are relatively static, the amount of charge collected by the filter stabilization circuit and the charge collection circuit is fixed. When there is a human body, especially a human hand, because the liquid in the human body accounts for 70%, the human body itself has a certain amount of charge. When the human hand approaches the faucet body, a part of the charge on it will be absorbed by the surface of the faucet body. At this time, after the inductive joint collects this charge change, the filter stabilization circuit and the charge collection circuit are compared by the charge comparison and comparison circuit. The amplifying circuit is sent to the microprocessor, and the digital-to-analog conversion circuit in the microprocessor is converted and compared with the threshold value, and if it is higher than the threshold value, the solenoid valve control circuit controls the solenoid valve to open. , so that the faucet comes out of water, if it is lower than the threshold value, no treatment will be done. At the same time, because water is also a weak conductor, when the solenoid valve is opened, the flow of water makes the electric charge of the faucet change constantly. Therefore, the electric charge collection circuit should constantly track the changes of the environment under the control of the microprocessor, and continuously Change the threshold value of boiling water and shutting water, completely automatic and stable.
[0016] The microprocessor and peripheral circuits form the control part to control the work of each part of the circuit unit, such as Figure 4 As shown in , the environmental changes can be automatically tracked by the inductive emission control unit and the tracking control unit, so as to control the pulse generation circuit to work, and the charge comparison and amplification circuit converts the amplified signal by the analog-to-digital conversion unit and sends it to the induction The receiving control unit sets the threshold value through the induction receiving control unit, controls the signal discriminating unit to control the work of the water switch unit, controls the solenoid valve control circuit to realize the switch water, and can also use the battery detection and alarm unit to detect the battery When the battery voltage is lowered to the point that it cannot work normally, an alarm prompt is issued. The button detection unit detects the buttons externally connected to the microprocessor for adjusting the sensing distance and resetting the program, so as to realize further control. In order to work stably, the microprocessor adopts a watchdog circuit, which ensures the reliable operation of the program. The specific programs of each unit in the microprocessor can be compiled according to specific functional requirements without creative work by those of ordinary skill in the art, which will not be repeated here.
[0017] The control unit is also connected with a power supply circuit, which realizes the power supply of the entire control unit, and can use four AA batteries. In order to save energy, it adopts the sleep mode to work, and the quiescent current is less than 20uA.
[0018] When the solenoid valve adopts a pulse type solenoid valve, the solenoid valve control circuit is as follows: image 3 As shown in the figure, it includes two pulse input circuits with the same structure. Taking one of them as an example, the control input terminal (ie the forward drive signal terminal) sent from the microcontroller simultaneously controls the pulse drive F1 circuit and the pulse drive F2 , in which F1 is conducting forward, F2 is grounded, and the output ends of the two drive circuits are connected to both ends of the solenoid valve; similarly, the other control input end of the microcontroller (ie, the reverse drive signal end) simultaneously controls the pulse drive Circuit F2 and pulse drive F1, in which F2 is conducting in the forward direction, F1 is grounded, and the output ends of the two drive circuits are connected to both ends of the solenoid valve. Due to the use of a pulse solenoid valve, only two states are required to switch between on and off states. Pulse, namely forward pulse and reverse pulse, the width of the pulse is only tens of milliseconds, so that the pulse current flowing through the solenoid valve controls the forward or reverse conduction of the solenoid valve, thereby controlling the switch of the solenoid valve, so there is no need to maintain the current, Therefore, the purpose of energy saving can be achieved, and the energy consumption of the battery can be saved.
[0019] The capacitive sensing faucet provided by the present invention has been introduced in detail above. The principles and implementations of the present invention are described with specific examples in this paper. The descriptions of the above embodiments are only used to help understand the method and the core of the present invention. At the same time, for those of ordinary skill in the art, according to the idea of the present invention, there will be changes in the specific implementation and application scope. To sum up, the content of this specification should not be construed as a limitation of the present invention.
