CN102636724B - Portable multi-functional serial crosstalk detector - Google Patents

Abstract

The invention relates to a portable multi-function serial current detector, which is suitable for detecting faults of alternating current and direct current hybrid connections in substations. The present invention includes a shell and a non-contact electric test unit; the non-contact electric test unit includes a pair of electromagnetic induction sheets, an AC voltage amplifier, a drive and sound and light alarm circuit, a single-pole three-throw switch SA and a battery E; One end of a pair of electromagnetic induction sheets is connected in parallel to the input end of the AC voltage amplifier, the output end of the AC voltage amplifier is connected to the input end of the drive and sound and light alarm circuit, and the battery E is respectively connected to the At the power supply end of the AC voltage amplifier and drive and sound and light alarm circuit. The invention has the advantages of high sensitivity, simple operation, convenient portability, accuracy and reliability.

Description

Portable Multifunctional Series Electricity Detector

technical field

The invention relates to a portable multi-functional series power detector, which is suitable for detecting faults of AC and DC hybrid connections in substations.

Background technique

Infrastructure substations have the problem of AC and DC hybrid connections, especially in 500kV ultra-high voltage substations. There are many secondary cables in the protection screen cabinet, terminal box and control cabinet, and the secondary wiring on the terminal block is densely packed. Large, and especially important, a slight negligence will affect the normal power transmission and bring hidden dangers to the stability of the power grid. The current method of checking and processing the mixed connection of AC and DC uses secondary drawings to check the lines on the drawings, which is time-consuming and laborious.

When measuring with a multimeter, there are also problems with the mixed use of AC and DC voltage files: (1) When measuring DC voltage with AC voltage files, the voltmeter may have no reading or be twice as high as the actual DC voltage. The specific error is half-wave with the rectification in the meter It's still about the whole wave. In short, the value of the table is meaningless. (2) The DC voltage range measures the AC voltage. Due to the frequency, it will affect the swing rate of the pointer, and long-term use will cause damage to the multimeter.

Contents of the invention

The technical problem to be solved by the present invention is to provide a portable multi-function serial current detector with high sensitivity, simple operation, convenient portability, accuracy and reliability.

The present invention adopts following technical scheme:

The present invention includes a shell and a non-contact electric test unit; the non-contact electric test unit includes a pair of electromagnetic induction sheets, an AC voltage amplifier, a drive and sound and light alarm circuit, a single-pole three-throw switch SA and a battery E; One end of a pair of electromagnetic induction sheets is connected to the input end of the AC voltage amplifier in parallel, the output end of the AC voltage amplifier is connected to the input end of the drive and sound and light alarm circuit, and the battery E is respectively connected to At the power supply end of the AC voltage amplifier and drive and sound and light alarm circuit.

The non-contact electric testing unit also includes a lighting circuit, and the power supply end of the lighting circuit is connected to the battery E through a single-pole three-throw switch SA.

The portable multi-functional series electric detector also includes a contact-type electric test unit, and the contact-type electric test unit includes a screwdriver sensor, a rectifier circuit, first to third amplified light alarm circuits and a button switch SB;

The rear end of the metal rod of the screwdriver sensor is connected to the input end of the rectification circuit, the output ends of the rectification circuit are respectively connected to the input ends of the first to third amplified light alarm circuits, and the battery E is respectively connected to the The power terminals of the first to third amplified light alarm circuits.

The positive effect of the present invention is as follows:

(1) The present invention greatly improves the work efficiency of the infrastructure inspection of the secondary circuit, which is more convenient and time-saving than the previous method of checking the line on the map, and most importantly, it is more accurate and reliable. In the past, it took 2 people/day to find out whether a 500kV line switch control cabinet and terminal box are in series. After using this series detector, it takes 1 person/half a day to complete it efficiently. Greatly save manpower, material and financial resources.

(2) The present invention also has the characteristics of high sensitivity, convenient operation, convenient portability, accuracy and reliability.

In addition to checking the AC and DC series connection problems, this detector also has the following uses:

(1) Can easily judge whether the 60V ~ 220V AC power line is live;

(2) Measure the level of AC voltage within a certain range;

(3) It is convenient to determine the breaking position of the wire core.

Description of drawings

Accompanying drawing 1 is the principle block diagram of embodiment 1 of the present invention (using non-contact electric testing unit).

