CN201353144Y - Human body resistance measuring device - Google Patents
Human body resistance measuring device Download PDFInfo
- Publication number
- CN201353144Y CN201353144Y CNU2008202359216U CN200820235921U CN201353144Y CN 201353144 Y CN201353144 Y CN 201353144Y CN U2008202359216 U CNU2008202359216 U CN U2008202359216U CN 200820235921 U CN200820235921 U CN 200820235921U CN 201353144 Y CN201353144 Y CN 201353144Y
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- amplifier
- resistance
- human body
- current source
- outfan
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Abstract
The utility model relates to a human body resistance measuring device, which comprises contact electrodes, an AC constant current source, a wave detector and a signal amplifier. The AC constant current source is used for providing detection current; the wave detector is used in wave detection for detection signals; the AC constant current source comprises an operational amplifier; the anti-phase end of the operational amplifier is connected with a signal generator; a reference resistance is connected between the output end and the anti-phase end of the operational amplifier; the two ends of the reference resistance are respectively connected with a contact electrode; the wave detector comprises another operational amplifier; the in-phase end and the anti-phase of the operational amplifier of the wave detector are respectively connected with the two ends of the reference resistance; the output end of the operational amplifier is connected with the input end of the signal amplifier; and the output of the signal amplifier is connected with the input end of an MCU through an analog-digital converter. With the single chip with the built-in operational amplifiers, the analog-digital converter, the PWM module and the MCU, the utility model has high degree of integration, greatly reduces the peripheral circuit, effectively decreases the failure rate, improves the stability and reliability of the circuit, and reduces the production and maintenance costs.
Description
Technical field
This utility model relates to resistive measurement, particularly a kind of device that adopts the AC measurment mode to measure human body resistance.
Background technology
In the modern life, the AC measurment human body resistance is a human body resistance mode more accurately.Resistance measurement by human body can be extrapolated body fat content, moisture, build judgement, muscle quantities, calorie health indexs such as (calorie) in conjunction with some further features of human body.Extensively utilization in healthy series products such as fat measuring device, fat title.
The existing realization has AC measurment and DC measurement dual mode in the circuit.The DC measurement mode is because the polarity effect of human body causes measurement error greatly and progressively to be replaced by the AC measurment mode.And present AC measurment circuit is to constitute circuit such as AC signal generation, constant current, detection, measurement by magnification by discrete elements such as COMS analog switch 4052 and numerous resistance, electric capacity, diode, audions, cooperate MCU control, realize date processing, its circuit complexity, number of elements is many, the trouble point is many, produces, maintenance difficulty is big, whole cost height.
Summary of the invention
The purpose of this utility model provides that a kind of number of elements is few, circuit is simply measured the human body resistance device, to reduce the fault rate of product, reduces production cost of products and maintenance cost.
This utility model is measured the human body resistance device, comprise and be used for the contact electrode that contacts with human body skin, the AC constant-current source that detects electric current is provided, the cymoscope that detection signal is carried out detection, and signal amplifier, it is characterized in that: described AC constant-current source comprises amplifier OP1, the anti-phase termination signal generator of amplifier OP1, homophase termination reference circuit meets reference resistance R5 between outfan and the end of oppisite phase, reference resistance R5 two ends respectively connect a contact electrode; Described cymoscope comprises amplifier OP2, be connected the diode D1 between amplifier OP2 outfan and the end of oppisite phase, and being connected diode D2 and resistance R 11 series arms between amplifier OP2 outfan and the end of oppisite phase, the in-phase end of amplifier OP2 and end of oppisite phase connect the two ends of described reference resistance R5 respectively by resistance R 9, resistance R 10; Described signal amplifier comprises amplifier OP3, and the homophase termination reference voltage of amplifier OP3, end of oppisite phase connect the outfan of amplifier OP2 successively by resistance R 12, diode D2, and end of oppisite phase connects described reference voltage by parallel resistor R7 and capacitor C 4 in addition; The outfan of signal amplifier connects the input of MCU by analog-digital converter.
Preferred scheme is that amplifier OP1, amplifier OP2, amplifier OP3, analog-digital converter and MCU are integrated in the same chip, with further minimizing number of elements, reduces fault rate, reduces cost.
