Adjustable light parameter device applied to optical water quality detection equipment

Abstract

The utility model discloses a kind of adjustable light parameter devices applied to optical water quality detection equipment, it is related to water quality detection technical field, including light emitting unit, photosensitive unit and conversion module, it is characterized by: still including main control module and the driving module of adjustable output current size, cooperate light emitting unit, photosensitive unit and conversion module composition adjustable light module;The main control module includes at least one control output pin A used as current parameter adjustment instruction output and one closed loop sampling pin F, the driving module is electrically connected to the control output pin A of main control module and has a current output pin C used as output current, the light emitting unit includes light emitting diode and light emitting diode is electrically connected to the current output pin C of driving module, the photosensitive unit is electrically connected to conversion module, and the closed loop sampling pin F of main control module is electrically connected to conversion module.This application has the effect of improving the measurement stability and product consistency of water quality parameter detection equipment.

Description

Technical Field

[0001] This application relates to the field of water quality testing technology, and in particular to an adjustable light parameter device for use in optical water quality testing equipment. Background Technology

[0002] In water quality parameter detection, optical sensors primarily measure turbidity using transmission and scattering methods. These sensors typically consist of a core detection unit comprised of a light-emitting diode (LED) and a photodiode (photodetector). Their working principle is as follows: when energized, the LED emits a beam of light of a specific wavelength. When this light passes through the water sample, suspended particles cause light intensity attenuation (change in transmitted light intensity) or scattering (change in scattered light intensity). The photodiode receives the transmitted or scattered light passing through the water and converts the optical signal into a corresponding electrical signal. The change in its output electrical parameters (such as current, voltage, or resistance) is quantitatively related to the turbidity of the water. For example, in turbidity detection, a higher concentration of suspended matter in the water sample leads to a more significant scattering / absorption of incident light, resulting in a corresponding change in the light intensity received by the photodetector. Finally, the turbidity value is obtained through photoelectric conversion and signal processing.

[0003] It is currently known that the luminous intensity of a light-emitting diode (LED) is related to the magnitude of the current input to the LED. Within a reasonable range, the greater the current input to the LED, the stronger the luminous intensity of the LED, and vice versa.

[0004] However, diodes in current sensors generally have the following shortcomings: 1) After mass production, due to assembly process and component errors, the current of the input diode of the sensor composed of the same batch of components is inconsistent, which means that the light intensity received by the sensor is inconsistent in the same environment. 2) The current input to the LED is constant, and the light intensity of the LED will decrease after long-term use.

[0005] Both of the above factors result in poor performance stability and consistency of water quality parameter testing equipment. Therefore, this application proposes a new technical solution. Utility Model Content

[0006] To improve the measurement stability and product consistency of water quality parameter detection equipment, this application provides an adjustable optical parameter device for use in optical water quality detection equipment.

[0007] This application provides an adjustable optical parameter device for optical water quality testing equipment, which adopts the following technical solution: A device for adjusting optical parameters in optical water quality testing equipment includes a light-emitting unit, a photosensitive unit, and a conversion module. Its features include a main control module and a drive module with adjustable output current, which, together with the light-emitting unit, photosensitive unit, and conversion module, form an adjustable optical module. The main control module includes at least one control output pin A used for current parameter adjustment command output and a closed-loop sampling pin F. The driving module is electrically connected to the control output pin A of the main control module and has a current output pin C used for output current. The light-emitting unit includes a light-emitting diode and the light-emitting diode is electrically connected to the current output pin C of the driving module. The photosensitive unit is electrically connected to the conversion module. The closed-loop sampling pin F of the main control module is electrically connected to the conversion module.

[0008] Optionally, the main control module includes a control unit, a PWM output module, and an ADC voltage sampling module, wherein the control unit is electrically connected to the PWM output module and the ADC voltage sampling module; The signal output terminal of the PWM output module serves as control output pin A, and control output pin A is electrically connected to the drive module. The sampling terminal of the ADC voltage sampling module is used as the closed-loop sampling pin F, and the closed-loop sampling pin F is electrically connected to the conversion module. The drive module includes a linear constant current drive circuit, which has a PWM input pin B, and the PWM input pin B is electrically connected to the control output pin A.