Accompanying drawing 2 is the schematic circuit diagram of Fig. 1.

Accompanying drawing 3 is the principle block diagram of the contact type electric test unit.

Accompanying drawing 4 is the schematic circuit diagram of Fig. 3.

Fig. 5 is a front view of the casing of the present invention.

Fig. 6 is a rear view of the housing of the present invention.

In Fig. 1-6, 1 electromagnetic induction sheet, 2 electromagnetic induction sheet, 3 screwdriver sensor, 4 housing, 5 second to fourth light-emitting diodes LED2-LED4 glass screen with numbers, 6 buttons Switch (SB), 7 single-pole three-throw switch (SA), 8 self-concentrating lighting bulb (DL), 9 battery box cover, 10 speaker sound hole, 11 first light-emitting diode (LED1).

Detailed ways

Example 1 (contains only non-contact electrometry unit, see Figure 1, Figure 2, Figure 5 and Figure 6):

The present embodiment includes a housing 4 and a non-contact electric test unit; the non-contact electric test unit includes a pair of electromagnetic induction sheets 1, 2, an AC voltage amplifier, a drive and sound and light alarm circuit, a single-pole three-throw switch SA and Battery E; one end of the pair of electromagnetic induction sheets 1, 2 is connected in parallel to the input end of the AC voltage amplifier, the output end of the AC voltage amplifier is connected to the input end of the drive and sound and light alarm circuit, and the battery E The single-pole three-throw switch SA is respectively connected to the power supply end of the AC voltage amplifier and the drive and sound and light alarm circuit.

The structure of the pair of electromagnetic induction sheets 1 and 2 is the same, and both are copper sheets of 5×10×0.5 mm.

The AC voltage amplifier is composed of an N-channel field effect transistor VT1 and a resistor R1; the gate g of the N-channel field effect transistor VT1 is connected to the parallel terminals of the pair of electromagnetic induction sheets 1 and 2, and its drains d are in turn Connect the positive pole of the battery E through the resistor R1 and the single-pole three-throw switch SA, and connect the source s to the negative pole of the battery E;

The drive and sound and light alarm circuit is composed of transistors VT2-VT3, resistors R2-R3, first light-emitting diode LED1 and speaker HA; the base of transistor VT2 is connected to the drain d of N-channel field effect transistor VT1 through resistor R1, and the transistor The collector of VT2 is connected to the positive pole of the battery E through the single-pole three-throw switch SA, the emitter of the transistor VT2 is connected to the base of the transistor VT3, the emitter of the transistor VT3 is connected to the negative pole of the battery E, and the collector of the transistor VT3 passes through the resistor R3 and the first pole in turn. A light-emitting diode LED1, a speaker HA and a single-pole three-throw switch SA are connected to the positive pole of the battery E.

The non-contact electric testing unit also includes a lighting circuit, and the power supply end of the lighting circuit is connected to the battery E through a single-pole three-throw switch SA.

The lighting circuit is composed of self-concentrating bulbs DL.

The housing 4 is in the shape of an inverted "T", and the pair of electromagnetic induction sheets 1 and 2 are symmetrically installed in both ends of the horizontal arm at the lower end of the inverted "T"-shaped housing.

The working principle of embodiment 1 is as follows:

When a pair of electromagnetic induction sheets is close to the AC-DC hybrid circuit, the alternating magnetic field generated by the AC voltage acts on the pair of electromagnetic induction sheets, which is similar to cutting the magnetic induction line, so that an induced electromotive force is generated on the pair of electromagnetic induction sheets, so that As soon as the AC voltage signal is captured, the closer the pair of electromagnetic induction sheets are to the charged body, the more sensitive they are, and the greater the induced electromotive force generated.

The N-channel field effect transistor VT1 is a voltage control element, and its input impedance is relatively high. As long as a variable voltage is applied to the input gate, the change of the output current can be controlled, and it is particularly sensitive to the change of the 50Hz power frequency voltage. When a pair of electromagnetic induction plates has no induced electromotive force, VT1 is in a zero-bias state. Since VT1 is a depletion type, its drain d and source s are always in a saturated conduction state, and the bias voltage obtained by the base of VT2 through R2 is low. At 0.65V, VT2 and VT3 are in the cut-off state. When a pair of electromagnetic induction chips senses a weak AC voltage, after being amplified by VT1, an amplified 50Hz AC voltage signal will be output from its drain d, so that VT2 and VT3 are also continuously turned on and off at the same frequency.

