CN105091937B - Function dual-purpose type sensor - Google Patents
Function dual-purpose type sensor Download PDFInfo
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- CN105091937B CN105091937B CN201510250277.4A CN201510250277A CN105091937B CN 105091937 B CN105091937 B CN 105091937B CN 201510250277 A CN201510250277 A CN 201510250277A CN 105091937 B CN105091937 B CN 105091937B
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Abstract
The present invention realizes the function in same circuit with both flow sensor and thermal conductivity sensor and can switch the function dual-purpose type sensor that each function is used individually.Have：Heater drive circuit, the heating element at least changed with voltage between terminals according to rate of flow of fluid, voltage between terminals and temperature sensor and the output operational amplifier for determining current potential corresponding with the heater current potential of the voltage between terminals as heating element and the difference of reference potential that fluid environment temperature accordingly changes；Export the constant voltage circuit of constant voltage；Switch, is switched over to the voltage between terminals of temperature sensor are still supplied constant voltage to operational amplifier as reference potential.When the voltage between terminals of temperature sensor are supplied to as reference potential, the flow sensor changed as measure current potential according to rate of flow of fluid is acted, when constant voltage is supplied to as reference potential, the thermal conductivity sensor changed as measure current potential according to fluid thermal conductivity is acted.
Description
Technical field
The present invention relates to it is a kind of in the same circuit with heating element can as flow velocity (flow) sensor and
The function dual-purpose type sensor of thermal conductivity sensor function.
Background technology
In the past, flow sensor was used as the sensor detected for the flow velocity to fluid, thermal conductivity sensor
It is used as the sensor for being detected to thermal conductivity.In other words, each sensor is nearly all as with only respectively
The sensor of vertical detection function and be formed separately.
For example as flow sensor, following thermal flowmeter is disclosed in patent document 1, the thermal flowmeter leads to
A pair of temperature sensors of the upstream side and downstream crossing heater drive circuit and be arranged on heating element constitute electricity
Bridge circuit, the heater drive circuit is controlled such that the heating temp of heating element is higher than with certain temperature difference all the time
The environment temperature of fluid, the thermal flowmeter exports electricity according to the corresponding electric bridge of change with the resistance value of a pair of temperature sensors
Pressure obtains the flow of fluid.
Also, as the system comprising thermal conductivity sensor, following gas physics value being disclosed in patent document 2 and is determined
System：Consist of piecewise and supply constant voltage to heating element, and be configured to utilize by with the species phase with gas
The thermal conductivity answered captures heat from heating element and causes the phenomenon of the resistance change of heating element to carry out thing to gas
Property value is correctly evaluated.
Further, as the sensor that function is detected with flow rate detection function and thermal conductivity, taken off in patent document 3
The thermoelectric pile with the physics value for being capable of detection object is shown, and also there is physical properties of fluids value to calculate in addition to flow calculating section
Micrometeor (the マ イ Network ロ フ ロ ー) sensor in portion.
Prior art literature
Patent document
Patent document 1：Japanese Unexamined Patent Publication 2003-97989 publications
Patent document 2：Japanese Unexamined Patent Publication 2010-237004 publications
Patent document 3：Japanese Unexamined Patent Publication 2001-12988 publications
The content of the invention
Problems to be solved by the invention
In order to carry out flow measurement, it is necessary to be controlled such that heating element as described in Patent Document 1
Heating temp is all the time with the projecting temperature of certain temperature difference, on the other hand, in order to carry out the measure of thermal conductivity, it is necessary to such as patent
Constant voltage is supplied to heating element as document 2 is described, therefore thermal flowmeter and thermal conductivity sensor are considered as
It is different measure devices.
Although also, there is microflow sensor described in patent document 3 flow measurement function and physics value to determine work(
Can, but due to detecting temperature sensor as special thermoelectric pile with thermal conductivity, so being substantially in flow sensor
On added physics value determination sensor, the connecting line increase of distribution is carried out to temperature sensor and interface (I/F), and need should
The special circuit of the thermal conductivity detection of temperature sensor.Moreover, the microflow sensor described in patent document 3 is simply by warm
The temperature sensor of conductance detection is used for the correction purposes to the gas component fluctuation of flow sensor, and overall of sensor is not
Cross as flow sensor function.
The present invention be in view of above-mentioned situation and make, its object is to have stream in same circuit there is provided one kind
The function of fast (flow) both sensor and thermal conductivity sensor, can switch over to each function and each function is used alone
Function dual-purpose type sensor.
Means for solving the problems
The inventor of the present patent application dedicates oneself to the circuit structure and thermal conductivity of hot type flow velocity (flow) sensor
The circuit Agencies of sensor into comparative studies, as a result expect that by the major part for being configured to make heater drive circuit be logical
With, and reference potential is allowed hand over, enable the invention to, as flow velocity (flow) sensor function, can be used as thermal conductivity
Rate sensor function.
(1) in order to reach above-mentioned purpose, function dual-purpose type sensor involved in the present invention has：Heater-driven electricity
Road, it at least has：Heating element, voltage between terminals and the fluid that voltage between terminals change according to the flow velocity of fluid
The temperature sensor that accordingly changes of environment temperature and export corresponding with the difference of heater current potential and reference potential
The operational amplifier of current potential is determined, the heater current potential is the voltage between terminals of the heating element；Output is constant
The constant voltage circuit of voltage；And switch, it is to regarding the voltage between terminals of the temperature sensor as the reference potential
Supply to the operational amplifier still supplies to the operational amplifier using the constant voltage as the reference potential
Row switching, when the voltage between terminals of the temperature sensor are supplied to as the reference potential, the function dual-purpose
Type sensor is acted as the measure current potential according to the flow sensor of the change in flow of the fluid, described constant
When voltage is supplied to as the reference potential, the function dual-purpose type sensor is as the measure current potential according to the fluid
Thermal conductivity change thermal conductivity sensor acted.
