CN211349660U

CN211349660U - Electrician safety operation examination equipment

Info

Publication number: CN211349660U
Application number: CN201921563280.1U
Authority: CN
Inventors: 赵洪华; 高晓岚
Original assignee: Individual
Current assignee: Individual
Priority date: 2019-09-19
Filing date: 2019-09-19
Publication date: 2020-08-25
Anticipated expiration: 2029-09-19

Abstract

The utility model discloses an electrician's safety operation examination equipment, including testboard and universal meter, wherein, the testboard is less than or equal to 36V alternating current through the step-down circuit output, just be equipped with the voltmeter on the testboard, work as the voltmeter and universal meter electricity respectively is connected behind the output of step-down circuit, the true voltage that all shows the alternating current is 380V. The utility model has the advantages that on one hand, the output voltage is changed into the alternating current of not higher than 36V to be used as a power supply for electrician operation, when the examiner performs the operation examination, even if the operation error occurs, the safety accident can not be caused, and the operation safety of the examiner is greatly improved; on the other hand, the output voltage of the test board measured by the voltmeter in the test board and the universal meter externally connected with the test board is 380V alternating current, so that an examiner can think that the test is performed in a real operation environment, the authenticity of the examination operation is increased, and the actual safe operation level of the examiner can be tested to the greatest extent.

Description

Electrician safety operation examination equipment

Technical Field

The utility model relates to an electrician's operation field, concretely relates to electrician's safety operation examination equipment.

Background

In the low-voltage electrician examination link of special homework, at present, two implementation modes are provided, namely simulation and actual operation, and the two examination modes respectively have different defects.

The simulation has higher safety, can ensure the operation safety of the examiners, but can not truly restore the working scene, and for low-level basic level electricians, the real operating environment can not be realized, and the real operating level of the examiners can not be tested.

The actual operation is to perform examination operation under real conditions, so that a real operation environment can be restored, and the actual operation level of an examiner can be reflected to the maximum extent. However, the 380V high voltage is adopted in actual operation, and once the examination operation is wrong, personal injury is easily caused, and the safety is not high. As a special examination base, the safety of the examination link is always the most important. Therefore, under the condition of ensuring safety, the problem that the examiner needs to carry out the most real electrician operation examination becomes an urgent solution.

SUMMERY OF THE UTILITY MODEL

Do not possess the examination authenticity in order to solve current electrician's examination under the condition that has the security, and under the condition that possesses examination operation authenticity, there is the problem of great potential safety hazard again, the utility model aims to provide an authenticity that can enough restore electrician's examination operation environment, the examination equipment of the personnel's security of guaranteeing the examination again.

The utility model discloses the technical scheme who adopts does:

the utility model provides an electrician's safety operation examination equipment, includes testboard and universal meter, wherein, the testboard passes through the alternating current that step-down circuit output is less than or equal to 36V, just be equipped with the voltmeter on the testboard, work as the voltmeter with the universal meter electricity is connected respectively behind the output of step-down circuit, all show that the true voltage of alternating current is 380V.

Preferably, the step-down circuit comprises a first transformer, a first circuit breaker and a second circuit breaker, wherein the first circuit breaker and the second circuit breaker are respectively provided with three switch branches;

the input end of the first transformer is electrically connected with 380V three-phase alternating current, and the first transformer comprises 3 output ends which are respectively a first voltage output end, a second voltage output end and a third voltage output end;

the first voltage output end is electrically connected with a first switch branch of the first circuit breaker and then is connected with a first switch branch of the second circuit breaker in series, the second voltage output end is electrically connected with a second switch branch of the first circuit breaker and then is connected with a second switch branch of the second circuit breaker in series, and the third voltage output end is electrically connected with a third switch branch of the first circuit breaker and then is connected with a third switch branch of the second circuit breaker in series;

the output ends of a first switch branch, a second switch branch and a third switch branch of the second circuit breaker are respectively used as a first output end, a second output end and a third output end of the voltage reduction circuit, and the voltage reduction circuit is further provided with a zero line output end.

Preferably, the voltmeter is connected in parallel between the first output end and the third output end, a voltage stabilizing power supply circuit is arranged inside the voltmeter, and two wiring ends of the voltmeter are respectively and electrically connected with the output end of the voltage stabilizing power supply circuit.

Preferably, the voltage-stabilizing power supply circuit comprises a second transformer, a rectifying and filtering sub-circuit, an LM317 type voltage stabilizer, a first resistor, an adjustable resistor, a first capacitor, a second capacitor, a third capacitor, a first rectifying diode and a second rectifying diode;

one end of the second transformer is electrically connected between the first switch branch of the first circuit breaker and the first switch branch of the second circuit breaker, the other end of the second transformer is electrically connected between the third switch branch of the first circuit breaker and the third switch branch of the second circuit breaker, the output end of the second transformer is electrically connected with the input end of the rectification filter sub-circuit, and the output end of the rectification filter sub-circuit is respectively and electrically connected with one end of the first capacitor, the negative electrode of the first rectification diode and the voltage input end of the LM317 type voltage stabilizer;

the voltage regulating end of the LM317 type voltage stabilizer is respectively and electrically connected with one end of the adjustable resistor, one end of the first resistor, one end of the second capacitor and the anode of the second rectifying diode;

the voltage output end of the LM317 type voltage stabilizer is respectively and electrically connected with the anode of the first rectifying diode, the other end of the first resistor, the cathode of the second rectifying diode and one end of the third capacitor;

the other end of the first capacitor, the other end of the adjustable resistor, the resistor adjusting end, the other end of the second capacitor and the other end of the third capacitor are grounded respectively, and two wiring ends of the voltmeter are electrically connected with two ends of the third capacitor respectively.