When the transistor VT3 is turned on, the speaker HA is driven to emit continuous sound, and LED1 is lit to remind people that there is an AC voltage detected at a pair of electromagnetic induction plates.

When the SA switch of the single-pole three-throw switch is at the 1 position, the non-contact electrometry unit is started; when the SA is at the 2 position, it is in the off state, and the detector does not consume power; when the SA is at the 3 position, the lighting circuit is started, both It can be used for short-term lighting at night, and it can also illuminate the secondary circuit when repairing electrical devices.

Example 2 (contains both non-contact and contact electric testing units, see Figure 1-6):

The difference between embodiment 2 and embodiment 1 is that it also includes a contact type electric test unit, which includes a screwdriver sensor 3, a rectifier circuit, first to third amplified light alarm circuits and a button switch SB;

The rear end of the metal rod of the screwdriver sensor 3 is connected to the input end of the rectification circuit, and the output ends of the rectification circuit are respectively connected to the input ends of the first to third amplified light alarm circuits. Connect the power supply terminals of the first to third amplified light alarm circuits.

The screwdriver sensor 3 is a "one" or "ten" screwdriver; the metal rod rear end of the screwdriver.

The first to third amplified light alarm circuits are composed of transistors VT4-VT6, potentiometers RW1-RW3, resistors R4-R6, capacitors C1-C3 and second to fourth light-emitting diodes LED2-LED4;

The structures of the first to third amplified light alarm circuits are the same, wherein the first amplified light alarm circuit is composed of transistor VT4, potentiometer RW1, resistor R4, capacitor C1 and the second light emitting diode LED2; the base of the transistor VT4 The negative pole of the rectifier diode D is connected via the potentiometer RW1, the emitter of the transistor VT4 is connected to the negative pole of the battery E, and the collector of the transistor VT4 is sequentially connected to the second light-emitting diode LED2, the resistor R4, and the button switch SB. the positive pole of the battery E;

The bases of the VT5-VT6 are respectively connected to the cathodes of the rectifier diodes via the potentiometers RW2 and RW3.

The screwdriver sensor 3 is fixed on the upper end of the inverted "T" shaped housing.

The working principle of the contact type electrometer unit in embodiment 2 is as follows:

The flat-head screwdriver 3 of about 55mm can be used as a screwdriver and also as a contact probe at the same time. It can be directly contacted with the charged body, but the housing 4 should be insulated.

When the button switch SB is pressed, the screwdriver sensor 3 is contacted with an unknown AC power source, and the AC power is rectified by the rectifier diode D, and then input to the first to third amplification and sound alarm circuits. Adjust the resistance values of RW1, RW2 and RW3 according to the voltage to be measured (when the power supply is disconnected). After debugging, if VT4 is on and LED2 is on, the measured voltage is ≤60V; if VT4~VT5 is on , LED2~LED3 lights up, the measured voltage is about 110V; if VT4~VT6 is turned on, LED2~LED4 lights up, then the measured voltage is ≥220V.

The glass screen 5 with digital characters displays three values of 60V, 110V, and 220V in sequence according to the measured AC voltage. When the AC signal is less than 60V, only the word 60V lights up, and the brightness is weak; when the AC signal is greater than 220V , the three words 60V, 110V, and 220V are all bright, and the brightness is relatively strong. R4~R6 are the current limiting resistors of LED2-LED4, which limit the current within the rated value of 15-20mA. Capacitors C1-C3 are anti-interference capacitors. The resistance values of RW1～RW3 and R4-R6 are all debugged when the power supply is disconnected.

The invention can detect whether the AC power line is electrified at a distance of 2cm to 15cm from the tested AC power line. When using its non-contact electrical inspection function, move slowly from top to bottom along the terminal row at a distance of 6cm from the secondary wiring of the terminal row. When the sound and light alarm, it means that there is an AC voltage here. At this time, compare the line number and Check whether the drawings are consistent, and use the other end of the detector to start the contact electric test function to further judge which cable core is charged and measure the amplitude of the AC voltage carried. When detecting whether the AC and DC are mixed, disconnect the circuit breakers of each DC circuit and only close the circuit breaker of the AC circuit, so that the detection effect is better.