[0009] Optionally, the conversion module includes an operational amplifier and a feedback resistor Rf, one end of which is connected to the inverting input terminal of the operational amplifier and the other end is connected to the output terminal of the operational amplifier. The inverting input of the operational amplifier is used as pin D, the output of the operational amplifier is used as pin E, pin D is electrically connected to the photosensitive unit, pin E is electrically connected to the closed-loop sampling pin F, and the non-inverting input of the operational amplifier is grounded.

[0010] Optionally, the light-emitting unit includes: Multiple light-emitting diodes, each with different parameters; The adjustment module includes a contact that is connected to any one of the light-emitting diodes and an adjustment contact that is used to output an adjustment signal, the contact being electrically connected to the drive module; The switching circuit has its input side electrically connected to the adjustment contact of the adjustment module, and its output side includes an on / off pin for switching the path between the main control module and the conversion module and a voltage adjustment pin, wherein the on / off pin is connected in series between the main control module and the conversion module. The voltage regulation circuit has its input side electrically connected to the voltage regulation pin of the switching circuit, and its output side electrically connected to the main control module.

[0011] Optionally, the adjustment module includes an assembly block and a fixed disk. The assembly block has a through slot for accommodating multiple light-emitting diodes (LEDs). The pins of each LED are electrically connected to multiple sets of movable contacts preset at the bottom of the assembly block. The assembly block is rotatably connected to the fixed disk, which is fixedly connected to the control main board. The fixed disk is hollow inside and has an opening at one end facing the assembly block. A spring is provided inside the fixed disk, and a contact plate is fixedly connected to the spring. A set of conductive contacts is provided on the contact plate for contacting any set of movable contacts. An adjustment contact is provided on the contact plate, and a fixed contact corresponding to the adjustment contact is provided at the bottom of the assembly block.

[0012] Optionally, the switching circuit includes: Transistor Q has its base connected to the signal input terminal and its emitter grounded; A current-limiting resistor R1 is connected in series between the base of transistor Q and the signal input terminal; Pull-down resistor R2 has one end connected to the junction of the base of transistor Q and the current-limiting resistor R1, and the other end connected to the emitter of transistor Q. The relay KA has one end of its coil connected to the collector of transistor Q, and the other end of the coil connected in series with the regulating contact. The normally closed contact K1 is used as the on / off pin and is connected in series between the main control module and the conversion module. The normally open contact K2 is used as the voltage regulating pin and is connected in series with the voltage regulating circuit. The freewheeling diode D1 has its anode connected to the junction of the relay coil and the collector of the transistor Q, and its cathode connected to the junction of the relay coil and the regulating contact.

[0013] Optionally, the voltage regulating circuit includes: Inductor L is connected in series with normally open contact K2; Diode D2 has its negative terminal connected between inductor L and normally open contact K2, and its positive terminal connected to the positive terminal of the main control module. Capacitor C has one end connected to the connection point between the positive terminal of diode D2 and the positive terminal of the main control module, and the other end grounded.

[0014] In summary, this application includes the following beneficial technical effects: the main control module adjusts the light intensity of the LED by adjusting the current input to the LED from the drive module. When the photodiode receives light from the LED, it converts the light signal into a current signal, and then converts the current signal into a voltage signal through a conversion circuit, which is fed back to the main control module. The main control module adjusts the signal input to the drive module based on the feedback voltage signal, forming a control feedback module, thereby realizing the LED brightness adjustment function, thus eliminating errors caused by LED manufacturing process errors, assembly errors, and light intensity attenuation caused by long-term use. Attached Figure Description

[0015] Figure 1 This is a module structure diagram of an embodiment of this application.

