JP3221189U - Detection circuit of essential oil measuring device - Google Patents

Abstract

An object of the present invention is to provide a low cost, small volume and high accuracy detection circuit of an essential oil measuring device. A detection circuit of an essential oil weighing device includes an MCU connected to a connector of a next stage device via a serial data pin, and an LED pin of the MCU is connected to two serially connected luminous tubes L1 and L2. The MCU has a plurality of ADC pins ADC1 and ADC2, and any one ADC pin ADC1 (ADC2) is connected to one photo tube LD1 (LD2) via one operational amplifier U3 (U4) Then, signal collection is performed on the light receiving tube LD1 (LD2). This can realize the automation control of the essential oil dose measurement only by the signal analysis of the light emitting tube-light receiving tube pair by the MCU and the control of the connector of the next stage device by the MCU, the design cost of the whole circuit is low, and the volume is Small, high detection accuracy. [Selected figure] Figure 2

Description

  The present invention relates to the field of electronic circuits, and more particularly to a detection circuit of an essential oil measuring device.

  In the case of essential oil aromatherapy, especially in complex aromatherapy, as a conventional method of pouring essential oils, small holes are provided in the stopper of the essential oil bottle, and when pouring the essential oil, the essential oil bottle is manually tilted to drop the essential oil in drops from the small holes. Allow quantitative control of the essential oil dose by letting it drain and manually counting the number of drops of essential oil, and when the desired number of drops is reached, manually return the essential oil bottle to an upright position and stop the essential oil dripping There is.

  Such a conventional quantitative control method based on a combination of manual operation and visual inspection by people is not suitable for the demand for product performance and the change of generation of products which are becoming increasingly smart today. Not only that, but also in terms of accuracy, it is not possible to operate so precisely, which requires a large amount of human or material resources.

  With the development of society and advances in science and technology, people are seeking automatic control, automatic weighing, low manufacturing costs, and intelligent development of products for quantitative control of essential oils. However, under the pressure of demand for low cost, precisely controlling the dose and proportion of the essential oil has become a difficult problem to solve, and some of the current low-grade aromatherapy machines for private use There is no low-cost, high-precision weighing device.

  In light of the above, conventional essential oil metering systems and devices require further improvement in order to be characterized by low cost, small volume and high accuracy. Above all, since the detection circuit of the essential oil measuring device is an important part of the whole measuring device, improvement of the detecting circuit of the conventional essential oil measuring device is the most important issue.

  The present invention provides a low cost, small volume and high precision oil sensing device detection circuit to solve the above-mentioned technical problems.

  The technical means adopted by the present invention in order to realize the above object are as follows.

  A detection circuit of an essential oil measuring device, comprising: an MCU connected to a connector of a next stage device via a serial data pin, wherein the LED pin of the MCU is connected to two serially connected luminous tubes, The MCU has a plurality of ADC pins, and any one ADC pin is connected to one phototube through one operational amplifier to perform signal collection to the phototube.

  Preferably, the power supply circuit further includes a power supply circuit connected respectively to the MCU and the connector to supply power directly to the MCU and the connector and indirectly to an electronic device connected to the MCU.

  Preferably, the power supply circuit includes a regulator U2 and a capacitor C2 connected in series, the regulator U2 is connected to the VCC pin of the MCU, and the other end of the C2 is connected to the V + pin of the connector .

  Preferably, the serial data pins of the MCU include one serial data output pin DO1 and one serial data output pin DI1, and the DO1 and DI1 pins of the MCU are correspondingly connected to the DO1 and DI1 pins of the connector, respectively. There is.

  Preferably, the serial data pins of the MCU include two serial data output pins DO1, DO2 and one serial data output pin DI1, the DO1, DO2 and DI1 pins of the MCU correspond to the connectors DO1, DO2 and DI1, respectively. Corresponding to the pin is connected.

  Preferably, there are two ADC pins, and the two pins are ADC1 and ADC2, respectively, the ADC1 pin is connected to the photo tube LD1 through the operational amplifier U3, and the ADC2 pin is received through the operational amplifier U4. It is connected to the tube LD2.

  Preferably, one current limiting resistor R1 is connected between the LED pin and the two serially connected arc tubes.

  Preferably, the chip model number of the MCU is HT48R005.

  The beneficial technical effects of the present invention are as follows. That is, the present invention can realize the automation control of the essential oil dose measurement only by the signal analysis of the luminous tube-photosensitive tube pair by the MCU and the control of the connector of the next stage device by the MCU, and the design cost of the whole circuit is low. , Volume is small, detection accuracy is high.