Optimally, a measuring circuit for measuring voltage is arranged in the universal meter, wherein the measuring circuit comprises a TSC7106 analog-to-digital conversion chip, an LCD (liquid crystal display), a fourth capacitor, a fifth capacitor, a second resistor, a first switch, a third resistor, a fourth resistor, a fifth resistor, a sixth resistor, a seventh resistor and a third rectifier diode;

the positive electrode input end of the TSC7106 type analog-to-digital conversion chip is electrically connected to one end of the fourth capacitor and one end of the second resistor, the other end of the second resistor is electrically connected to one end of the first switch, the other end of the first switch is electrically connected to one end of the third resistor and one end of the fourth resistor, the other end of the third resistor is electrically connected to one end of the fifth resistor and one end of the fifth capacitor, the other end of the fifth resistor is electrically connected to the negative electrode of the third rectifying diode after being connected in series with the sixth resistor, and the positive electrode of the third rectifying diode is used as the input end of the measuring circuit;

the other end of the fourth resistor is electrically connected with one end of the seventh resistor, the other end of the fifth capacitor, the other end of the seventh resistor, the other end of the fourth capacitor and the negative input end of the TSC7106 analog-to-digital conversion chip are respectively and electrically connected with the COM end of the TSC7106 analog-to-digital conversion chip, and the output end of the TSC7106 analog-to-digital conversion chip is electrically connected with the LCD.

Preferably, the alternating current motor control circuit further comprises a first control circuit for controlling the alternating current motor to continuously operate, wherein the input end of the first control circuit is electrically connected with the output end of the voltage reduction circuit, and the output end of the first control circuit is electrically connected with the three-phase electric access end of the first alternating current motor.

The alternating current motor voltage reduction circuit is characterized by further comprising a second control circuit used for controlling the positive and negative rotation of the alternating current motor, wherein the input end of the second control circuit is electrically connected with the output end of the voltage reduction circuit, and the output end of the second control circuit is electrically connected with the three-phase electric access end of the second alternating current motor.

The optimized single-phase electric energy watchband illuminating lamp wiring circuit is further included, wherein a live wire wiring end of the single-phase electric energy watchband illuminating lamp wiring circuit is electrically connected with any one of the first output end, the second output end and the third output end, and a zero wire wiring end of the single-phase electric energy watchband illuminating lamp wiring circuit is electrically connected with the zero wire output end.

Preferably, the base is provided with a support rod, wherein one end of the support rod, which is far away from the base, is fixedly connected with the bottom surface of the rectangular mounting frame, and a triangular stable structure is formed among the support rod, the base and the rectangular mounting frame.

The optimized transformer comprises a three-phase four-wire system transformer wiring control circuit, wherein the input end of the three-phase four-wire system transformer wiring control circuit is electrically connected with the output end of the voltage reduction circuit.

The utility model has the advantages that:

(1) the utility model relates to an electrician's safety operation examination equipment, the utility model discloses a step-down circuit makes the testboard output be not higher than 36V's alternating current to make inside voltmeter of testboard and external universal meter all show the alternating current that true voltage is 380V simultaneously.

Through the design, on one hand, the output voltage is changed into the alternating current of not higher than 36V to be used as a power supply for electrician operation, so that when an examiner performs an operation examination, even if an operation mistake occurs, safety accidents cannot be caused, and the operation safety of the examiner is greatly improved; on the other hand, the actual values of the output voltage of the test bench measured by the voltmeter in the test bench and the external multimeter are 380V alternating current, so that the examiner can think that the actual values are the 380V alternating current in the real operation environment, the authenticity of the examination operation is increased, and the actual operation level of the examiner can be tested to the maximum extent.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to these drawings without creative efforts.

Fig. 1 is a specific circuit diagram of the voltage reduction circuit provided by the present invention.

Fig. 2 is a specific circuit diagram of a regulated power supply circuit provided by the present invention.

Fig. 3 is a specific circuit diagram of the measurement circuit provided by the present invention.

Fig. 4 is a specific circuit diagram of the first control circuit provided by the present invention.

Fig. 5 is a specific circuit diagram of a second control circuit provided by the present invention.

Fig. 6 is a specific circuit diagram of the lighting circuit of the single-phase electric energy watchband.

Fig. 7 is a specific circuit diagram of the wiring control circuit of the three-phase four-wire system transformer provided by the utility model.

Detailed Description

The invention will be further elucidated with reference to the embodiments described hereinafter. It should be noted that the description of the embodiments is provided to help understanding of the present invention, but the present invention is not limited thereto.

The term "and/or" herein is merely an association relationship describing an associated object, and means that there may be three relationships, e.g., a and/or B, which may mean: a exists alone, B exists alone, and A and B exist at the same time, and the term "/and" is used herein to describe another association object relationship, which means that two relationships may exist, for example, A/and B, may mean: a alone, and both a and B alone, and further, the character "/" in this document generally means that the former and latter associated objects are in an "or" relationship.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of example embodiments of the invention. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms "comprises," "comprising," "includes," and/or "including," when used herein, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, numbers, steps, operations, elements, components, and/or groups thereof.