[0016] Figure 2 This is a structural diagram of the conversion circuit according to an embodiment of this application.

[0017] Figure 3 This is a schematic diagram of the structure of the adjustment module in an embodiment of this application.

[0018] Figure 4 This is an example diagram of the contact points between the assembly block and the contact plate in an embodiment of this application.

[0019] Figure 5 This is a schematic diagram of the switching circuit structure according to an embodiment of this application.

[0020] Figure 6 This is a schematic diagram of the voltage regulation circuit structure according to an embodiment of this application. Explanation of reference numerals in the attached drawings: 1. Assembly block; 2. Fixing plate; 3. Through slot; 4. Spring; 5. Contact plate. Detailed Implementation

[0021] The following is in conjunction with the appendix Figure 1-6 This application will be described in further detail.

[0022] This application discloses an adjustable light parameter device for use in optical water quality testing equipment.

[0023] Reference Figure 1 The adjustable light parameter device used in optical water quality testing equipment includes a light-emitting unit, a photosensitive unit, a conversion module, a main control module, and a drive module with adjustable output current, forming an adjustable light module.

[0024] In this embodiment, the main control module includes a control output pin A used for outputting current parameter adjustment commands and a closed-loop sampling pin F. The drive module is electrically connected to the control output pin A of the main control module and has a current output pin C used for outputting current.

[0025] The light-emitting unit includes a light-emitting diode (LED), which is electrically connected to the current output pin C of the driving module. The photosensitive unit includes a photodiode, which is electrically connected to the conversion module. The closed-loop sampling pin F of the main control module is electrically connected to the conversion module.

[0026] With the above settings, the main control module controls the current input to the LED by the drive module, thereby controlling the LED's luminous intensity. When the photodiode receives light from the LED, it converts the light signal into a current signal, which is then converted into a voltage signal by a conversion circuit and fed back to the main control module. Based on the feedback voltage signal, the main control module adjusts the signal input to the drive module, forming a control feedback module. This enables the LED brightness adjustment function, improving the measurement stability and product consistency of the water quality parameter detection equipment.

[0027] The main control module (main control chip) includes a control unit, a PWM output module, and an ADC voltage sampling module. The control unit is electrically connected to the PWM output module and the ADC voltage sampling module. In this embodiment, the control unit can use an MCU to control and process the PWM output and ADC sampling.

[0028] The PWM output module can use a timer, external resistors and capacitors to form a multivibrator to generate a rectangular wave output. Then, a comparator compares the timer count value with a preset duty cycle value to generate a corresponding PWM signal. The output driver circuit then converts the digital PWM signal generated by the comparator into a suitable analog signal and outputs it to the control output pin A, which is electrically connected to the driver module.

[0029] The ADC voltage sampling module can be a sampling circuit that samples an analog voltage signal, a quantizer that converts the analog voltage signal output by the sampling circuit into a discrete digital signal, an encoder that encodes the quantized digital signal, and a control logic circuit that coordinates the operation of each sub-module. The sampling terminal of the ADC voltage sampling module is used as a closed-loop sampling pin F, which is electrically connected to the output terminal of the conversion module.

[0030] The driving module includes a linear constant current driving circuit, which has a PWM input pin B. The PWM input pin B is electrically connected to the control output pin A. In this embodiment, the linear constant current driving circuit uses a prior art linear constant current LED driver chip, such as the LM3409 chip. The chip's peripheral circuit is set according to the chip's datasheet. Since the design of the chip and its peripheral circuit is prior art, it will not be described in detail here. This enables the linear constant current driving circuit to change the current output from pin C according to the duty cycle of the PWM signal at input pin B.

[0031] It should be noted that the control unit, PWM output module, ADC voltage sampling module and linear constant current drive circuit in the above main control module can all be implemented using existing technologies, and those skilled in the art can refer to them for design.