FIG. 1 is a structural schematic view of an essential oil measuring device according to the present invention. FIG. 2 is a circuit diagram of the detection circuit of the essential oil measuring device according to the present invention.

  In order to make the purpose, technical means and advantages of the present invention clearer, the present invention will be described in more detail with reference to the following examples, but the protection scope of the present invention is limited to the following specific examples. I will not.

  FIG. 1 is a structural schematic view of an essential oil measuring device. The entire apparatus includes at least two pairs of light emitting tube 1, light receiving tube 2, oil feeding tube 3 and detection circuit board 4.

  The light emitting tube 1 and the light receiving tube 2 are distributed on both sides of the oil feeding tube 3, and the light beam emitted by the light emitting tube 1 passes through the oil feeding tube wall → essential oil in the tube or air → through the other wall of the oil feeding tube , And finally hit the light receiving tube 2. Under the premise that the intensity of the light emitted by the arc tube is constant, if the essential oil does not flow in the oil feeding tube 3, the intensity of the light beam arriving at the attachment tube 2 also becomes constant, and the essential oil in the oil feeding tube 3 Is blocked and scattered by the essential oil, and the intensity of the light arriving at the junction tube 2 drops.

  At least two pairs of light emitting tubes 1 and light receiving tubes 2 are welded onto the detection circuit board 4, and the oil feeding tube 3 is positioned between the light emitting tube 1 and the light receiving tube 2 by a restraint mechanism (not shown) It secures an essential oil passage through which the emitted light passes in the oil feed pipe 3. The detection circuit board 4 supplies a stable current to the light emitting tube 1 to emit a light beam having a constant brightness. On the other hand, when the light receiving tube 2 receives a light beam from the light emitting tube 1, the electrical characteristics thereof change according to the intensity of the received light beam, and an electrical signal is input to the detection circuit board 4. When the circuit on the detection circuit board 4 amplifies and filters the degree of change in the electrical characteristics of the light receiving pipe 2, an electric signal having a negative correlation with the essential oil of the oil feeding pipe 3 is formed. After comparison with a reference electrical signal preset in the circuit of (4), the switching amount signal is output.

  As described above, after each pair of light emitting tube-light receiving tube is analyzed by the circuit on the detection circuit board 4, a single switching amount signal for the device in which the next-stage essential oil dose is controlled is output.

  The next stage device can realize accurate metering and control of the essential oil in the following procedure, when adopting the device according to the present invention to control and meter the essential oil dose.

  In the first step, the pump for pumping the essential oil is controlled to suck back, and the essential oil in the oil feeding pipe 3 is sucked back for a predetermined period to send the essential oil in the oil feeding pipe 3 back into the essential oil bottle. The individual output signal of is returned to the "out of oil" signal state. As an adaptive function of the device according to the present application, the device according to the present application automatically adjusts the reference electric signal level to be compared with reference to the electric characteristics of the light receiving tube 2 in the “essential oil exhaustion” state. The purpose is to detect external light interference, deterioration of oil transmission pipe, oil film of essential oil remaining in oil transmission pipe, deterioration of luminous tube 1, deterioration of light receiving pipe 2, difference in kind of essential oil, etc. It is to prevent drift and dynamically adjust the reference electrical signal in real time, which can improve the detection accuracy, adaptability of the device according to the present application.

  In the second step, the pump for delivering the essential oil is controlled to deliver the essential oil in the positive direction, and when the essential oil passes through the first pair of light emitting tube-light receiving tube pair, the switching signal at which the first output is detected is used. The transition is made, and the transition time point t1 is stored.

  In the third step, the pump for delivering the essential oil is subsequently controlled to deliver the essential oil in the positive direction, and when the essential oil passes through the second pair of light emitting tube-light receiving tube pair, the opening / closing amount at which the second output is detected Transition the signal and store the transition time t2.

  In the fourth step, at t2-t1, the time difference between the essential oil passing through the two pairs of light emitting tube and light receiving tube is calculated, and the flow rate of the essential oil in the oil feeding pipe 3 is obtained. By multiplying the area, it is possible to obtain the volume of essential oil that has flowed through the oil supply pipe 3 per unit time as the volume velocity. By dividing this volume speed from the target essential oil volume that needs to be pumped this time, it is possible to obtain the time t at which the oil pump needs to pump the essential oil in the positive direction.

  In the fifth step, the pump for delivering the essential oil is continuously controlled to deliver the essential oil in the positive direction, and is stopped when continuing until time t. At this point, the quantitative feed of this time is completed.