It is to be understood that although the terms first, second, third, etc. may be used herein to describe various information, such information should not be limited to these terms. These terms are only used to distinguish one type of information from another. For example, first information may also be referred to as second information, and similarly, second information may also be referred to as first information, without departing from the scope of the present disclosure. The word "if" as used herein may be interpreted as "at … …" or "when … …" or "in response to a determination", depending on the context.

Furthermore, the particular features, structures, functions, or characteristics may be combined in any suitable manner in one or more embodiments. For example, a first embodiment may be combined with a second embodiment as long as the particular features, structures, functions, or characteristics associated with the two embodiments are not mutually exclusive.

Example one

As shown in fig. 1 to 7, the examination device for electrician safe operation provided in this embodiment includes a test board and a multimeter, wherein the test board outputs an ac power lower than or equal to 36V through a voltage reduction circuit, and the test board is provided with a voltmeter PV, and when the voltmeter PV and the multimeter are electrically connected to an output terminal of the voltage reduction circuit, the actual voltage of the ac power is 380V.

The test bench is used as an operation platform for electricians to operate examinations and directly provides working power supply for various examination equipment modules.

In this embodiment, the test bench is directly connected to a 380V three-phase alternating-current power supply, and then converts the 380V three-phase alternating-current power supply into an alternating-current power supply not higher than 36V through an internal voltage reduction circuit, so as to be used by various examination devices, in this embodiment, the voltage reduction circuit outputs a 36V alternating-current power supply.

Through the design, 380V three-phase alternating current is reduced to alternating current not higher than 36V, so that the operation safety during an electrician examination can be improved, even if an operation error occurs, the alternating current below 36V and 36V cannot cause life danger to the examinee, and the examination safety is greatly improved.

The test bench is also provided with a voltmeter PV, namely the voltmeter PV can measure the output voltage of the test bench, namely the voltage after passing through the voltage reduction circuit. In the embodiment, the reading plate of the voltmeter PV is embedded on the surface of the test board, so that the examiner can quickly know the output voltage of the test board.

The universal meter is a tool for enabling an examiner to automatically access the test board to measure the output voltage, and before an electrician operates an examination, the universal meter is usually used for measuring the output voltage of the test board so as to judge whether the output voltage reaches an examination standard and a standard voltage of examination equipment.

In the embodiment, the voltmeter PV is directly electrically connected to the output end of the voltage reduction circuit, and when the circuit is turned on, the voltmeter PV displays an alternating current with a real voltage of 380V; and after the examiner accesses the universal meter to the output end of the voltage reduction circuit by himself, the universal meter displays 380V alternating current.

In the embodiment, the multimeter and the voltmeter PV measure the actual voltage of the ac power at the output end of the step-down circuit to be 380V, i.e. the actual voltage of the ac power may be between 370V and 390V.

Through the design, the voltmeter PV on the test board and the accessed multimeter display that the real voltage at the output end of the voltage reduction circuit is 380V alternating current, so that an examiner can think that the examiner still takes an examination under the real operating environment, the authenticity of examination operation is increased, and the operating level of the examiner under the real environment is tested to the maximum extent.

Preferably, the step-down circuit comprises a first transformer TM, a first breaker QF1 and a second breaker QF2, wherein the first breaker QF1 and the second breaker QF2 are respectively provided with three switching branches.

The input end of the first transformer TM is electrically connected with 380V three-phase alternating current, and the first transformer TM includes 3 output ends, namely a first voltage output end L11, a second voltage output end L22 and a third voltage output end L33.

The first voltage output end L11 is connected in series with the first switch branch of the second circuit breaker QF2 after being electrically connected with the first switch branch of the first circuit breaker QF1, the second voltage output end L22 is connected in series with the second switch branch of the second circuit breaker QF2 after being electrically connected with the second switch branch of the first circuit breaker QF1, and the third voltage output end L33 is connected in series with the third switch branch of the second circuit breaker QF2 after being electrically connected with the third switch branch of the first circuit breaker QF 1.

The output ends of the first switch branch, the second switch branch and the third switch branch of the second circuit breaker QF2 are respectively used as a first output end U1, a second output end V2 and a third output end W3 of the voltage reduction circuit, and the voltage reduction circuit is further provided with a zero line output end N1.

As shown in fig. 1, the voltage-reducing circuit is explained in detail as follows:

the first transformer TM is a three-phase transformer, and its input terminal is electrically connected to 380V three-phase power, that is, L1, L2, and L3 in fig. 1 are input terminals of the first transformer TM, and are used for receiving 380V three-phase power, and when the 380V three-phase power is received, the voltage of the first transformer TM is reduced, and the voltage is changed into an alternating current not higher than 36V. Of course, the alternating current obtained by voltage reduction is also three-phase alternating current; in the present embodiment, the voltage is reduced to 36V ac.

The first transformer TM has three output terminals corresponding to three phases of the three-phase alternating current, namely, a first voltage output terminal L11, a second voltage output terminal L22, and a third voltage output terminal L33, and each voltage output terminal is electrically connected to a switch branch of the first circuit breaker QF1 and then is connected to a switch branch of the second circuit breaker QF2 in series. As shown in fig. 1. Through setting up first circuit breaker QF1 and second circuit breaker QF2, when serious overload, short circuit or undervoltage trouble take place for the circuit, the safe in utilization of circuit can be guaranteed to the shutdown circuit that can be automatic.