The present application can have following structure according to hope.
(2) have：It is connected to the first resistor element between the measure current potential and the heating element；And connection
Second resistance element between the measure current potential and the temperature sensor, the first resistor element and described second
Resistive element forms bridge circuit together with the heating element and the temperature sensor.
(3) heating element is arranged at the diaphragm portion of the dielectric film for the cavity that covering is located on substrate, described
Temperature sensor is separately positioned on the substrate with the heating element.
(4) constant voltage circuit has the second operational amplifier and the 3rd resistor element being connected in series and the 4th electricity
Resistance element, the constant voltage quilt is used as by the medium voltage after the 3rd resistor element and the 4th resistive element partial pressure
Output.
(5) constant voltage circuit is multi-segment voltage drive circuit, and it has multiple resistive elements and multiple switch, passes through institute
The ON or OFF of multiple switch are stated, the different voltages of multistage can be exported as the medium voltage.
(6) the multi-segment voltage drive circuit has the second operational amplifier, n switch and n+1 be connected in series
Resistive element, the input terminal of the n switch and second operational amplifier is connected in parallel, second operational amplifier
The input terminal by respective switch, be applied in defined voltage source n+1 resistive element it is adjacent
Electrically connected between each pair of resistive element, by the ON or OFF of described n switch, the different voltages for allowing hand over multistage are made
For the medium voltage.
(7) also there is flow rate detection circuit, the flow rate detection circuit, which at least has, to be used for the flow direction of fluid
A pair of temperature sensors that the fluid temperature (F.T.) in trip side and downstream is detected.
(8) the flow rate detection circuit has：Second bridge circuit, it is by the upstream side for the flow direction to fluid
The fluid temperature (F.T.) upstream side temperature sensor detected, the downstream temperature that is detected for the fluid temperature (F.T.) to downstream
Degree sensor and a pair of resistive elements being connected in series are formed；And the 3rd operational amplifier, it is based on the upstream side temperature
The detection signal of sensor and the downstream temperature sensor, output accordingly changes with the flow velocity of fluid and flow direction
Measure current potential.
(9) heating element is clipped to be respectively arranged with described in the upstream side and downstream of the flow direction of fluid
Swim side temperature sensor and the downstream temperature sensor, the upstream side temperature sensor and the downstream TEMP
Device is connected in series.
The effect of invention
According to function dual-purpose type sensor involved in the present invention, reference electricity is used as in the voltage between terminals of temperature sensor
When position is supplied to, heater drive circuit is added relative to the environment temperature that temperature sensor is detected with certain temperature difference driving
Hot device element, thus as flow sensor function of the current potential according to the change in flow of fluid is determined, makees in constant voltage
When being supplied to for reference potential, correspondingly changed as the thermal conductivity of electric current and fluid between the terminal of heating element, determine electricity
Position change thermal conductivity sensor and acted, according to the invention it is thus possible to realize with the same of heating element
There is the function of both flow sensor and thermal conductivity sensor in circuit, each function can be switched over and be used alone each
The function dual-purpose type sensor of function.
Brief description of the drawings
Fig. 1 is the stereogram of the function dual-purpose type sensor involved by the first embodiment of the present invention.
Fig. 2 is the II-II directions from Fig. 1 of the function dual-purpose type sensor involved by the first embodiment of the present invention
It was observed that sectional view.
Fig. 3 is the circuit diagram of the function dual-purpose type sensor involved by the first embodiment of the present invention.
Fig. 4 is the circuit diagram of the function dual-purpose type sensor involved by the second embodiment of the present invention.
Fig. 5 is the stereogram of the function dual-purpose type sensor involved by the 3rd embodiment of the present invention.
Fig. 6 is the circuit diagram of the function dual-purpose type sensor involved by the 3rd embodiment of the present invention.
Embodiment
Hereinafter, the embodiment to the present invention is illustrated.In the record of following accompanying drawing, for same or similar
Part, is represented with same or similar symbol.But, accompanying drawing is schematical figure.Therefore, specific size etc. should reference
Illustrate to be judged below.Also, accompanying drawing also contains the different part of mutual size relationship, ratio each other certainly.
(first embodiment)
First, referring to figs. 1 to Fig. 3, the function dual-purpose type sensor 100 involved by the first embodiment of the present invention is entered
Row explanation.Fig. 1 is the stereogram of the function dual-purpose type sensor involved by the first embodiment of the present invention.Fig. 2 is the present invention
First embodiment involved by function dual-purpose type sensor the sectional view observed from Fig. 1 II-II directions.Fig. 3 is
The circuit diagram of function dual-purpose type sensor involved by the first embodiment of the present invention.
Function dual-purpose type sensor 100 involved by first embodiment is using the component structure shown in Fig. 1 and Fig. 2
Microchip, constitutes circuit to realize heater drive circuit 1 and constant voltage circuit 2 as shown in Figure 3.
As shown in Figure 1 and Figure 2, function dual-purpose type sensor 100 has：It is provided with the substrate B of cavity C and configures in base
To cover the dielectric film M of cavity C on plate B.Substrate B thickness is, for example, 0.5mm, but is not limited to the thickness of illustration.Also, substrate
B length and width size is respectively for example 1.5mm or so, but is not limited to the size of illustration.The part of dielectric film M covering cavity C
For the diaphragm of thermal insulation.