The preferred sine-wave generator of signal generator, this sine-wave generator comprises the PWM module, and coil L1 and capacitor C 2 parallel circuits, the first end ground connection of this parallel circuit, second end is by resistance R 1 adapter PWM module outfan, and second end connects the input of described AC constant-current source by capacitor C 1.
Further, the PWM module and the MCU of amplifier OP1, amplifier OP2, amplifier OP3, analog-digital converter, sine-wave generator all can be integrated in the same chip.
The preferred 500-600 ohm of the resistance of reference resistance R5 in the above-mentioned AC constant-current source.
This measurement human body resistance device adopts the one chip of built-in some amplifiers, analog-digital converter, PWM module and MCU.Circuit part integrated level height, peripheral circuit significantly reduces, and can effectively reduce fault rate, improves the stability and the reliability of circuit, and can reduce production, maintenance cost cost.
It is controlled by MCU, has brought into play the characteristic of MCU frequency stabilization, has improved the accuracy of measuring, and has further improved the stability of circuit.
Description of drawings
Fig. 1 is the circuit diagram of exemplary embodiments; Fig. 2 is the circuit diagram of its AC constant-current source;
Fig. 3 is the circuit diagram of its cymoscope; Fig. 4 is the circuit diagram of its signal amplifier;
Fig. 5 is the circuit diagram of its sine-wave generator.
The specific embodiment
Further specify below in conjunction with accompanying drawing.With reference to Fig. 1-5, the device of this measurement human body resistance comprises two contact electrodes that are used for contacting with human body skin, and the AC constant-current source that detects electric current is provided, the cymoscope that detection signal is carried out detection, and signal amplifier.J1 among Fig. 1 and Fig. 2 is an adapter, by adapter J1 with two contact electrode places in circuit.
AC constant-current source comprises amplifier OP1, the end of oppisite phase of amplifier OP1 was connected resistance R 3 signal generators, in-phase end connects reference circuit by resistance R 4, meet reference resistance R5 between outfan and the end of oppisite phase, reference resistance R5 two ends respectively connect a contact electrode (contact electrode is connected adapter J1, does not draw among the figure).
The reference circuit that is connected in the AC constant-current source in-phase end comprises resistance R 2 and the R8 that is serially connected with between VDD and the ground, and the common port and the capacitor C between the ground 5 that are connected resistance R 2 and R8.The resistance of reference resistance R5 can be 560 ohm.
Cymoscope comprises amplifier OP2, be connected the diode D1 between amplifier OP2 outfan and the end of oppisite phase, and being connected diode D2 and resistance R 11 series arms between amplifier OP2 outfan and the end of oppisite phase, the in-phase end of amplifier OP2 and end of oppisite phase connect the two ends (AN+ and AN-) of described reference resistance R5 respectively by resistance R 9, R10.
Signal amplifier comprises amplifier OP3, homophase termination reference voltage 1/2 VDD of amplifier OP3, and end of oppisite phase connects the outfan of amplifier OP2 successively by resistance R 12, diode D2, and end of oppisite phase meets described reference voltage 1/2 VDD by parallel resistor R7 and capacitor C 4 in addition; The outfan of signal amplifier connects the input of MCU by analog-digital converter ADC.
Signal generator is a sine-wave generator, this sine-wave generator comprises the PWM module, and coil L1 and capacitor C 2 parallel circuits, the first end ground connection of this parallel circuit, second end connects PWM module outfan by resistance R 1, and second end connects the input of AC constant-current source by capacitor C 1.
The PWM module of above-mentioned amplifier OP1, amplifier OP2, amplifier OP3, analog-digital converter ADC, sine-wave generator and MCU are integrated among the same chip U1.PWM module in the chip U1 is used for generation cycle and the adjustable pulse-width modulation waveform of dutycycle difference, and the SIN terminal of chip U1 is the outfan of PWM module in this sheet.
Comprise also among the described chip U1 that one has the FLASH memorizer of power-failure memory, an interval stores MCU and calculates the calibration parameter that human body resistance needs in this memorizer.As: during calibration product, the AD value that records during adapter J 1 external calibrating resistance (R5 is in parallel with reference resistance), and adapter J1 does not connect AD value that calibrating resistance records when (promptly only having reference resistance R5) or the like.