And the output end of the whole step-down circuit is provided with 4, namely a first output end U1, a second output end V2, a third output end W3 and a zero line output end N1, in this embodiment, the first output end U1, the second output end V2 and the third output end W3 are output ends of 36V three-phase power.

In this embodiment, in order to enable the examiner to grasp the working condition of the step-down circuit, that is, the working condition of the test board in real time, an indicator lamp HG is further provided, as shown in fig. 1, one end of the indicator lamp HG is electrically connected between the first switch branch of the first circuit breaker QF1 and the first switch branch of the second circuit breaker QF2, and the other end of the indicator lamp HG is electrically connected between the second switch branch of the first circuit breaker QF1 and the second switch branch of the second circuit breaker QF 2. The working state of the voltage reduction circuit can be mastered in real time through the indicator lamp HG, and once overload, short circuit or undervoltage fault occurs, when the first circuit breaker QF1 is disconnected, the indicator lamp HG can be extinguished to indicate that the circuit has fault.

In the present embodiment, in order to make the voltmeter PV and the multimeter display the measured voltage as 380V ac when the actual voltage is lower than or equal to 36V ac, the internal circuits of the voltmeter PV and the multimeter are changed as follows.

Preferably, the voltmeter PV is connected in parallel between the first output end U1 and the third output end W3, a regulated power supply circuit is arranged inside the voltmeter PV, and two terminals of the voltmeter PV are respectively electrically connected with an output end of the regulated power supply circuit.

Specifically, the voltage-stabilized power supply circuit comprises a second transformer T, a rectifying and filtering sub-circuit, an LM317 type voltage stabilizer V1, a first resistor R1, an adjustable resistor RP, a first capacitor C1, a second capacitor C2, a third capacitor C3, a first rectifying diode VD5 and a second rectifying diode VD 6.

One end T1 of the second transformer T is electrically connected between the first switch branch of the first breaker QF1 and the first switch branch of the second breaker QF2, the other end T2 of the second transformer T is electrically connected between the third switch branch of the first breaker QF1 and the third switch branch of the second breaker QF2, the output end of the second transformer T is electrically connected with the input end of the rectifying and filtering sub-circuit, and the output end of the rectifying and filtering sub-circuit is electrically connected with one end of the first capacitor C1, the cathode of the first rectifying diode VD5 and the voltage input end V11 of the LM317 type voltage stabilizer V1 respectively.

The voltage regulation end V12 of the LM317 type voltage stabilizer V1 is respectively and electrically connected with one end of the adjustable resistor RP, one end of the first resistor R1, one end of the second capacitor C2 and the anode of the second rectifying diode VD 6.

The voltage output end V13 of the LM317 type voltage stabilizer V1 is respectively and electrically connected with the anode of the first rectifying diode VD5, the other end of the first resistor R1, the cathode of the second rectifying diode VD6 and one end of the third capacitor C3.

The other end of the first capacitor C1, the other end and the resistance adjusting end of the adjustable resistor RP, the other end of the second capacitor C2 and the other end of the third capacitor C3 are respectively grounded, and two terminals of the voltmeter PV are respectively electrically connected with two ends of the third capacitor C3.

As shown in fig. 1 and 2, the internal circuit of the voltmeter PV, i.e., the regulated power supply circuit, is specifically described below:

firstly, the voltage stabilizing power supply circuit is located inside the voltmeter PV, after the voltage PV is connected in parallel between the first output end U1 and the third output end W3, the voltage reduced by the first transformer TM will firstly pass through the voltage stabilizing power supply circuit, and will be connected to two terminals of the voltmeter PV at last, that is, the voltage actually measured by the voltmeter PV is the alternating current reduced by the voltage reducing circuit, that is, the alternating current is not higher than 36V.

As shown in fig. 2, the specific connection relationship between the second transformer T and the step-down circuit is: one end T1 of the second transformer T is electrically connected between the first switching branch of the first breaker QF1 and the first switching branch of the second breaker QF2, and the other end T2 of the second transformer T is electrically connected between the second switching branch of the first breaker QF1 and the second switching branch of the second breaker QF 2.

In this embodiment, the turns ratio of the two iron cores in the second transformer T is 1:1, that is, the input ac power is not transformed, which is, for example, 36V ac power in this embodiment.

Because the input is three-phase voltage, the generated alternating voltage needs rectification and filtering, and the rectification and filtering sub-circuit can realize rectification and filtering of the alternating voltage, wherein the rectification refers to changing the alternating voltage with positive and negative changes into unidirectional pulsating voltage. The filtering function is to reduce the output voltage ripple coefficient and make the waveform smoother. The rectifying and filtering sub-circuit is used for obtaining a direct current voltage with a flat waveform.

After the direct-current voltage with the straight waveform is obtained, the voltage can be stabilized and output through the LM317 type voltage stabilizer V1, and the output voltage can be continuously adjusted through adjusting the adjustable resistor RP. In fig. 2, the first capacitor C1 has the function of eliminating parasitic oscillation, the second capacitor C2 has the function of suppressing ripples, and the third capacitor C3 has the function of improving the transient response of the LM317 type voltage regulator V1; the first rectifying diode VD5 and the second rectifying diode VD6 function as protection when the first capacitor C2 leaks current or the adjusting end of the adjustable resistor RP is short-circuited. Finally, the voltage regulated by the LM317 type voltage regulator V1 is input into the voltmeter PV, and the voltage is displayed through the voltmeter PV.