Further, function dual-purpose type sensor 100 has the heater member being arranged on the part of dielectric film M diaphragm
The part RH and temperature sensor RR for the environment temperature measurement being arranged on substrate B.Temperature sensor RR is also by resistive element
Deng composition.
Heating element RH is arranged on the center of the dielectric film M of covering cavity C diaphragm portion.Heating element RH is applied
Power-up power and generate heat, pair heated with the fluid such as the heating element RH atmosphere gas contacted.First resistor element R1 and
Second resistance element R2 is arranged on other circuit substrates (not shown), is arranged on from temperature sensor RR, heating element
The places of RH farther out.Temperature sensor RR regard the gas temperature with the thermally equilibrated atmosphere gas of substrate B as balanced gas temperature
Detected.Temperature sensor RR is separated across dielectric film M with heating element RH, is arranged on the substrate with thermal conductivity
On B.Therefore, temperature sensor RR is influenceed small by the heating from heating element RH.
As substrate B material, silicon (Si) can be used, but is also not limited to the material of illustration.It is used as dielectric film M material
Material, can be used silica (SiO2) etc., but also it is not limited to the material of illustration.Cavity C is formed by anisotropic etching etc., but
Also the processing method for being not limited to illustrate.Also, platinum can be used in heating element RH and the respective materials of temperature sensor RR
(Pt) etc., it can be formed by photoetching process etc., but be also not limited to the material and preparation method of illustration.
Function dual-purpose type sensor 100 is by being arranged on the thermal insulation member (base of the bottom surface of the function dual-purpose type sensor 100
Platform) I is fixed on container filled with atmosphere gas etc..By the way that function dual-purpose type sensor 100 is consolidated via thermal insulation member I
Due to container etc., the temperature of function dual-purpose type sensor 100 is not easily susceptible to the influence of the temperature change of the inwall of container etc..It is adiabatic
Component I thermal conductivity be preferably such as 10W/ (mK) below, but be not limited to illustrate thermal conductivity.
As shown in figure 3, with heater drive circuit 1, constant voltage circuit 2 and switch SW1.Heater drive circuit 1 to
Have less：Heating element RH that voltage between terminals change according to the flow velocity of fluid, voltage between terminals correspond to the week of fluid
The temperature sensor RR for enclosing temperature and changing and the first operational amplifier (hereinafter referred to as " operational amplifier ") U1, computing is put
Big device U1 outputs are corresponding to the heater current potential Vh and reference potential Vr of the voltage between terminals as heating element RH difference
Measure current potential.Especially, in this first embodiment, heater drive circuit 1 is transported including bridge circuit 10 and first
Amplifier U1 is calculated, the bridge circuit 10 is by heating element RH, the temperature sensor RR of environment temperature measurement, first resistor member
Part R1 and second resistance element R2 are formed.On each element of these heater drive circuits 1, heating element RH is set
On dielectric film M, other elements are arranged on circuit substrate (not shown).First operational amplifier U1+input terminal is
Reference potential terminal.Reference potential terminal is arranged between the second resistance element R2 being connected in series and temperature sensor RR,
So in the case where being not connected with the lead-out terminal of constant voltage circuit 2 described later, temperature sensor RR voltage between terminals are used as ginseng
Current potential Vr is examined to be supplied to.Further, the first operational amplifier U1+input terminal (positive input terminal) passes through TEMP
Device RR and be grounded, electrically connected by second resistance element R2 and OUT terminal.First operational amplifier U1-input terminal is (negative
Pole input terminal) the heater current potential Vh between the first resistor element R1 and heating element RH being connected in series electrically connects.
Voltage between terminals of the heater current potential Vh equivalent to heating element RH.Further, the first operational amplifier U1-input
Son is grounded by heating element RH, is electrically connected by first resistor element R1 with OUT terminal.First operational amplifier U1
OUT terminal of lead-out terminal and the function dual-purpose type sensor 100 electrically connect.
Constant voltage circuit 2 is configured to export constant voltage.Especially in this first embodiment, constant voltage circuit 2 has
There are 3rd resistor element R3, the 4th resistive element R4 and the second operational amplifier U2 being connected in series.Second operational amplifier
U2 lead-out terminal is electrically connected with switch SW1.Second operational amplifier U2+input terminal and be connected in series 3rd resistor member
Current potential V34 electrical connections between part R3 and the 4th resistive element R4.The 3rd resistor element R3 and the 4th resistance being connected in series
Element R4 one end is applied in defined power source voltage Vcc, and the other end is grounded.Second operational amplifier U2-input terminal
Electrically connected with operational amplifier U2 lead-out terminal.Circuit structure based on more than, the second operational amplifier U2 is used as buffering
Circuit and work, by 3rd resistor element R3 and the 4th resistive element R4 to power source voltage Vcc carry out partial pressure after voltage V34
It is supplied to as constant voltage.
Switch SW1 be arranged on constant voltage circuit 2 lead-out terminal and heater drive circuit 1 reference potential terminal it
Between.In the case where switch SW1 is switched on (ON), the constant voltage V34 of constant voltage circuit 2 is applied to as reference voltage Vr to be added
Hot device drive circuit 1+input terminal, in the case where switch SW1 is disconnected (OFF), the lead-out terminal of constant voltage circuit 2 is broken
Electricity, temperature sensor RR voltage between terminals as reference voltage Vr be applied to heater drive circuit 1+input terminal.
It is connected it can be desirable to switch SW1 with the control device (not shown) such as CPU (CPU).