[0032] Reference Figure 2 In this embodiment, the conversion module includes an I / V conversion circuit, which includes an operational amplifier and a feedback resistor Rf. One end of the feedback resistor Rf is connected to the inverting input terminal of the operational amplifier, and the other end is connected to the output terminal of the operational amplifier. The inverting input terminal of the operational amplifier is used as pin D, and the output terminal of the operational amplifier is used as pin E. Pin D is electrically connected to a photodiode, and pin E is electrically connected to the closed-loop sampling pin F. The non-inverting input terminal of the operational amplifier is grounded.

[0033] With the above settings, after the photodiode receives the light signal, it converts the light signal into a current signal and sends it to pin D. After the operational amplifier receives the current signal, it processes the current signal into a voltage signal and outputs it to pin F of the main control module through pin E.

[0034] Therefore, the work status process is described as follows: 1. Controlling LED illumination: When the sensor system is powered on and starts working, the main control chip outputs a PWM signal waveform through pin A to pin B of the linear constant current LED driver chip. After receiving the PWM signal, the chip starts to output current to the LED through pin C, causing the LED to change from off to on.

[0035] 2. Adjusting the LED's luminous intensity: When the LED is in the luminous state, the photodiode receives the light signal from the LED and converts it into a current signal, which is then output to the I / V conversion circuit. The I / V conversion circuit converts the input current signal into a voltage signal and outputs it to the main control chip. The main control chip adjusts the output PWM (adjustable duty cycle signal) according to the input voltage signal, thereby controlling the current output from the linear constant current LED driver chip to the LED, ultimately controlling the LED's brightness.

[0036] In another embodiment of this application, considering that different parameters of light-emitting diodes (LEDs) are needed to ensure detection accuracy when detecting water quality with different turbidity levels, for example, when detecting high turbidity water quality, LEDs with higher light intensity are needed to ensure sufficient light penetration, this application provides multiple LEDs. A suitable LED can be selected for detection based on the detection conditions. Furthermore, considering that the main control module in the above embodiment adjusts the current input to the LED based on the voltage feedback from the photosensitive unit, to prevent the main control module from reverting to the current required for the initial LED after switching to a different LED (other than the one initially used), it is necessary to disconnect the feedback voltage from the conversion circuit to the main control module when switching to a different LED, and simultaneously provide the main control module with the voltage required for the initial LED use, so that the main control module does not revert to the original current.

[0037] Based on the above approach, the specific settings are as follows: The light-emitting unit includes multiple light-emitting diodes with different parameters, an adjustment module, a switching circuit, and a voltage regulation circuit; among them, the parameter of the light-emitting diode refers to the maximum luminous intensity.

[0038] Reference Figure 3 and Figure 4 The adjustment module includes a set of conducting contacts that are connected to any one of the light-emitting diodes and an adjustment contact used as an output adjustment signal. The conducting contacts are electrically connected to the drive module, and the adjustment contacts are electrically connected to the input side of the switching circuit. The output side of the switching circuit includes an on / off pin for switching the path between the main control module and the conversion module and a voltage adjustment pin. The on / off pin is connected in series between the main control module and the conversion module. The voltage adjustment pin is electrically connected to the input side of the voltage adjustment circuit, and the output side of the voltage adjustment circuit is electrically connected to the main control module.

[0039] With the above settings, when the LED is switched by adjusting the module, the adjustment contact triggers the switching circuit, which disconnects the path between the main control module and the conversion module by the switching circuit's on / off pin. At the same time, the voltage adjustment pin connects to the voltage adjustment circuit, which provides the main control module with the voltage value of the LED when it is used for the first time.

[0040] Reference Figure 3 and Figure 4 In another embodiment of this application, the adjustment module includes a cylindrical assembly block 1 and a fixed disk 2. The assembly block 1 has a through slot 3 for accommodating the pins of multiple light-emitting diodes (LEDs). The pins of each LED are soldered to multiple sets of movable contacts (each set includes one positive contact and one negative contact) pre-set on the bottom of the assembly block 1. The multiple sets of movable contacts are evenly distributed around the circumference of the assembly block 1. Figure 4As shown in the example, the LED beads are extended out of the through slot 3.