Also comprise the beneficial amplifier PGA of an increase able to programme among the described chip U1, this PGA can replace above-mentioned amplifier OP3, constitutes high accuracy PGA amplifying circuit with above-mentioned outward element resistance R 12, diode D2, resistance R 7 and capacitor C 4 etc.
During measurement, sine-wave generator produces the PWM sine wave signal, and under the excitation of this PWM sine wave signal, AC constant-current source output detects electric current, and the electric current that flows through reference resistance R5 keeps constant.When with contact electrode with after human body skin contacts, human body resistance is connected in parallel on the reference resistance R5, the signal at cymoscope collection reference resistance R5 this moment two ends, input MCU after signal amplifier amplification, analog-digital converter conversion, and then MCU calculates the resistance value of the body of coming in and going out in conjunction with the calibration parameter in the FLASH memorizer.
The chip integration height that this device adopts, circuit is simple, greatly reduces production cost.Owing to significantly reduced peripheral cell,, improved the stability and the reliability of circuit, and can reduce maintenance cost so can effectively reduce fault rate.This device has been brought into play the characteristic of MCU frequency stabilization by MCU control, has improved the accuracy of measuring, and has further improved the stability of circuit.
Claims (9)
1, a kind of device of measuring human body resistance comprises: be used for the contact electrode that contacts with human body skin, the AC constant-current source that detects electric current is provided, the cymoscope that detection signal is carried out detection, and signal amplifier is characterized in that:
Described AC constant-current source comprises amplifier OP1, the anti-phase termination signal generator of amplifier OP1, and homophase termination reference circuit meets reference resistance R5 between outfan and the end of oppisite phase, and reference resistance R5 two ends respectively connect a contact electrode;
Described cymoscope comprises amplifier OP2, be connected the diode D1 between amplifier OP2 outfan and the end of oppisite phase, and being connected diode D2 and resistance R 11 series arms between amplifier OP2 outfan and the end of oppisite phase, the in-phase end of amplifier OP2 and end of oppisite phase connect the two ends of described reference resistance R5 respectively by resistance R 9, resistance R 10;
Described signal amplifier comprises amplifier OP3, and the homophase termination reference voltage of amplifier OP3, end of oppisite phase connect the outfan of amplifier OP2 successively by resistance R 12, diode D2, and end of oppisite phase connects described reference voltage by parallel resistor R7 and capacitor C 4 in addition; The outfan of signal amplifier connects the input of MCU by analog-digital converter.
2, the device of measurement human body resistance as claimed in claim 1 is characterized in that: described amplifier OP1, amplifier OP2, amplifier OP3, analog-digital converter and MCU are integrated in the same chip.
3, human body resistance circuit as claimed in claim 1, it is characterized in that: described signal generator is a sine-wave generator, this sine-wave generator comprises the PWM module, and coil L1 and capacitor C 2 parallel circuits, the first end ground connection of this parallel circuit, second end is by resistance R 1 adapter PWM module outfan, and second end connects the input of described AC constant-current source by capacitor C 1.
4, the device of measurement human body resistance as claimed in claim 3 is characterized in that: the PWM module and the MCU of described amplifier OP1, amplifier OP2, amplifier OP3, analog-digital converter, sine-wave generator are integrated in the same chip.
5, the device of measurement human body resistance as claimed in claim 4 is characterized in that: comprise in the described chip that one has the FLASH memorizer of power-failure memory function, an interval stores MCU and calculates the calibration parameter that human body resistance needs in this memorizer.
6, the device of measurement human body resistance as claimed in claim 4 is characterized in that: comprise the beneficial amplifier PGA of an increase able to programme in the described chip.
7, as the device of each described measurement human body resistance of claim 1-4, it is characterized in that: the reference circuit that is connected in the AC constant-current source in-phase end comprises resistance R 2 and the R8 that is serially connected with between VDD and the ground, and the common port and the capacitor C between the ground 5 that are connected resistance R 2 and R8.
8, the device of measurement human body resistance as claimed in claim 7 is characterized in that: the reference resistance R5 resistance in the described AC constant-current source is 500-600 ohm.
