CN2436943Y

CN2436943Y - Tester for action current of electricity leakage protector

Info

Publication number: CN2436943Y
Application number: CN 00220862
Authority: CN
Inventors: 孙宗翰
Original assignee: Individual
Current assignee: Individual
Priority date: 2000-06-27
Filing date: 2000-06-27
Publication date: 2001-06-27
Anticipated expiration: 2010-06-27

Abstract

The utility model discloses a testing instrument pen for action current of an electricity leakage protector. An outer shell of the instrument pen is provided with a measuring range knob, a transfer switch and a plug wire hole which are respectively and correspondingly connected with a test circuit arranged in the outer shell of the instrument pen. The utility model is made into the shape of an instrument pen of a digital multimeter. An ac test stage of a digital multimeter commonly familiar to electricians is used for precisely indicating the action current of a leakage protector. The measuring accuracy of the utility model is equivalent to the measuring accuracy of the ac test stage of a digital multimeter, and the utility model is convenient for construction site test. Moreover, the test circuit does not generate interference on commercial power, and is not influenced by network voltage.

Description

Earth leakage protective device action current test test pencil

The utility model belongs to electrical instrumentation, is specifically related to a kind of earth leakage protective device action current test test pencil.

At present; earth leakage protective device is in the performance test that front and back or erecting stage action current size are installed; adopt rated resistance to substitute imaginary object of protection mostly; resistance to earth as human body; carry out earth leakage protection test, its shortcoming is that not only rated resistance is chosen difficulty, and because of the fluctuation (as the rural power grids voltage fluctuation, exchanging between the 185v-250v) of line voltage; cause test error very big, leave security incident hidden danger easily.For example: its actual action current I=30mA of a certain earth leakage protective device, by standard civil power u=220v, choosing rated resistance is R=220/0.03=7333 Ω so; As the civil power u that upwards fluctuates ¹During=250v, the electric leakage that rated resistance produces is over the ground flowed and is: I ¹=u ¹/ R=250/7333=34.1mA; As the civil power u that fluctuates downwards ¹¹During=185v, the leakage current that rated resistance produces over the ground is: I ¹¹=u ¹¹/ R=185/7333=25.2mA; The test error that produces because of voltage ripple of power network is respectively: Φ ¹=1I ¹-I1=134.1-301=4.1mA, Φ ¹¹=1I ¹¹-I1=125.2-301=4.8mA.

The purpose of this utility model is: designs a kind of tester for action current of electricity leakage protector, solves the accurate test that earth leakage protective device is installed front and back or erecting bed action current size, and the convenient construction on-the-spot test, and also test is not limited by line voltage.

The purpose of this utility model is achieved in that this test test pencil makes digital multimeter test pencil shape, and the alternating-current measurement shelves that utilize the electrician generally to be familiar with the digital multimeter of usefulness are indicated the earth leakage protective device action current; The test circuit that is made in the test pencil shell is connected respectively range knob, change-over switch and the plug wire hole that arranges on the test pencil shell; Test circuit is partly connected to form by bridge rectifier part and composite amplifier; Commutation diode (or by the replacement of bridge heap) forms rectifying part, and two ac input ends are wherein arranged, and a termination enters digital multimeter black meter pen position, and another termination crocodile clip inserts the earth, also has simultaneously two output positive and negative terminals; T ₁T ₂Form the common collector composite amplifier, T ₁For promoting pipe, T ₂Be amplifier tube, T ₁Emitter stage insert T ₂Base stage, R ₁As load resistance, a termination enters the output plus terminal of rectifying part, a termination T ₁T ₂Common collector, filter capacitor C ₁Anode and Z ₁Z ₂Negative pole also insert common collector, R ₂Seal in T as negative feedback resistor ₂Emitter stage; Change-over switch K bipod pin order is respectively abcd and a ¹b ¹c ¹d ¹, the k set only has ab and a ¹b ¹Connect, k puts " 2 " and only has bc and b ¹c ¹Connect, k puts " 3 " and only has cd and c ¹d ¹Connect; Two inputs of rectifying part insert respectively the cd pin of k, z ₁Positive pole insert the c of k ¹Pin, z ₂Positive pole seal in R ₃The a of rear access k ¹Pin, the slide of potentiometer w inserts T ₁Base stage, potentiometer one termination enters the b of k ¹Pin, the other end of potentiometer and R ₂An end, filter capacitor C ₁Negative terminal jointly insert rectification output negative terminal.