[0041] The bottom of the fixed disk 2 is fixed to the control main board (the circuit board integrated with the components of this device) by screws. The assembly block 1 is rotatably connected to the upper end of the fixed disk 2. The fixed disk 2 is hollow inside and has an opening at the top. A spring 4 is fixed inside the fixed disk 2, and a contact plate 5 parallel to the assembly block 1 is fixed to the spring 4. There are two sets of conductive contacts symmetrically arranged circumferentially on the contact plate 5. They can contact any set of moving contacts, thereby enabling conduction with any LED, allowing the LED to be connected to the drive module circuit.

[0042] In order to trigger the switching circuit when the assembly block 1 is rotated, the adjustment contact is set on the contact plate 5. The bottom of the assembly block 1 is provided with a fixed contact that cooperates with the adjustment contact. When the first LED (which can be considered as the first gear) is connected to the circuit, the adjustment contact is in contact with the fixed contact, and the switching circuit is not triggered. Once the assembly block 1 is rotated to switch to another gear of LED, the adjustment contact is disconnected from the fixed contact, and the switching circuit is triggered.

[0043] Reference Figure 5 In another embodiment of this application, the switching circuit includes: Transistor Q has its base connected to the signal input terminal and its emitter grounded; A current-limiting resistor R1 is connected in series between the base of transistor Q and the signal input terminal; Pull-down resistor R2 has one end connected to the junction of the base of transistor Q and the current-limiting resistor R1, and the other end connected to the emitter of transistor Q. The relay KA has one end of its coil connected to the collector of transistor Q, and the other end of the coil connected in series with the wire connected to the regulating contact. The normally closed contact K1 is used as the on / off pin and is connected in series between the main control module and the conversion module. The normally open contact K2 is used as the voltage regulating pin and is connected in series with the voltage regulating circuit. The freewheeling diode D1 has its anode connected to the junction of the relay coil and the collector of the transistor Q, and its cathode connected to the junction of the relay coil and the regulating contact.

[0044] With the above settings, when the LED is replaced, the regulating contact is opened, the relay coil is de-energized, the normally closed contact K1 is opened, thus disconnecting the path between the main control module and the conversion module, and the normally open contact K2 is closed, thus turning on the voltage regulation circuit.

[0045] Reference Figure 6 In another embodiment of this application, the voltage regulating circuit includes: Inductor L is connected in series with normally open contact K2; Diode D2 has its negative terminal connected between inductor L and normally open contact K2, and its positive terminal connected to the positive terminal of the main control module. Capacitor C has one end connected to the connection point between the positive terminal of diode D2 and the positive terminal of the main control module, and the other end grounded.

[0046] With the above settings, the voltage regulation circuit is turned on to provide the main control module with the original voltage value (i.e., the voltage value of the LED when it is used for the first time). The specific component parameters are selected according to actual needs.

[0047] The above are all preferred embodiments of this application, and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.

Claims

1. A device for adjusting optical parameters in optical water quality testing equipment, comprising a light-emitting unit, a photosensitive unit, and a conversion module, characterized in that: It also includes a main control module and a drive module with adjustable output current, which together with the light-emitting unit, photosensitive unit and conversion module form an adjustable light module; The main control module includes at least one control output pin A used for current parameter adjustment command output and a closed-loop sampling pin F. The driving module is electrically connected to the control output pin A of the main control module and has a current output pin C used for output current. The light-emitting unit includes a light-emitting diode and the light-emitting diode is electrically connected to the current output pin C of the driving module. The photosensitive unit is electrically connected to the conversion module. The closed-loop sampling pin F of the main control module is electrically connected to the conversion module.