  In the sixth step, the pump for pumping the essential oil is controlled to suck back, and the essential oil in the oil feeding pipe 3 is suckbacked for a predetermined period until the two open / close outputs both return to the signal state of "out of essential oil". Do. The purpose of this step is primarily due to the essential oil in the pipe 3 being dissipated along the air from the end of the pipe by sending the essential oil in the pipe 3 back into the bottle in suckback. And to prevent the influence of the accuracy of the lomatherapy. Second, by separating the essential oil from the oil supply pipe 3 as much as possible, it prevents corrosion and deterioration of the oil supply pipe 3 due to long-time contact with the essential oil.

  In principle, as long as only two pairs of luminous tube-photosensitive tube pairs, the function of metering and controlling the essential oil dose can be achieved. If several light emitting tube-light receiving tube pairs and their output switching amount signals are added, the next-stage device compensates for the fluctuation due to the fluctuation of the rotational speed of the oil feed pump and the wear of the oil feed pump. The essential oil delivery rate can be more accurately analyzed to maintain detection and control accuracy.

  The detection circuit board 4 is provided with a detection circuit for detecting and controlling the essential oil.

  Specifically, as shown in FIG. 2, the detection circuit of the essential oil measuring device includes an MCU connected to the connector of the next stage device through the serial data pin. The MCU transmits and receives signals to and from the connector of the next-stage device through serial data pins. The LED pins of the MCU are connected to two serially connected luminous tubes L1 and L2. The MCU has a plurality of ADC pins, and any one ADC pin is connected to one phototube through one operational amplifier to perform signal collection to the phototube. As can be seen from the above, the light emitting tube 1 and the light receiving tube 2 are distributed on both sides of the oil feeding tube 3. Under the premise that the intensity of the light emitted by the arc tube is constant, if the essential oil does not flow in the oil feeding tube 3, the intensity of the light beam arriving at the attachment tube 2 also becomes constant, and the essential oil in the oil feeding tube 3 Is blocked and scattered by the essential oil, and the intensity of the light arriving at the junction tube 2 drops. This is the basis for the MCU through this circuit theory.

  The detection circuit further includes a power supply circuit connected to the MCU and the connector to supply power directly to the MCU and the connector and indirectly to an electronic device connected to the MCU. The power supply circuit includes a regulator U2 and a capacitor C2 connected in series. The regulator U2 is connected to the VCC pin of the MCU, and the other end of the C2 is connected to the V + pin of the connector.

  Specifically, in the present embodiment, the serial data pins of the MCU include two serial data output pins DO1 and DO2 and one serial data output pin DI1. The DO1, DO2 and DI1 pins of the MCU are correspondingly connected to the DO1, DO2 and DI1 pins of the connector, respectively. Of course, using a single DO by combining the two signal lines DO1 and DO2, the regulator U2 detects that the essential oil passes through the area of the first pair of light emitting tube-light receiving tube, DO When the first short pulse is output to the signal line and it is detected that the essential oil passes through the area of the second pair of light emitting tube-light receiving tube pair, the second short pulse is output to the DO signal line. The next stage device may count the time points of two pulses before and after on the DO signal line, and in such a case, the purpose of weighing can be achieved. By omitting one signal line, U2 can use a smaller microcontroller core piece, which is advantageous for further cost reduction.

  Two ADC pins are provided. The two pins are ADC1 and ADC2, respectively. The ADC1 pin is connected to the light receiving tube LD1 via an operational amplifier U3. The ADC2 pin is connected to the light receiving tube LD2 via an operational amplifier U4. A resistor R1 is connected between the LED pin and the two series arc tubes. R1 is a current limiting resistor of both L1 and L2 arc tubes. Under the condition that the power supply is stable, the current flowing through L1 and L2 becomes almost constant after the current is limited by the resistance, and the light emission intensities thereof become almost constant.

  When the present invention operates, the next stage device first drives the oil feed pump to suck back for a predetermined period (this period is a fixed value determined through adjustment during design, and its setting) In principle, ensure that this period is slightly longer than the time required to sack back all the essential oil in the pipeline 3 into the essential oil bottle), and via the DI 1 signal line to the device Send one transition signal.

  In the device according to the present invention, when the transition signal on the DI1 signal line is received, U2 drives the LEDO line to high level to drive the two luminous tubes of L1 and L2 to emit light, and both inputs of ADC1 and ADC2 The level width at the end is detected and used as a comparison standard of "striking oil". This period of time defining the comparison criteria is provided by the next stage device. Then, the next stage device drives the oil feed pump to start pumping in the positive direction. The regulator U2 of the device according to the present invention continuously detects the level width of both input ends of ADC1 and ADC2 and finds a change exceeding the promised width, so that the essential oil passes through the area of the corresponding light emitting tube-light receiving tube pair Immediately, a transition signal is output to the corresponding output port DO1 or DO2 to notify the next stage device to clock.