9, as the device of each described measurement human body resistance of claim 1-4, it is characterized in that: the reference resistance R5 resistance in the described AC constant-current source is 500-600 ohm.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CNU2008202359216U CN201353144Y (en) | 2008-12-29 | 2008-12-29 | Human body resistance measuring device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CNU2008202359216U CN201353144Y (en) | 2008-12-29 | 2008-12-29 | Human body resistance measuring device |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN201353144Y true CN201353144Y (en) | 2009-12-02 |
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Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CNU2008202359216U Expired - Lifetime CN201353144Y (en) | 2008-12-29 | 2008-12-29 | Human body resistance measuring device |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN201353144Y (en) |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103040458A (en) * | 2012-12-28 | 2013-04-17 | 深圳市千帆电子有限公司 | Human body electrophysiological signal detection instrument |
| CN103142226A (en) * | 2013-03-28 | 2013-06-12 | 苏州市豪杰机械电子设备有限公司 | Human body resistance testing method |
| CN103344834A (en) * | 2013-06-27 | 2013-10-09 | 成都网动光电子技术股份有限公司 | Device for testing body resistance |
| CN103354052A (en) * | 2013-06-28 | 2013-10-16 | 雷建设 | Resistor series-parallel connection demonstrator |
| CN105677093A (en) * | 2016-01-04 | 2016-06-15 | 京东方科技集团股份有限公司 | Touch device and electronic device |
-
2008
- 2008-12-29 CN CNU2008202359216U patent/CN201353144Y/en not_active Expired - Lifetime
Cited By (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103040458A (en) * | 2012-12-28 | 2013-04-17 | 深圳市千帆电子有限公司 | Human body electrophysiological signal detection instrument |
| CN103142226A (en) * | 2013-03-28 | 2013-06-12 | 苏州市豪杰机械电子设备有限公司 | Human body resistance testing method |
| CN103142226B (en) * | 2013-03-28 | 2016-03-02 | 苏州市豪杰机械电子设备有限公司 | Human body resistance method of testing |
| CN103344834A (en) * | 2013-06-27 | 2013-10-09 | 成都网动光电子技术股份有限公司 | Device for testing body resistance |
| CN103354052A (en) * | 2013-06-28 | 2013-10-16 | 雷建设 | Resistor series-parallel connection demonstrator |
| CN105677093A (en) * | 2016-01-04 | 2016-06-15 | 京东方科技集团股份有限公司 | Touch device and electronic device |
| WO2017118208A1 (en) * | 2016-01-04 | 2017-07-13 | 京东方科技集团股份有限公司 | Touch device and electronic device |
| CN105677093B (en) * | 2016-01-04 | 2018-06-12 | 京东方科技集团股份有限公司 | A kind of touch device and electronic equipment |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| ASS | Succession or assignment of patent right |
Owner name: SHENZHEN CHK ELECTRONICS CO., LTD. Free format text: FORMER OWNER: SHENZHEN CHK TECHNOLOGY CO., LTD. Effective date: 20130814 |
|
| C41 | Transfer of patent application or patent right or utility model | ||
| TR01 | Transfer of patent right |
Effective date of registration: 20130814 Address after: Post office building Baoan District 13 Baomin Shenzhen city Guangdong province 518101 Road 27 layer Patentee after: Shenzhen CHK Electronics Co., Ltd. Address before: Post office building Baoan District 13 Baomin Shenzhen city Guangdong province 518101 Road 27 layer Patentee before: Shenzhen CHK Technology Co., Ltd. |
|
| C56 | Change in the name or address of the patentee |
Owner name: SHENZHEN XINHUI TECHNOLOGY CO., LTD. Free format text: FORMER NAME: SHENZHEN CHK ELECTRONICS CO., LTD. |
|
| CP01 | Change in the name or title of a patent holder |
Address after: Post office building Baoan District 13 Baomin Shenzhen city Guangdong province 518101 Road 27 layer Patentee after: Xin Huike limited company of Shenzhen Address before: Post office building Baoan District 13 Baomin Shenzhen city Guangdong province 518101 Road 27 layer Patentee before: Shenzhen CHK Electronics Co., Ltd. |
|
| CX01 | Expiry of patent term |
Granted publication date: 20091202 |
|
| CX01 | Expiry of patent term |