The principle of measuring the voltage by the voltmeter PV is as follows: and measuring the current in the loop, thereby realizing the measurement of the voltage.

Therefore, the voltage meter PV is modified to keep the current of its internal circuit the same as that of the voltage of 380V when measuring the voltage of 36V.

In summary, it is shown that: the transformation principle of the voltmeter PV is as follows: under the condition that the original circuit of the voltmeter PV is not changed, when the 380V alternating current voltage is measured, corresponding current is generated in a loop through the internal resistance of the voltmeter PV, the current drives the voltage to display, and the voltage displays 380V. When the resistance value of the circuit resistor in the voltmeter PV is reduced (namely, the adjustable resistor RP), when the voltage of 36V of alternating current is measured, the current passing through the voltmeter PV is kept unchanged due to the corresponding reduction of the resistance value, so that the voltage display is also driven, and the voltmeter PV is displayed as 380V by changing the measuring range of the voltmeter PV.

Of course, if the output voltage is less than 36V, the principle is the same as above, and if the current in the voltmeter PV is consistent with the measurement 380V, the measurement voltage can be 380V.

In this embodiment, as shown in fig. 2, the rectifying-filtering sub-circuit includes a rectifying bridge UR and a sixth capacitor C6, where the rectifying bridge UR includes two output terminals, one of which is grounded, and the other is connected to the sixth capacitor C6 and the voltage input terminal V11 of the LM317 type regulator V1; i.e. the rectifier bridge UR rectifies the ac voltage and the sixth capacitor C6 filters the ac voltage.

In this embodiment, the whole operation indicator LED of the regulated power supply circuit can be further provided to indicate the operation condition of the whole circuit. I.e. as shown in fig. 2.

Preferably, a measuring circuit for measuring voltage is arranged in the multimeter, wherein the measuring circuit comprises a TSC7106 type analog-to-digital conversion chip P2, an LCD (liquid crystal display), a fourth capacitor C4, a fifth capacitor C5, a second resistor R2, a first switch SW1, a third resistor R3, a fourth resistor R4, a fifth resistor R5, a sixth resistor R6, a seventh resistor R7 and a third rectifying diode VD 7.

An anode input terminal IN + of the TSC7106 type analog-to-digital conversion chip P2 is electrically connected to one end of the fourth capacitor C4 and one end of the second resistor R2, respectively, the other end of the second resistor R2 is electrically connected to one end of the first switch SW1, the other end of the first switch SW1 is electrically connected to one end of the third resistor R3 and one end of the fourth resistor R4, the other end of the third resistor R3 is electrically connected to one end of the fifth resistor R5 and one end of the fifth capacitor C5, the other end of the fifth resistor R5 is electrically connected to a cathode of the third rectifying diode VD7 after being connected IN series to the sixth resistor R6, and an anode of the third rectifying diode VD7 is used as an input terminal IN of the measurement circuit.

The other end of the fourth resistor R4 is electrically connected with one end of the seventh resistor R7, the other end of the fifth capacitor C5, the other end of the seventh resistor R7, the other end of the fourth capacitor C4 and the negative input end IN-of the TSC7106 type analog-to-digital conversion chip P2 are respectively electrically connected with the COM end of the TSC7106 type analog-to-digital conversion chip P2, and the output end of the TSC7106 type analog-to-digital conversion chip is electrically connected with the LCD.

As shown in FIG. 3, the internal circuitry of the multimeter, i.e., the measurement circuitry, is specifically set forth below:

in order to ensure the authenticity of the operation environment of the electrical examination, when the examinee measures the output voltage of the test board by using a multimeter, the voltage must be displayed as 380V, so that the most real environment simulation can be achieved.

The multimeter changes the input voltage into a number by adopting a TSC7106 type number conversion chip P2, and displays the number on an LCD display screen.

The principle is as follows: the 36V alternating voltage is rectified and divided by a third rectifier diode VD7 and voltage dividing resistors R3-R7 to obtain stable voltage, then enters the TSC7106 type analog-to-digital conversion chip P2, is subjected to internal coding processing of the TSC7106 type analog-to-digital conversion chip P2, processes and converts the measured value and outputs the value to an LCD (liquid crystal display) screen, so that the LCD screen displays a corresponding voltage value.

The reforming principle is as follows: under the condition that the circuit of the original multimeter is not changed, corresponding current can be obtained in a loop only through an internal resistor when the voltage of 380V of alternating current is measured, so that the current driving voltage is displayed, and the voltage is 380V displayed. When the resistance value of the resistor in the multimeter is reduced, and the voltage of the alternating current 36V is measured, the current passing through the resistor in the loop is not changed because the resistance value of the resistor is correspondingly reduced, and therefore the voltage display is also driven, and the displayed voltage is 380V.