This detector can also detect the broken end position of the wire core, as long as the 220V voltage is applied to the tested wire core, the detector is close to the tested line, the speaker makes a sound, and the light-emitting diode LED1 emits light, and then along the length direction of the line Move gradually, checking as you go. The place where LED1 goes out is the definite part of broken core.

Claims (1)

1. A portable multifunctional series electric detector, characterized in that it includes a housing (4) and a non-contact electric test unit; the non-contact electric test unit includes a pair of electromagnetic induction sheets (1, 2), an AC Voltage amplifier, drive and sound and light alarm circuit, single-pole three-throw switch SA and battery E; one end of the pair of electromagnetic induction sheets (1, 2) is connected in parallel to the input end of the AC voltage amplifier, and the AC voltage amplifier The output end of the battery E is connected to the input end of the drive and sound and light alarm circuit, and the battery E is respectively connected to the AC voltage amplifier and the power supply end of the drive and sound and light alarm circuit through the single-pole three-throw switch SA; The pair of electromagnetic induction sheets (1, 2) have the same structure, both of which are 5×10×0.5mm copper sheets; The AC voltage amplifier is composed of an N-channel field effect transistor VT1 and a resistor R1; the gate g of the N-channel field effect transistor VT1 is connected to the parallel terminals of the pair of electromagnetic induction sheets (1, 2), and its drain d is connected to the positive pole of the battery E through the resistor R1 and the single-pole three-throw switch SA in turn, and its source s is connected to the negative pole of the battery E; The drive and sound and light alarm circuit is composed of transistors VT2-VT3, resistors R2-R3, first light-emitting diode LED1 and speaker HA; the base of transistor VT2 is connected to the drain d of N-channel field effect transistor VT1 through resistor R1, and the transistor The collector of VT2 is connected to the positive pole of the battery E through the single-pole three-throw switch SA, the emitter of the transistor VT2 is connected to the base of the transistor VT3, the emitter of the transistor VT3 is connected to the negative pole of the battery E, and the collector of the transistor VT3 passes through the resistor R3 and the first pole in turn. A light-emitting diode LED1, a speaker HA and a single-pole three-throw switch SA are connected to the positive pole of the battery E; The non-contact electric testing unit also includes a lighting circuit, the power supply end of the lighting circuit is connected to the battery E through a single-pole three-throw switch SA; The lighting circuit is composed of self-concentrating bulbs DL; The casing (4) is in the shape of an inverted "T", and the pair of electromagnetic induction sheets (1, 2) are symmetrically installed in both ends of the horizontal arm at the lower end of the inverted "T"-shaped casing; The portable multifunctional series current detector also includes a contact-type electric test unit, and the contact-type electric test unit includes a screwdriver sensor (3), a rectifier circuit, first to third amplified light alarm circuits and a button switch SB; The rear end of the metal rod of the screwdriver sensor (3) is connected to the input end of the rectification circuit, and the output ends of the rectification circuit are respectively connected to the input ends of the first to third amplified light alarm circuits, and the battery E is switched by a button. SB is respectively connected to the power supply terminals of the first to third amplified light alarm circuits; The screwdriver sensor (3) is a "one" or "ten" screwdriver; The rectification circuit is composed of a rectification diode D; the anode of the rectification diode D is connected to the metal rod rear end of the screwdriver; The first to third amplified light alarm circuits are composed of transistors VT4-VT6, potentiometers RW1-RW3, resistors R4-R6, capacitors C1-C3 and second to fourth light-emitting diodes LED2-LED4; The structures of the first to third amplified light alarm circuits are the same, wherein the first amplified light alarm circuit is composed of transistor VT4, potentiometer RW1, resistor R4, capacitor C1 and the second light emitting diode LED2; the base of the transistor VT4 The negative pole of the rectifier diode D is connected via the potentiometer RW1, the emitter of the transistor VT4 is connected to the negative pole of the battery E, and the collector of the transistor VT4 is sequentially connected to the second light-emitting diode LED2, the resistor R4, and the button switch SB. the positive pole of the battery E; The bases of the VT5-VT6 are respectively connected to the cathodes of the rectifier diodes via the potentiometers RW2 and RW3; The screwdriver sensor (3) is fixed on the upper end of the inverted "T"-shaped housing.