Moreover, control device is in the case where making the function dual-purpose type sensor 100 as flow sensor function,
Switch SW1 is set to OFF state.By the operation, heating element RH using relative to environment temperature as certain ratio temperature (example
Such as, it is about 60 DEG C in the case where environment temperature is room temperature) heating.As a result, heating element RH resistance value is according to surrounding
Fluid flow velocity and change, as a result voltage corresponding with the flow velocity of fluid as determine current potential be output to heater-driven electricity
OUT terminal of the output on road 1, i.e. function dual-purpose type sensor 100.The flow velocity of fluid being capable of the parameter such as the sectional area based on pipe arrangement
It is scaled the flow of fluid.That is, function dual-purpose type sensor 100 can be made as flow sensor function.
Also, control device is in the case where making the function dual-purpose type sensor 100 as thermal conductivity sensor function,
Switch SW1 is set to ON states.By the operation, heating element RH is driven by constant voltage, and its resistance value is according to surrounding
The thermal conductivity of fluid and change, as a result the voltage corresponding with the thermal conductivity of the fluid of surrounding as determine current potential be output to plus
OUT terminal of the output of hot device drive circuit 1, i.e. function dual-purpose type sensor 100.That is, function dual-purpose type sensor can be made
100 are used as thermal conductivity sensor function.Hereinafter, further specifically illustrate.
Function dual-purpose type sensor 100 involved by first embodiment is in the case where switch SW1 is OFF, the function
Dual-purpose type sensor 100 is used as flow sensor function.In the case where switch SW1 is OFF, heater drive circuit 1
With being disconnected by the second operational amplifier U2,3rd resistor element R3 and the 4th resistive element the R4 constant voltage circuit 2 constituted.First
Operational amplifier U1 using temperature sensor RR voltage between terminals as reference voltage Vr, and by its with heating element RH plus
Thermal voltage Vh difference is exported as operation result.Protected accordingly, with respect to the temperature sensor RR of environment temperature measurement
Hold certain certain temperature and poorly control heating element RH (driving of steady temperature difference), the first operational amplifier U1 output voltage
Value corresponding with the flow velocity of fluid is shown, function dual-purpose type sensor 100 works as flow sensor.
For example, if flow of fluid, then heating element RH radiating state is improved due to forced convertion, heater member
Part RH temperature reduction, i.e. voltage is reduced.But, due to keeping certain temperature poorly to control heating element RH, so the
One operational amplifier U1 output voltage rises, and the signal voltage being directly proportional to flow velocity is output to OUT terminal.
On the other hand, in the case where switch SW1 is ON, the function dual-purpose type sensor 100 is used as thermal conductivity sensor
Function.The function dual-purpose type sensor 100 is in the case where switch SW1 is ON, the 3rd resistor element R3 being connected in series
It is applied to the 4th resistive element R4 partial pressure V34 via the second operational amplifier U2 as the reference potential Vr of constant voltage
First operational amplifier+input terminal.For example, 3rd resistor element R3 and the 4th resistive element R4 partial pressure are set into 1V's
Words, then 1V be applied to the first operational amplifier U1 for being electrically connected between temperature sensor RR and second resistance element R2+
Input terminal.Moreover, the first operational amplifier U1 electrically connected between first resistor element R1 and heating element RH into
For a pair-input terminal also due to constant pressure driving be changed into 1V.
That is, in the case where switch SW1 is ON, with by power source voltage Vcc, 3rd resistor element R3 and the 4th resistance member
Magnitude of voltage set by part R4 applies constant voltage to heating element RH, and the function dual-purpose type sensor 100 is used as thermal conductivity
Rate sensor and work.Fluid has different thermal conductivities according to its gaseous species difference, so taking by force from heating element RH
The heat taken is different according to gaseous species difference.That is, the electric current determined according to gaseous species flows in heating element RH,
Voltage corresponding with gaseous species is output to OUT terminal.
More than, the function dual-purpose type sensor 100 according to involved by first embodiment, by with heating element
ON/OFF control is carried out to switch SW1 in RH same circuit, can be to the reference potential Vr relative to the first operational amplifier
Switch over, be set to the constant voltage set by constant voltage circuit 2, or be set to detect the temperature of the environment temperature of fluid
Spend sensor RR voltage between terminals.Therefore, can in the function dual-purpose type sensor 100 involved by first embodiment
The function of dual-purpose flow velocity (flow) sensor and thermal conductivity sensor, and need not increase new for thermal conductivity sensor
Sensor or subsidiary interface (I/F) line, special circuit.
However, in the case that switch SW1 is OFF, the first operational amplifier U1 heater drive circuit 1 also can
It is enough to be used as thermal conductivity sensor function.But, the heater drive circuit 1 can be due to the thermal time constant and electricity of sensor
The frequency characteristic on road and send that the vibration of raw signal is overlapping, so becoming signals of the S/N than difference sometimes.Therefore, switch SW1 is set
S/N can be obtained than high signal by being driven for ON and with constant voltage.Function according to involved by first embodiment is simultaneous
With type sensor 100, only pass through heating element RH, the temperature sensor RR and GND of environment temperature measurement this three lines
Flow velocity (flow) or thermal conductivity can just be detected, so less can such excellent results with distribution quantity.
(the second embodiment)
Next, reference picture 4, is carried out to the function dual-purpose type sensor 200 involved by the second embodiment of the present invention
Explanation.Fig. 4 is the circuit diagram of the function dual-purpose type sensor involved by the second embodiment of the present invention.In addition, for
One embodiment identical inscape, marks identical symbol and omits the description.
As shown in figure 4, in function dual-purpose type sensor 200 involved by the second embodiment, passing through first switch SW1 electricity
The structure of the constant voltage circuit 202 of connection is different from first embodiment.The constant voltage circuit 202 can pass through multiple switch
ON/OFF switches the multi-segment voltage drive circuit of multi-segment voltage.