The principle of the multimeter for measuring the voltage is that the current in the measuring circuit is measured, so, in the embodiment, in order to enable the multimeter to measure the 36V voltage, the voltage is still displayed as 380V, the current value measured in the multimeter needs to be kept unchanged, at this time, the resistance value in the multimeter needs to be changed, namely, the resistance values of R2-R7 in the measuring circuit are changed, the resistance in a loop is reduced in a word, after the total resistance value is changed, the voltage value after voltage division is also normalized, when the changed resistance is changed, the current in the measuring circuit is the same as the current when the 380V voltage is measured in a word, and the voltage entering the TSC7106 type number conversion chip P2 after voltage division is the same as the voltage value when the 380V voltage is measured, the 36V voltage and the 380V voltage are measured, and further the same voltage is displayed on the LCD screen, namely 380V.

In this embodiment, the total resistance in the measurement circuit is compared to the ratio of the total resistance in the circuit when measuring 380V voltage, i.e., 36: 380.

Of course, if the voltage input by the multimeter is less than 36V, the same technical effects can be achieved by changing the resistance values of R2-R7 to make the current in the measuring circuit the same as the current when the voltage of 380V is measured.

Preferably, the alternating current motor control circuit further comprises a first control circuit for controlling the alternating current motor to continuously operate, wherein the input end of the first control circuit is electrically connected with the output end of the voltage reduction circuit, and the output end of the first control circuit is electrically connected with the three-phase electric access end of the first alternating current motor M1.

The control of the continuous operation of the alternating current motor is one item in an electrician operation examination, namely, whether the wiring of the electrician for controlling the continuous operation of the alternating current motor is clear or not is examined.

The first ac motor M1 is connected to the first control circuit according to fig. 4. as shown in fig. 4, the input terminal of the first control circuit is electrically connected to three output terminals (i.e., the first output terminal U1, the second output terminal V2, and the third output terminal W3) of the step-down circuit, and the output terminal of the first control circuit is connected to the terminal of the first ac motor M1.

After the connection is finished, the second switch SB2 is pressed, the coil of the first contactor KM1 is electrified, the main contact KM11 of the first contactor KM1 is closed, the normally open auxiliary contact KM12 of the first contactor KM1 is closed, and at the moment, the first alternating current motor M1 realizes continuous rotation.

After the second switch SB2 is released and the normally open auxiliary contact KM12 is disconnected again, the first contactor KM1 continues to be powered and the first ac motor M1 is continuously operated because the normally open auxiliary contact KM12 has short-circuited the second switch SB2 when closed, so that the first control circuit remains on. This is known as self-locking.

When the third switch SB1 is pressed, the coil of the first contactor KM1 loses power, the normally open auxiliary contact KM12 is disconnected, the main contact KM11 is disconnected, and the first alternating current motor M1 stops rotating.

When the first ac motor M1 is overloaded, the first control circuit current increases, and the first thermal relay FR1 connected in series in the circuit trips because of excessive heat generated by the excessive current, and the first contactor KM1 coil in the first control circuit is de-energized, so that the first ac motor M1 stops operating. The first thermal relay FR1 is an overload protection, and the third breaker QF3 and the first fuse FU1 are short-circuit protection, and when a short circuit occurs, the circuit is blown out excessively to protect the first ac motor M1.

Preferably, the alternating current motor control circuit further comprises a second control circuit for controlling the positive and negative rotation of the alternating current motor, wherein the input end of the second control circuit is electrically connected with the output end of the voltage reduction circuit, and the output end of the second control circuit is electrically connected with the three-phase electric access end of the second alternating current motor M2.

The positive and negative rotation control of the alternating current motor is also one item of operation examination of an electrician.

As shown in fig. 5, the second ac motor M2 is connected to the output terminal of the step-down circuit in accordance with the circuit diagram given in fig. 5.

In fig. 5, the second control circuit adopts two contactors, namely a forward contactor KM2 and a reverse contactor KM3, when three pairs of main contacts KM21 of the forward contactor KM2 are electrically connected, the phase sequence of the three-phase voltage output by the step-down circuit is connected to the second alternating current motor M2 according to U-V-W.

When the three pairs of main contacts KM21 of the forward rotating contactor KM2 are turned off and the three pairs of main contacts KM31 of the reverse rotating contactor KM3 are turned on, the phase sequence of the three-phase voltage output by the step-down circuit is connected to the second alternating current motor M2 in a W-V-U manner, namely, the reverse rotation is realized.

The circuit requires that the forward contactor KM2 and the reverse contactor KM3 cannot be powered on at the same time, otherwise their main contacts will be closed at the same time, which results in a short circuit of U, W two-phase power, for this reason, a pair of auxiliary normally closed contacts of the opposite pair are connected in series with each other in the respective branches of the coils of the forward contactor KM2 and the reverse contactor KM3, i.e. KM22 and KM32 in fig. 5, an auxiliary normally closed contact KM32 of the reverse contactor KM3 in fig. 5 is connected in series with the fourth switch SB3, and an auxiliary normally closed contact KM22 of the forward contactor KM2 is connected in series with the fifth switch SB4, so as to ensure that the forward contactor KM2 and the reverse contactor KM3 cannot be powered.

In the forward starting process, the fourth switch SB3 is pressed, the coil of the forward rotation contactor KM2 is powered on, and the auxiliary normally open contact KM23 of the forward rotation contactor KM2 connected with the fourth switch SB2 in parallel is closed, so that the forward rotation contactor KM2 is continuously electrified, three main contacts KM21 of the forward rotation contactor KM2 are continuously closed, and the second alternating current motor M2 continuously and positively runs.