2. The adjustable optical parameter device for optical water quality testing equipment according to claim 1, characterized in that: The main control module includes a control unit, a PWM output module, and an ADC voltage sampling module. The control unit is electrically connected to the PWM output module and the ADC voltage sampling module. The signal output terminal of the PWM output module serves as control output pin A, and control output pin A is electrically connected to the drive module. The sampling terminal of the ADC voltage sampling module is used as the closed-loop sampling pin F, and the closed-loop sampling pin F is electrically connected to the conversion module. The drive module includes a linear constant current drive circuit, which has a PWM input pin B, and the PWM input pin B is electrically connected to the control output pin A.

3. The adjustable optical parameter device for optical water quality testing equipment according to claim 1, characterized in that: The conversion module includes an operational amplifier and a feedback resistor Rf. One end of the feedback resistor Rf is connected to the inverting input terminal of the operational amplifier, and the other end is connected to the output terminal of the operational amplifier. The inverting input of the operational amplifier is used as pin D, the output of the operational amplifier is used as pin E, pin D is electrically connected to the photosensitive unit, pin E is electrically connected to the closed-loop sampling pin F, and the non-inverting input of the operational amplifier is grounded.

4. The adjustable optical parameter device for optical water quality testing equipment according to claim 1, characterized in that, The light-emitting unit includes: Multiple light-emitting diodes, each with different parameters; The adjustment module includes a contact that is connected to any one of the light-emitting diodes and an adjustment contact that is used to output an adjustment signal, the contact being electrically connected to the drive module; The switching circuit has its input side electrically connected to the adjustment contact of the adjustment module, and its output side includes an on / off pin for switching the path between the main control module and the conversion module and a voltage adjustment pin, wherein the on / off pin is connected in series between the main control module and the conversion module. The voltage regulation circuit has its input side electrically connected to the voltage regulation pin of the switching circuit, and its output side electrically connected to the main control module.

5. The adjustable optical parameter device for optical water quality testing equipment according to claim 4, characterized in that: The adjustment module includes an assembly block (1) and a fixed disk (2). The assembly block (1) has a through slot (3) for accommodating multiple light-emitting diodes. The pins of each light-emitting diode are electrically connected to multiple sets of moving contacts preset at the bottom of the assembly block (1). The assembly block (1) is rotatably connected to the fixed disk (2). The fixed disk (2) is fixedly connected to the control main board. The fixed disk (2) is hollow inside and has an opening at one end facing the assembly block (1). The fixed disk (2) is provided with a spring (4). The spring (4) is fixedly connected to a contact plate (5). The conductive contacts are a set and are set on the contact plate (5) for contacting any set of moving contacts. The adjustment contacts are set on the contact plate (5). The bottom of the assembly block (1) is provided with fixed contacts corresponding to the adjustment contacts.

6. The adjustable optical parameter device for optical water quality testing equipment according to claim 5, characterized in that, The switching circuit includes: Transistor Q has its base connected to the signal input terminal and its emitter grounded; A current-limiting resistor R1 is connected in series between the base of transistor Q and the signal input terminal; Pull-down resistor R2 has one end connected to the junction of the base of transistor Q and the current-limiting resistor R1, and the other end connected to the emitter of transistor Q. The relay KA has one end of its coil connected to the collector of transistor Q, and the other end of the coil connected in series with the regulating contact. The normally closed contact K1 is used as the on / off pin and is connected in series between the main control module and the conversion module. The normally open contact K2 is used as the voltage regulating pin and is connected in series with the voltage regulating circuit. The freewheeling diode D1 has its anode connected to the junction of the relay coil and the collector of the transistor Q, and its cathode connected to the junction of the relay coil and the regulating contact.

7. The adjustable optical parameter device for optical water quality testing equipment according to claim 6, characterized in that, The voltage regulation circuit includes: Inductor L is connected in series with normally open contact K2; Diode D2 has its negative terminal connected between inductor L and normally open contact K2, and its positive terminal connected to the positive terminal of the main control module. Capacitor C has one end connected to the connection point between the positive terminal of diode D2 and the positive terminal of the main control module, and the other end grounded.

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