That is, there is the constant voltage circuit 202 of the function dual-purpose type sensor 200 involved by the second embodiment the second computing to put
Big device U2, second switch SW2, the 3rd switch SW3 and the 3rd to the 5th resistive element R3, R4, R5.The 3rd be connected in series to
5th resistive element R3, R4, R5 one end are applied in defined power source voltage Vcc, other end ground connection.Second switch SW2 and
3rd switch SW3 be connected in parallel in the second operational amplifier U2+input terminal.Second operational amplifier U2+input terminal
Pass through the 3rd resistor element R3 and the 4th in second switch SW2 and the 3rd to the 5th resistive element R3, R4, R5 being connected in series
Partial pressure V34 electrical connections between resistive element R4.Also, the second operational amplifier U2+input terminal by the 3rd switch SW3 with
Between the 4th resistive element R4 and the 5th resistive element R5 in the 3rd to the 5th resistive element R3, R4, R5 being connected in series
Partial pressure V45 is electrically connected.Second operational amplifier U2-input terminal electrically connects with operational amplifier U2 lead-out terminal, structure
Into buffer circuit.
Function dual-purpose type sensor 200 involved by second embodiment substantially have with involved by first embodiment
The same action effect of function dual-purpose type sensor 100.That is, in the function dual-purpose type sensor involved by the second embodiment
In 200, by carrying out OFF controls to first switch SW1, heater drive circuit 1 is set to be worked as flow sensor.The opposing party
Face, in the function dual-purpose type sensor 200 involved by the second embodiment, by carrying out ON controls to first switch SW1, makes
Heater drive circuit 1 works as thermal conductivity sensor.
Especially, in the function dual-purpose type sensor 200 involved by the second embodiment, two sections of switching heating can be divided to
Device element RH temperature setting.That is, by carrying out ON controls to second switch SW2, OFF controls, energy are carried out to the 3rd switch SW3
It is enough to apply high constant voltage to heating element RH.Also, by carrying out OFF controls to second switch SW2, being switched to the 3rd
SW3 carries out ON controls, can apply low constant voltage to heating element RH.
As constant voltage, two sections as described above are not limited to, msy be also constructed to that the constant of multistage can be provided
Voltage.That is, by n switch in parallel be connected to the second operational amplifier U2+input terminal, and by it is each switch be connected to n+1
Between the adjacent pair resistive element of individual resistive element, heating element RH temperature can be carried out three sections of switchings, four sections
Switching, five sections of switchings., can be to the gaseous mixtures of multiple species by carrying out multistage switching to heating element RH heating temp
Body is that the caloric value of natural gas is correctly measured.Natural gas is methane, ethane, the gaseous mixture of four kinds of gas of butane and propane
Body, different according to gaseous species, the change of thermal conductivity is also different.If heating element RH temperature is one section, then temperature of generating heat
Degree is measured with 50~60 DEG C of fixations to being adapted to the thermal conductivity of gas of the temperature.Heating element RH temperature is multistage
If, then heating temp is changed into multistage, so as to measure thermal conductivity in wider scope, can determine that gaseous species.Therefore,
Function dual-purpose type sensor 200 according to involved by the second embodiment, with for example multiple partial pressures being set to fix 1V
Constant voltage switch to advantageous effects as 1V and 2V.
(the 3rd embodiment)
Next, reference picture 5 and Fig. 6, to the function dual-purpose type sensor involved by the 3rd embodiment of the present invention
300 illustrate.Fig. 5 is the circuit diagram of the function dual-purpose type sensor involved by the 3rd embodiment of the present invention.In addition, right
In with the second embodiment identical inscape, mark identical symbol simultaneously omit the description.
As shown in figs.5 and 6, the function dual-purpose type sensor 300 involved by the 3rd embodiment is examined with flow velocity
On this point of slowdown monitoring circuit 301, is different from the second embodiment.That is, the function dual-purpose type sensor involved by the 3rd embodiment
300 use the microchip of the component structure shown in Fig. 5, heater drive circuit 1, flow rate detection circuit 301 shown in pie graph 6
And constant voltage circuit 202 and be implemented.As shown in figure 5, function dual-purpose type sensor 300 involved by the 3rd embodiment except
Outside component structure with Fig. 1, upstream is also configured with the form for clipping heating element RH in dielectric film M diaphragm portion
Side temperature sensor RU and downstream temperature sensor RD.Upstream side temperature sensor RU and downstream temperature sensor RD
It is made up of resistive element etc..
As shown in fig. 6, flow rate detection circuit 301 includes (the measurement amplification of the operational amplifier of bridge circuit 310 and the 3rd
Device) U3, the bridge circuit 310 by upstream side temperature sensor RU, downstream temperature sensor RD, the 6th and the 7th resistance member
Part R6, R7 are formed.3rd operational amplifier U3+input terminal and the 6th resistive element R6 that is connected in series and the 7th resistance member
Partial pressure V67 electrical connections between part R7.6th resistive element R6 is applied in defined supply voltage Vb, the 7th resistive element R7 quilts
Ground connection.3rd operational amplifier U3-input terminal and the upstream side temperature sensor RU that is connected in series and downstream temperature pass
Partial pressure Vud electrical connections between sensor RD.Upstream side temperature sensor RU is applied in defined supply voltage Vb, downstream temperature
Sensor RD is grounded.The OUT2 terminals electricity of 3rd operational amplifier U3 lead-out terminal and the function dual-purpose type sensor 300
Connection.OUT2 terminals control device (not shown) such as with CPU (CPU) is connected.