Stopping the process: when the sixth switch SB5 is pressed, the coil of the forward rotation contactor KM2 is deenergized, and the auxiliary normally open contact KM23 of the forward rotation contactor KM2 connected in parallel with the fourth switch SB3 is opened, so as to ensure that the forward rotation contactor KM2 is continuously deenergized, and even if the three main contacts KM21 of the forward rotation contactor KM2 are continuously opened, the second alternating current motor M2 is stopped.

And (3) reverse starting process: when the fifth switch SB4 is pressed, the coil of the counter contactor KM3 is energized, and the auxiliary normally open contact KM33 of the counter contactor KM3 connected in parallel with SB4 is closed, so as to ensure that the coil of the counter contactor KM3 is continuously energized, and further, the three main contacts KM31 of the counter contactor KM3 are continuously closed, and the second alternating current motor M2 runs in the reverse direction.

The optimized lighting device is characterized by further comprising a single-phase electric energy watchband lighting lamp wiring circuit, wherein a live wire wiring end L of the single-phase electric energy watchband lighting lamp wiring circuit is electrically connected with any one of the first output end U1, the second output end V2 and the third output end W3, and a zero line wiring end N2 of the single-phase electric energy watchband lighting lamp wiring circuit is electrically connected with the zero line output end N1.

The connection of the single-phase electric energy watchband illuminating lamp is also one of the operation examinations of electricians.

According to the circuit diagram shown in fig. 6, the electric energy meter P is connected to the step-down circuit, that is, the live wire terminal L of the single-phase electric energy watchband lighting lamp wiring circuit is electrically connected to any one of the first output terminal U1, the second output terminal V2 and the third output terminal W3 of the step-down circuit, and the zero wire terminal N2 of the single-phase electric energy watchband lighting lamp wiring circuit is electrically connected to the zero wire output terminal N1.

When the circuit is correctly wired, the illuminating lamp D can be lightened, the electric energy meter P can also work, and the circuit shown in figure 6 is the existing circuit.

As shown in fig. 7, the connection of the three-phase four-wire transformer is also an item of examination for electrician operation, the circuit of the three-phase four-wire transformer is an existing circuit, fig. 7 is a circuit diagram of a three-phase active electric meter connected through a current transformer, that is, ends 1, 4 and 7 of the electric meter are electrically connected with a three-phase voltage U phase, a three-phase voltage V phase and a three-phase voltage W phase, ends 2, 5 and 8 of the electric meter are respectively connected with an end K1 of the current transformer, and ends 3, 6 and 9 of the electric meter are respectively connected with an end K2 of. When the line connection is correct, the electric meter can work.

To sum up, adopt the utility model provides an electrician's safety operation examination equipment has following technological effect:

on one hand, the output voltage is changed into the alternating current of not higher than 36V to be used as a power supply for electrician operation, so that safety accidents can not be caused even if an operator makes misoperation when an examiner performs an operation examination, and the operation safety of the examiner is greatly improved; on the other hand, the actual values of the output voltage of the test bench measured by the voltmeter PV in the test bench and the external multimeter are 380V alternating current, so that the examiner can think that the actual values are the 380V alternating current in the real operation environment, the authenticity of the examination operation is increased, and the actual operation level of the examiner can be tested to the maximum extent.

The present invention is not limited to the above-mentioned optional embodiments, and any other products in various forms can be obtained by anyone under the teaching of the present invention, and any changes in the shape or structure thereof, all the technical solutions falling within the scope of the present invention, are within the protection scope of the present invention.

Claims

1. An electrician safe operation examination device is characterized in that: the test bench outputs alternating current lower than or equal to 36V through a voltage reduction circuit, a voltmeter (PV) is arranged on the test bench, and when the voltmeter (PV) and the multimeter are respectively and electrically connected with the output end of the voltage reduction circuit, the actual voltage of the alternating current is 380V.

2. An electrical safety operation examination device according to claim 1, wherein: the step-down circuit comprises a first Transformer (TM), a first circuit breaker (QF1) and a second circuit breaker (QF2), wherein the first circuit breaker (QF1) and the second circuit breaker (QF2) are respectively provided with three switching branches;

the input end of the first Transformer (TM) is electrically connected with 380V three-phase alternating current, and the first Transformer (TM) comprises 3 output ends which are a first voltage output end (L11), a second voltage output end (L22) and a third voltage output end (L33);

the first voltage output (L11) is connected in series with a first switching leg of the second circuit breaker (QF2) after being electrically connected to the first switching leg of the first circuit breaker (QF1), the second voltage output (L22) is connected in series with a second switching leg of a second circuit breaker (QF2) after being electrically connected to the second switching leg of the first circuit breaker (QF1), and the third voltage output (L33) is connected in series with a third switching leg of the second circuit breaker (QF2) after being electrically connected to the third switching leg of the first circuit breaker (QF 1);

the output ends of a first switch branch, a second switch branch and a third switch branch of the second circuit breaker (QF2) are respectively used as a first output end (U1), a second output end (V2) and a third output end (W3) of the voltage reduction circuit, and the voltage reduction circuit is further provided with a zero line output end (N1).

