CN103698615A

CN103698615A - Multi-frequency-band electromagnetic signal field intensity meter of universal meter

Info

Publication number: CN103698615A
Application number: CN201310739324.2A
Authority: CN
Inventors: 王志
Original assignee: Individual
Current assignee: Individual
Priority date: 2013-12-27
Filing date: 2013-12-27
Publication date: 2014-04-02

Abstract

The invention provides a multi-frequency-band electromagnetic signal field intensity meter of a universal meter. The multi-frequency-band electromagnetic signal field intensity meter is characterized by comprising a frequency selection loop, a detecting and filtering circuit, a field-effect transistor amplifying and correcting circuit and a 500 type universal meter, wherein the frequency selection loop consists of a receiving antenna ANT, a resonance coil, a semi-variable capacitor CP and a frequency selection switch Kn, the detecting and filtering circuit consists of a germanium diode D1, a capacitor C1 and a resistor R1, the selected model of the germanium diode D1 is 2AP9, and the field-effect transistor amplifying and correcting circuit consists of a field-effect transistor VT1 and a linearity potentiometer RP. Instruments specially used for electromagnetic signal field intensity in markets have excellent performance, but the selling price is high. The multi-frequency-band electromagnetic signal field intensity meter can be used for measuring the field intensity of electromagnetic signals sent by various small-sized transmitters, and measurement results of electromagnetic signal field intensity can meet ordinary technical requirements. The multi-frequency-band electromagnetic signal field intensity meter has the characteristics that the circuit structure is simple, the measurement sensitivity is higher, the work performance is stable, the manufacturing cost is low, and the like.

Description

Multimeter multiband electromagnetic signal field intensity meter

Technical field

The invention belongs to electromagnetic signal field of measuring technique, is about a kind of multimeter multiband electromagnetic signal field intensity meter.

Background technology

A lot of for measuring method and the instrument of electromagnetic signal field intensity, although specialty, for measuring the instrument function admirable of electromagnetic signal field intensity, exists price high on market, amateur unit or personnel are difficult to the defects such as acceptance.In order to make up and to overcome these problems, be necessary to develop that a kind of circuit structure is succinct, cost of manufacture is low, stable work in work and practical electromagnetic signal field strength meter device.

Multimeter multiband electromagnetic signal field intensity meter of the present invention be take frequency, and to select loop be core, the quantitative indicating device of 500 type multimeter resistance grades (R * 100) conduct that choosing is conventional, 500 type multimeters are not needed to do any change, can be used for measuring the electromagnetic signal field intensity that various small-sized transmitters send, the measurement result of electromagnetic signal field intensity can meet general specification, it have circuit structure simple, measure that sensitivity is higher, the feature such as stable work in work, cost of manufacture are low.

Below describe multimeter multiband electromagnetic signal field intensity meter of the present invention related relevant technologies content in manufacturing process in detail.

Summary of the invention

Goal of the invention and beneficial effect: a lot of for measuring method and the instrument of electromagnetic signal field intensity, although specialty, for measuring the instrument function admirable of electromagnetic signal field intensity, exists price high on market, amateur unit or personnel are difficult to the defects such as acceptance.Multimeter multiband electromagnetic signal field intensity meter of the present invention be take frequency, and to select loop be core, the quantitative indicating device of 500 type multimeter resistance grades (R * 100) conduct that choosing is conventional, 500 type multimeters are not needed to do any change, can be used for measuring the electromagnetic signal field intensity that various small-sized transmitters send, the measurement result of electromagnetic signal field intensity can meet general specification, it have circuit structure simple, measure that sensitivity is higher, the feature such as stable work in work, cost of manufacture are low.

Circuit working principle: multimeter multiband electromagnetic signal field intensity meter is selected loop by resonance coil L, semivariable capacitor CP component frequency, and its numerical values recited is depending on measured signal frequency; By germanium diode, be responsible for the detection of high-frequency electromagnetic signal, capacitor C 1 is responsible for the filtering of rectified signal, by detection, obtains the above DC voltage of 0.7V, and field effect transistor VT1 plays rectified signal and amplifies and buffer action.Before the electromagnetic signal of sending at measurand transmitter, 500 type multimeters are placed in to R * 100 Ω shelves, the drain D utmost point of field effect transistor VT1 is connected to the black meter pen jack of 500 type multimeters, circuit ground GND is connected to the red test pencil jack of 500 type multimeters, adjusts linear potentiometer RP and can make 500 type multimeter pointers make zero (that is: the resistance of pointer indication is for infinitely great).When measuring electromagnetic signal field intensity, the resistance value of 500 type multimeter pointers indications is less, illustrates that the field intensity of electromagnetic signal of tested electromagnetic signal is larger; Otherwise the field intensity of tested electromagnetic signal is little.

Technical scheme: multimeter multiband electromagnetic signal field intensity meter, it comprises frequency selection loop, detection and filtering circuit, field effect transistor amplification and correcting circuit, 500 type multimeters, it is characterized in that:

Frequency is selected loop: it is comprised of receiving antenna ANT, resonance coil, semivariable capacitor CP, frequency selective switch Kn, the activity termination receiving antenna ANT of frequency selective switch Kn and the moving plate of semivariable capacitor CP, the Same Name of Ends connection circuit ground GND of the stator of semivariable capacitor CP and resonance coil L1, the contact 1 of frequency selective switch Kn connects the different name end of resonance coil L1, the contact 2 of frequency selective switch Kn connects the Same Name of Ends of resonance coil L2, and the contact 3 of frequency selective switch Kn connects the different name end of resonance coil L3;

Detection and filtering circuit: it is comprised of germanium diode D1, capacitor C 1 and resistance R 1, the model that germanium diode D1 selects is 2AP10, the positive pole of germanium diode D1 connects the movable end of frequency selective switch Kn, the negative pole of germanium diode D1 connects one end of capacitor C 1 and one end of resistance R 1, the other end connection circuit ground GND of the other end of capacitor C 1 and resistance R 1;

Field effect transistor is amplified and correcting circuit: it is comprised of field effect transistor VT1, linear potentiometer RP and 500 type multimeters, the grid G of field effect transistor VT1 connects the negative pole of germanium diode D1, the source S of field effect transistor VT1 connects one end of linear potentiometer RP, the other end of linear potentiometer RP and movable end connection circuit ground GND thereof, the drain D of field effect transistor VT1 connects the black meter pen jack of 500 type multimeters, the red test pencil jack connection circuit ground GND of 500 type multimeters.