Function dual-purpose type 300 involved by 3rd embodiment has Fig. 1 component structure, and with the second embodiment
The heater drive circuit 1 and constant voltage circuit 202 of involved function dual-purpose type sensor 200.Therefore, the 3rd embodiment
Involved function dual-purpose type sensor 300 substantially has and the function dual-purpose type sensor involved by the second embodiment
200 same action effects.That is, in the function dual-purpose type sensor 300 involved by the 3rd embodiment, can be divided to two sections it is right
Heating element RH temperature is set for switching.By carrying out ON controls to second switch SW2, the 3rd switch SW3 is carried out
OFF is controlled, and can apply high constant voltage V34 to heater drive circuit 1.Also, by carrying out OFF to second switch SW2
Control, carries out ON controls to the 3rd switch SW3, can apply low constant voltage V45 to heater drive circuit 1.
Especially, in the function dual-purpose type sensor 300 involved by the 3rd embodiment, except the element with Fig. 1
Outside structure, also with flow circuit 301, the flow circuit 301 is configured with the form for clipping heating element RH as shown in Figure 5
Upstream side temperature sensor RU and downstream temperature sensor RD.Therefore, in the function dual-purpose involved by the 3rd embodiment
It is right as flow direction F from positive direction is transformed to opposite direction when carrying out OFF controls to first switch SW1 in type sensor 300
The voltage answered is exported from the OUT2 terminals of flow circuit 301.Therefore, sensed in the function dual-purpose type involved by the 3rd embodiment
In device 300, fluid flow direction F from changing inversely be positive direction in the case of, the output from OUT2 terminals is shown
The magnitude of voltage uniquely determined.That is, flow velocity can not only be directly read according to magnitude of voltage, stream can also be directly read according to magnitude of voltage
Dynamic direction F is positive direction or opposite direction (reference picture 5).In addition, now, although OUT terminal from heater drive circuit 1 is defeated
Go out magnitude of voltage corresponding with flow velocity, but it is that positive direction or opposite direction are all same to the flow direction F of fluid to be due to
The flow velocity output identical magnitude of voltage of absolute value, therefore the flow direction of fluid is not can determine that.
Also, when carrying out ON controls to first switch SW1, utilizing the constant electricity of the switch SW3 selections of second switch SW2 and the 3rd
Pressure is supplied to the first operational amplifier U1 as reference potential Vr, represents the thermal conductivity signal of thermal conductivity of fluid from OUT terminal
Son output.That is, the function dual-purpose type sensor 300 according to involved by the 3rd embodiment, can detect the stream of fluid
The function of dual-purpose thermal conductivity sensor on the flow sensor in dynamic direction.
(other embodiments)
The present invention is recorded by embodiment as described above, but constitute the announcement a part explanation with
And accompanying drawing should not be construed the content for limiting the invention.Based on the announcement, various replacement embodiments, embodiment and utilization
Technology all should be obvious for those skilled in the art.
For example, it is also possible to be configured to, in addition to the function dual-purpose type sensor 100 of first embodiment, also add
The flow rate detection circuit 301 of 3rd embodiment.So, present invention is to be construed as contain the various implementations do not recorded herein
Form etc..
Symbol description
1 detection circuit
2nd, 202 heater drive circuit
10 bridge circuits
100th, 200,300 function dual-purpose type sensor
301 thermal conductivities detect circuit
B substrates
C cavitys
F flow directions
M dielectric films
RH heating elements
The temperature sensor of RR environment temperature measurements
R1~R7 resistive elements
RU upstream sides temperature sensor
RD downstreams temperature sensor
SW1, SW2, SW3 are switched
U1, U2, U3 operational amplifier.
Claims (22)
1. a kind of function dual-purpose type sensor, it is characterised in that have：
Heater drive circuit, it at least has：Heating element that voltage between terminals change according to the flow velocity of fluid, terminal
Between the temperature sensor that accordingly changes with the environment temperature of the fluid of voltage and output and heater current potential and reference
The difference of current potential determines the operational amplifier of current potential accordingly, and the heater current potential is the terminal of the heating element
Between voltage；
Export the constant voltage circuit of constant voltage；And
Switch, it puts to the voltage between terminals of the temperature sensor are supplied to the computing as the reference potential
Big device, which still supplies the constant voltage to the operational amplifier as the reference potential, to be switched over,
When the voltage between terminals of the temperature sensor are supplied to as the reference potential, the function dual-purpose type is passed
Sensor is acted as the measure current potential according to the flow sensor of the change in flow of the fluid, in the constant voltage
When being supplied to as the reference potential, the function dual-purpose type sensor is used as heat of the measure current potential according to the fluid
The thermal conductivity sensor of conductance change is acted.
2. function dual-purpose type sensor as claimed in claim 1, it is characterised in that have：
It is connected to the first resistor element between the measure current potential and the heating element；And
The second resistance element between the measure current potential and the temperature sensor is connected to,
The first resistor element and the second resistance element are together with the heating element and the temperature sensor
Form bridge circuit.
3. function dual-purpose type sensor as claimed in claim 2, it is characterised in that
The heating element is arranged at the diaphragm portion of the dielectric film for the cavity that covering is located on substrate,
The temperature sensor is separately positioned on the substrate with the heating element.
4. the function dual-purpose type sensor as described in any one of claims 1 to 3, it is characterised in that
The constant voltage circuit has the second operational amplifier and the 3rd resistor element and the 4th resistive element that are connected in series,
It is defeated as the constant voltage by the medium voltage after the 3rd resistor element and the 4th resistive element partial pressure
Go out.