  After the present essential oil delivery is completed, the next stage device restores the signal on the DI1 signal line. The device according to the present application resets the LEDO line to a low level and turns off the two light emitting tubes L1 and L2 so as to delay their deterioration and keep relatively constant characteristics. This is advantageous for improving detection accuracy and extending the service life of the device according to the present application.

  If the next stage device does not detect an expected level transition on DO1 or DO2 after transmitting a transition signal from the DI1 signal line and a time that is several times the normal work cycle has passed, It is assumed that the essential oil in the essential oil bottle is used up, and a prompt signal may be issued as needed.

  In a more intelligent way, the DO1 and DO2 signal lines are for driving the suckback and forward direction delivery by the oil pump respectively, and two pairs of arc tubes by U2 in the device according to the present application. Calculation of the volumetric flow rate, counting the time difference between the essential oil and the light receiver pair area. Each time a transition on the DI1 signal line is received, the apparatus according to the present application achieves control of the oil feed pump by controlling the transition of the DO1 and DO2 signal lines. When it is calculated by U2 that one unit volume (e.g., 1 drop or 1 mL, etc.) of essential oil delivery is complete, positive direction delivery is stopped, and a short suckback is performed in preparation for the next delivery of oil. That is, the weighing calculation and control operation performed by the next-stage device in the above embodiment are integrated into the device according to the present application, and the next-stage device transmits the one pulse on the DI1 signal line every time the device according to the present application Deliver 1 unit of essential oil. After transmitting the pulse from the DI1 signal line, the next-stage device may detect the signal states of DO1 and DO2 and detect the completion state of the forward direction delivery, and it may be assumed that the present essential oil delivery is completed. Then, after a time delay corresponding to the suck back time, it is possible to transmit a pulse through the DI1 signal line again to request the next unit of essential oil delivery (if necessary).

  The present invention can reduce the workload of the next stage device without increasing the hardware circuit and cost substantially, and is advantageous for shortening the development cycle of the next stage device, and the next stage device is one step for cost reduction. A smaller MCU can be used.

  Based on the disclosure and teaching of the above-mentioned specification, those skilled in the art can make modifications and variations to the above embodiment. Accordingly, the present invention is not limited to the specific embodiments disclosed and described above, but some modifications and variations of the present invention should be included within the scope of the present invention. Although some specific terms are used in the present specification, these terms are for the convenience of description and do not limit the invention.

Claims (8)

The MCU includes an MCU connected to the connector of the next stage device via a serial data pin, and the LED pin of the MCU is connected to two serially connected luminous tubes, and the MCU has a plurality of ADC pins. A detection circuit of an essential oil measuring device, wherein any one ADC pin is connected to one light receiving tube through one operational amplifier to perform signal collection to the light receiving tube. The essential oil measuring device according to claim 1, further comprising: a power supply circuit which is connected to the MCU and the connector to supply power directly to the MCU and the connector and indirectly to the electronic device connected to the MCU. Detection circuit. The power supply circuit includes a regulator U2 and a capacitor C2 connected in series, the regulator U2 is connected to the VCC pin of the MCU, and the other end of the C2 is connected to the V + pin of the connector. The detection circuit of the essential oil measuring device according to claim 2. The serial data pins of the MCU include one serial data output pin DO1 and one serial data output pin DI1, and the DO1 and DI1 pins of the MCU are correspondingly connected to the DO1 and DI1 pins of the connector, respectively. The detection circuit of the essential oil measuring device according to claim 1 characterized by the above-mentioned. The serial data pins of the MCU include two serial data output pins DO1, DO2 and one serial data output pin DI1, the DO1, DO2 and DI1 pins of the MCU correspond to the DO1, DO2 and DI1 pins of the connector respectively The detection circuit of the essential oil measuring device according to claim 1, which is connected. There are two ADC pins, and two pins are ADC1 and ADC2, respectively. The ADC1 pin is connected to the photoreceiver LD1 via the operational amplifier U3, and the ADC2 pin is connected to the photoreceiver LD2 via the operational amplifier U4. The detection circuit of the essential oil measuring device according to claim 1, which is connected. The detection circuit of the essential oil measuring device according to claim 1, wherein one current limiting resistor R1 is connected between the LED pin and the two serially connected luminous tubes. The chip model number of the MCU is HT48R005. The detection circuit of the essential oil measuring device according to claim 1.