3. An electrical safety operation examination device according to claim 2, wherein: the voltmeter (PV) is connected in parallel between the first output end (U1) and the third output end (W3), a voltage stabilizing power supply circuit is arranged inside the voltmeter (PV), and two wiring ends of the voltmeter (PV) are respectively and electrically connected with the output end of the voltage stabilizing power supply circuit.

4. An electrical safety operation examination device according to claim 3, wherein: the voltage-stabilized power supply circuit comprises a second transformer (T), a rectification filtering sub-circuit, an LM317 type voltage stabilizer (V1), a first resistor (R1), an adjustable Resistor (RP), a first capacitor (C1), a second capacitor (C2), a third capacitor (C3), a first rectifying diode (VD5) and a second rectifying diode (VD 6);

one end (T1) of the second transformer (T) is electrically connected between the first switching branch of the first breaker (QF1) and the first switching branch of the second breaker (QF2), the other end (T2) of the second transformer (T) is electrically connected between the third switching branch of the first breaker (QF1) and the third switching branch of the second breaker (QF2), the output end of the second transformer (T) is electrically connected with the input end of the rectifying-filtering sub-circuit, and the output ends of the rectifying-filtering sub-circuit are respectively and electrically connected with one end of the first capacitor (C1), the negative electrode of the first rectifying diode (VD5) and the voltage input end (V11) of the LM317 type voltage stabilizer (V1);

a voltage regulation end (V12) of the LM317 type voltage stabilizer (V1) is respectively and electrically connected with one end of the adjustable Resistor (RP), one end of the first resistor (R1), one end of the second capacitor (C2) and the anode of the second rectifying diode (VD 6);

a voltage output end (V13) of the LM317 type voltage stabilizer (V1) is respectively and electrically connected with the anode of the first rectifying diode (VD5), the other end of the first resistor (R1), the cathode of the second rectifying diode (VD6) and one end of the third capacitor (C3);

the other end of the first capacitor (C1), the other end and the resistance adjusting end of the adjustable Resistor (RP), the other end of the second capacitor (C2) and the other end of the third capacitor (C3) are respectively grounded, and two terminals of the voltmeter (PV) are respectively and electrically connected with two ends of the third capacitor (C3).

5. An electrical safety operation examination device according to claim 1, wherein: a measuring circuit for measuring voltage is arranged in the multimeter, wherein the measuring circuit comprises a TSC7106 type analog-to-digital conversion chip (P2), an LCD (liquid crystal display), a fourth capacitor (C4), a fifth capacitor (C5), a second resistor (R2), a first switch (SW1), a third resistor (R3), a fourth resistor (R4), a fifth resistor (R5), a sixth resistor (R6), a seventh resistor (R7) and a third rectifying diode (VD 7);

a positive input end (IN +) of the TSC7106 analog-to-digital conversion chip (P2) is electrically connected with one end of the fourth capacitor (C4) and one end of the second resistor (R2), the other end of the second resistor (R2) is electrically connected with one end of the first switch (SW1), the other end of the first switch (SW1) is electrically connected with one end of the third resistor (R3) and one end of the fourth resistor (R4), the other end of the third resistor (R3) is electrically connected with one end of the fifth resistor (R5) and one end of the fifth capacitor (C5), the other end of the fifth resistor (R5) is electrically connected with a negative electrode of the third rectifying diode (VD7) after being connected with the sixth resistor (R6) IN series, and a positive electrode of the third rectifying diode (VD7) is used as an input end (IN) of the measurement circuit;

the other end of the fourth resistor (R4) is electrically connected with one end of a seventh resistor (R7), the other end of the fifth capacitor (C5), the other end of the seventh resistor (R7), the other end of the fourth capacitor (C4) and the negative input end (IN-) of the TSC7106 type analog-to-digital conversion chip (P2) are respectively and electrically connected with the COM end of the TSC7106 type analog-to-digital conversion chip (P2), and the output end of the TSC7106 type analog-to-digital conversion chip is electrically connected with the LCD.

6. An electrical safety operation examination device according to claim 1, wherein: the alternating current motor voltage reducing circuit further comprises a first control circuit used for controlling the alternating current motor to continuously run, wherein the input end of the first control circuit is electrically connected with the output end of the voltage reducing circuit, and the output end of the first control circuit is electrically connected with the three-phase electric access end of the first alternating current motor (M1).

7. An electrical safety operation examination device according to claim 1, wherein: the alternating current motor voltage reduction circuit further comprises a second control circuit used for controlling the positive and negative rotation of the alternating current motor, wherein the input end of the second control circuit is electrically connected with the output end of the voltage reduction circuit, and the output end of the second control circuit is electrically connected with the three-phase electric access end of the second alternating current motor (M2).

8. An electrical safety operation examination device according to claim 2, wherein: still include single-phase electric energy watchband light wiring circuit, wherein, single-phase electric energy watchband light wiring circuit's live wire wiring end (L) electricity is connected first output (U1), second output (V2) with arbitrary one in the third output (W3), the electric connection of zero line wiring end (N2) of single-phase electric energy watchband light wiring circuit zero line output (N1).

9. An electrical safety operation examination device according to claim 1, wherein: the three-phase four-wire system mutual inductor wiring control circuit is characterized by further comprising a three-phase four-wire system mutual inductor wiring control circuit, wherein the input end of the three-phase four-wire system mutual inductor wiring control circuit is electrically connected with the output end of the voltage reduction circuit.