5. the function dual-purpose type sensor as described in any one of claims 1 to 3, it is characterised in that
The constant voltage circuit is multi-segment voltage drive circuit, and it has multiple resistive elements and multiple switch, by the multiple
The ON or OFF of switch, can be using the different voltages of multistage as after 3rd resistor element and the 4th resistive element partial pressure
Medium voltage output.
6. function dual-purpose type sensor as claimed in claim 5, it is characterised in that
The multi-segment voltage drive circuit has the second operational amplifier, n switch and the n+1 resistance member being connected in series
Part,
The input terminal of the n switch and second operational amplifier is connected in parallel,
The input terminal of second operational amplifier is by respective switch, with being applied in defined voltage source
Electrically connected between each pair of adjacent resistive element of n+1 resistive element,
By the ON or OFF of described n switch, the different voltages of multistage are allowed hand over as the medium voltage.
7. the function dual-purpose type sensor as described in any one of claims 1 to 3, it is characterised in that
Also there is flow rate detection circuit, the flow rate detection circuit, which at least has, to be used for the upstream side of the flow direction of fluid with
A pair of temperature sensors that the fluid temperature (F.T.) of trip side is detected.
8. function dual-purpose type sensor as claimed in claim 7, it is characterised in that
The flow rate detection circuit has：
Second bridge circuit, its upstream side temperature detected by the fluid temperature (F.T.) of the upstream side for the flow direction to fluid
Spend sensor, for the downstream temperature sensor detected of the fluid temperature (F.T.) to downstream and a pair of electricity being connected in series
Resistance element is formed；And
3rd operational amplifier, its detection letter based on the upstream side temperature sensor and the downstream temperature sensor
Number, export the measure current potential accordingly changed with the flow velocity of fluid and flow direction.
9. function dual-purpose type sensor as claimed in claim 7, it is characterised in that
Clip the heating element and be respectively arranged with the upstream side temperature in the upstream side and downstream of the flow direction of fluid
Spend sensor and the downstream temperature sensor, the upstream side temperature sensor and downstream temperature sensor series connection
Connection.
10. function dual-purpose type sensor as claimed in claim 8, it is characterised in that
Clip the heating element and be respectively arranged with the upstream side temperature in the upstream side and downstream of the flow direction of fluid
Spend sensor and the downstream temperature sensor, the upstream side temperature sensor and downstream temperature sensor series connection
Connection.
11. function dual-purpose type sensor as claimed in claim 4, it is characterised in that
Also there is flow rate detection circuit, the flow rate detection circuit, which at least has, to be used for the upstream side of the flow direction of fluid with
A pair of temperature sensors that the fluid temperature (F.T.) of trip side is detected.
12. function dual-purpose type sensor as claimed in claim 11, it is characterised in that
The flow rate detection circuit has：
Second bridge circuit, its upstream side temperature detected by the fluid temperature (F.T.) of the upstream side for the flow direction to fluid
Spend sensor, for the downstream temperature sensor detected of the fluid temperature (F.T.) to downstream and a pair of electricity being connected in series
Resistance element is formed；And
3rd operational amplifier, its detection letter based on the upstream side temperature sensor and the downstream temperature sensor
Number, export the measure current potential accordingly changed with the flow velocity of fluid and flow direction.
13. function dual-purpose type sensor as claimed in claim 11, it is characterised in that
Clip the heating element and be respectively arranged with the upstream side temperature in the upstream side and downstream of the flow direction of fluid
Spend sensor and the downstream temperature sensor, the upstream side temperature sensor and downstream temperature sensor series connection
Connection.
14. function dual-purpose type sensor as claimed in claim 12, it is characterised in that
Clip the heating element and be respectively arranged with the upstream side temperature in the upstream side and downstream of the flow direction of fluid
Spend sensor and the downstream temperature sensor, the upstream side temperature sensor and downstream temperature sensor series connection
Connection.
15. function dual-purpose type sensor as claimed in claim 5, it is characterised in that
Also there is flow rate detection circuit, the flow rate detection circuit, which at least has, to be used for the upstream side of the flow direction of fluid with
A pair of temperature sensors that the fluid temperature (F.T.) of trip side is detected.
16. function dual-purpose type sensor as claimed in claim 15, it is characterised in that
The flow rate detection circuit has：
Second bridge circuit, its upstream side temperature detected by the fluid temperature (F.T.) of the upstream side for the flow direction to fluid
Spend sensor, for the downstream temperature sensor detected of the fluid temperature (F.T.) to downstream and a pair of electricity being connected in series
Resistance element is formed；And
3rd operational amplifier, its detection letter based on the upstream side temperature sensor and the downstream temperature sensor
Number, export the measure current potential accordingly changed with the flow velocity of fluid and flow direction.
17. function dual-purpose type sensor as claimed in claim 15, it is characterised in that
Clip the heating element and be respectively arranged with the upstream side temperature in the upstream side and downstream of the flow direction of fluid
Spend sensor and the downstream temperature sensor, the upstream side temperature sensor and downstream temperature sensor series connection
Connection.
18. function dual-purpose type sensor as claimed in claim 16, it is characterised in that
Clip the heating element and be respectively arranged with the upstream side temperature in the upstream side and downstream of the flow direction of fluid
Spend sensor and the downstream temperature sensor, the upstream side temperature sensor and downstream temperature sensor series connection
Connection.
19. function dual-purpose type sensor as claimed in claim 6, it is characterised in that
Also there is flow rate detection circuit, the flow rate detection circuit, which at least has, to be used for the upstream side of the flow direction of fluid with
A pair of temperature sensors that the fluid temperature (F.T.) of trip side is detected.