Accompanying drawing explanation

Accompanying drawing 1 is the embodiment circuit working schematic diagram that the invention provides a multimeter multiband electromagnetic signal field intensity meter; Resonance coil L in accompanying drawing 1 comprises resonance coil L1, resonance coil L2 and resonance coil L3.

Embodiment

According to multimeter multiband electrometer of field strength circuit working schematic diagram and the accompanying drawing explanation shown in accompanying drawing 1, and according to annexation between components and parts in the each several part circuit described in summary of the invention, and the components and parts technical parameter described in embodiment requires and circuit production main points are implemented to realize the present invention, below in conjunction with embodiment, correlation technique of the present invention is further described.

The selection of components and parts and technical parameter thereof

VT1 is field effect transistor, and the model of selecting is 3DJ6;

D1 is germanium diode, and the model of selecting is 2AP9;

CP is semivariable capacitor, the magnetic medium semivariable capacitor of selecting, and its capacity is 5～20PF;

The resistance 1M Ω of resistance R 1;

C1 is electric capacity of the dacron, and its capacity is 0.01 μ F, the withstand voltage 40V of being;

RP is linear potentiometer, and its resistance is 1.2K Ω;

Kn is frequency selective switch, selects single-pole triple-throw (SPTT) or hilted broadsword four throw switches;

Measure gauge outfit and use 1 500 type multimeter.

Circuit production main points, circuit debugging and using method

The making of resonance coil L: use ￠ 10 insulating material as resonance coil skeleton, with 0.07mm wire-wound multiply enameled wire, resonance coil L1 is flat around 56 circles, resonance coil L2 flat around, 10 circles, resonance coil L3 is flat around 10 circles, in the winding process of resonance coil L, should note Same Name of Ends and the tap of resonance coil;

The shell of multimeter multiband electromagnetic signal field intensity meter is cut and can not be used metal material to make! Otherwise tested electromagnetic signal will conductively-closed and is affected measurement result;

Because of the circuit structure of multimeter multiband electromagnetic signal field intensity meter fairly simple, comparison is easy, as long as the electronic devices and components performance of generally selecting is intact, and the components and parts annexation in accompanying drawing 1 is welded to specifications, physical connection line and welding quality are after careful inspection is correct, and circuit of the present invention does not substantially need to carry out any debugging and can normally work;

Adjust linear potentiometer RP and make 500 type multimeter pointers make zero (that is: the resistance of pointer indication is for infinitely great).When measuring electromagnetic signal field intensity, the resistance value of 500 type multimeter pointers indications is less, illustrates that the field intensity of electromagnetic signal of tested electromagnetic signal is larger; Otherwise the field intensity of tested electromagnetic signal is little;

Frequency selective switch Kn is for the tested electromagnetic signal frequency of coarse adjustment, and semivariable capacitor CP is for the tested electromagnetic signal frequency of fine tuning, until be tuned to the field intensity numerical value reading of tested electromagnetic signal frequency maximum;

The field intensity size of grasping multimeter multiband electromagnetic signal field intensity meter and the correct tested electromagnetic signal of interpretation, needs certain use procedure to accumulate experience.

Claims

1. a multimeter multiband electromagnetic signal field intensity meter, it comprises that frequency selects loop, detection and filtering circuit, field effect transistor amplification and correcting circuit, 500 type multimeters, it is characterized in that:

Described frequency selects loop to be comprised of receiving antenna ANT, resonance coil, semivariable capacitor CP, frequency selective switch Kn, the activity termination receiving antenna ANT of frequency selective switch Kn and the moving plate of semivariable capacitor CP, the Same Name of Ends connection circuit ground GND of the stator of semivariable capacitor CP and resonance coil L1, the contact 1 of frequency selective switch Kn connects the different name end of resonance coil L1, the contact 2 of frequency selective switch Kn connects the Same Name of Ends of resonance coil L2, and the contact 3 of frequency selective switch Kn connects the different name end of resonance coil L3;

Described detection and filtering circuit are comprised of germanium diode D1, capacitor C 1 and resistance R 1, the model that germanium diode D1 selects is 2AP9, the positive pole of germanium diode D1 connects the movable end of frequency selective switch Kn, the negative pole of germanium diode D1 connects one end of capacitor C 1 and one end of resistance R 1, the other end connection circuit ground GND of the other end of capacitor C 1 and resistance R 1;

Described field effect transistor is amplified and correcting circuit is comprised of field effect transistor VT1, linear potentiometer RP and 500 type multimeters, the grid G of field effect transistor VT1 connects the negative pole of germanium diode D1, the source S of field effect transistor VT1 connects one end of linear potentiometer RP, the other end of linear potentiometer RP and movable end connection circuit ground GND thereof, the drain D of field effect transistor VT1 connects the black meter pen jack of 500 type multimeters, the red test pencil jack connection circuit ground GND of 500 type multimeters.