20. function dual-purpose type sensor as claimed in claim 19, it is characterised in that
The flow rate detection circuit has：
Second bridge circuit, its upstream side temperature detected by the fluid temperature (F.T.) of the upstream side for the flow direction to fluid
Spend sensor, for the downstream temperature sensor detected of the fluid temperature (F.T.) to downstream and a pair of electricity being connected in series
Resistance element is formed；And
3rd operational amplifier, its detection letter based on the upstream side temperature sensor and the downstream temperature sensor
Number, export the measure current potential accordingly changed with the flow velocity of fluid and flow direction.
21. function dual-purpose type sensor as claimed in claim 19, it is characterised in that
Clip the heating element and be respectively arranged with the upstream side temperature in the upstream side and downstream of the flow direction of fluid
Spend sensor and the downstream temperature sensor, the upstream side temperature sensor and downstream temperature sensor series connection
Connection.
22. function dual-purpose type sensor as claimed in claim 20, it is characterised in that
Clip the heating element and be respectively arranged with the upstream side temperature in the upstream side and downstream of the flow direction of fluid
Spend sensor and the downstream temperature sensor, the upstream side temperature sensor and downstream temperature sensor series connection
Connection.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2014-103133 | 2014-05-19 | ||
| JP2014103133A JP6297918B2 (en) | 2014-05-19 | 2014-05-19 | Function combined type sensor |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN105091937A CN105091937A (en) | 2015-11-25 |
| CN105091937B true CN105091937B (en) | 2017-09-19 |
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201510250277.4A Expired - Fee Related CN105091937B (en) | 2014-05-19 | 2015-05-15 | Function dual-purpose type sensor |
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| JP (1) | JP6297918B2 (en) |
| CN (1) | CN105091937B (en) |
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| Publication number | Priority date | Publication date | Assignee | Title |
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| FR3065281B1 (en) * | 2017-04-18 | 2019-06-14 | Centre National De La Recherche Scientifique | DEVICE FOR MEASURING SPEED OR GAS FLOW |
| US10634535B2 (en) * | 2018-03-13 | 2020-04-28 | Honeywell International Inc. | Airflow sensor with gas composition correction |
| CN109459635B (en) * | 2018-11-09 | 2021-11-30 | 杭州妙娱科技有限公司 | Virtual reality game equipment fault monitoring method and device |
| JP7235057B2 (en) * | 2018-12-17 | 2023-03-08 | Tdk株式会社 | gas sensor |
| CN113576408A (en) * | 2021-07-16 | 2021-11-02 | 重庆金山医疗技术研究院有限公司 | PH capsule, PH capsule wireless detection system and esophagus pH monitoring method |
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| US5703288A (en) * | 1995-07-19 | 1997-12-30 | Ricoh Company, Ltd. | Thermally-sensitive type flow meter having a high accuracy |
| US20030119197A1 (en) * | 2001-12-20 | 2003-06-26 | Ulrich Bonne | Fluid mixture composition sensor |
| CN1982855A (en) * | 2005-12-16 | 2007-06-20 | 三菱电机株式会社 | Thermal flow rate sensor supplying digital output |
| CN102879421A (en) * | 2012-09-27 | 2013-01-16 | 广东白云学院 | Measuring device and measuring method of heat-conductivity efficiency |
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| Publication number | Priority date | Publication date | Assignee | Title |
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| JP2780911B2 (en) * | 1993-08-20 | 1998-07-30 | リコー精器株式会社 | Flow measurement method and device |
| JP3115850B2 (en) * | 1997-08-29 | 2000-12-11 | リコーエレメックス株式会社 | Sensor circuit with resistor sensor as element |
| JP2000314645A (en) * | 1999-04-30 | 2000-11-14 | Yazaki Corp | Heater drive circuit |
| JP4641359B2 (en) * | 2001-04-09 | 2011-03-02 | 矢崎総業株式会社 | Flow sensor abnormality determination device |
| US7908096B2 (en) * | 2007-09-28 | 2011-03-15 | Siargo Ltd. | Integrated micromachined thermal mass flow sensor and methods of making the same |
| JP5192431B2 (en) * | 2009-03-31 | 2013-05-08 | アズビル株式会社 | Gas property measurement system |
| JP2013246007A (en) * | 2012-05-24 | 2013-12-09 | Ngk Spark Plug Co Ltd | Exhalation sensor and alcohol concentration measuring device using the same |
| JP5981301B2 (en) * | 2012-10-29 | 2016-08-31 | 日立オートモティブシステムズ株式会社 | Thermal gas sensor |
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2014
- 2014-05-19 JP JP2014103133A patent/JP6297918B2/en not_active Expired - Fee Related
-
2015
- 2015-05-15 CN CN201510250277.4A patent/CN105091937B/en not_active Expired - Fee Related
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5703288A (en) * | 1995-07-19 | 1997-12-30 | Ricoh Company, Ltd. | Thermally-sensitive type flow meter having a high accuracy |
| US20030119197A1 (en) * | 2001-12-20 | 2003-06-26 | Ulrich Bonne | Fluid mixture composition sensor |
| CN1982855A (en) * | 2005-12-16 | 2007-06-20 | 三菱电机株式会社 | Thermal flow rate sensor supplying digital output |
| CN102879421A (en) * | 2012-09-27 | 2013-01-16 | 广东白云学院 | Measuring device and measuring method of heat-conductivity efficiency |
Also Published As
| Publication number | Publication date |
|---|---|
| CN105091937A (en) | 2015-11-25 |
| JP6297918B2 (en) | 2018-03-20 |
| JP2015219123A (en) | 2015-12-07 |
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