Introduce embodiment of the present utility model below in conjunction with accompanying drawing:

Fig. 1 is used for the synoptic diagram of action current test for the utility model

Fig. 2 is the utility model circuit diagram

Fig. 3 is another embodiment circuit diagram of the utility model

Among the figure: 1 earth leakage protective device, 2 digital multimeter, 3 test test pencils, 4 test pencil shells, 5 range knobs, 6 switches, 7 plug wire holes.

As shown in Figure 1; test test pencil 3 is connected the accurate test that is used for earth leakage protective device action current size through plug wire hole 7 with earth leakage protective device 1, digital multimeter 2, range knob 5, switch 6 and the jack 7 that is provided with on its test pencil shell 4 is corresponding respectively to be connected on the test circuit that is positioned at the test pencil shell.

Test circuit is partly connected to form by bridge rectifier part and composite amplifier; As shown in Figure 2, by D ₁, D ₂, D ₃, D ₄4 commutation diodes (or being replaced by the bridge heap as shown in Figure 3) form rectifying part, and two ac input ends are wherein arranged, and a termination enters digital multimeter black meter pen position, and another termination crocodile clip inserts the earth, also has simultaneously two output positive and negative terminals; T ₁T ₂Form the common collector composite amplifier, T ₁For promoting pipe, T ₂Be amplifier tube, T ₁Emitter stage insert T ₂Base stage, R ₁As load resistance, a termination enters the output plus terminal of rectifying part, a termination T ₁T ₂Common collector, filter capacitor C ₁Anode and Z ₁Z ₂Negative pole also insert common collector, R ₂Seal in T as negative feedback resistor ₂Emitter stage; Change-over switch K bipod pin order is respectively abcd and a ¹b ¹c ¹d ¹, the k set only has ab and a ¹b ¹Connect, k puts " 2 " and only has bc and b ¹c ¹Connect, k puts " 3 " and only has cd and c ¹d ¹Connect; Two inputs of rectifying part insert respectively the cd pin of k, z ₁Positive pole insert the c of k ¹Pin, z ₂Positive pole seal in R ₃The a of rear access k ¹Pin, the slide of potentiometer w inserts T ₁Base stage, potentiometer one termination enters the b of k ¹Pin, the other end of potentiometer and R ₂An end, filter capacitor C ₁Negative terminal jointly insert rectification output negative terminal.

Each component parameters: D ₁D ₂D ₃D ₄Be 4 (IN4007) commutation diodes, R ₁Be 450 Ω/45w resistance (can be substituted by three 150 Ω/15w cement electricity group), R ₂Be 150 Ω/15w cement resistor, R ₃Be the metalfilmresistor of 200k Ω/(1/2w), C ₁Be 10uF/400v electrochemical capacitor, Z ₁Be 30v Zener diode, Z ₂Be the 50V Zener diode, w is the capacitor of 22k Ω/(1/2w), and k is the two group of third gear slip change-over switch (totally 8 pins), T ₁T ₂Be respectively 2sc2073 and 2sc5270NPN type transistor (installing 20 * 30 * 0.5mm aluminium heat sink during installation additional), the withstand voltage 300v of crocodile clip gum cover.

This test test pencil operation principle: when the K set, be little current gear, can carry out the test of earth leakage protective device action current.After civil power inserted earth leakage protective device, the output live wire entered this test circuit to big ground voltage behind digital multimeter alternating-current measurement shelves.

This voltage at first passes through bridge rectifier, forms the DC voltage of pulsation at the output positive and negative terminal of bridge rectifier.Through R ₁To filter capacitor C ₁Charging is if w is threaded onto " Min ", T ₁T ₂The common collector composite amplifier that forms is not worked Z ₂, R ₃, w is C ₁Discharge loop is provided.If civil power is 220v, the test leakage current of digital multimeter indication this moment is 3.9mA (omitting theoretical calculating).If w rotation direction " Max ", Z ₂, R ₃, the bias loop formed of w, make T ₁Base potential progressively raise T ₁T ₂Base current progressively increase T ₁-T ₂Progressively enter magnifying state, through R ₁, T ₁, T ₂, R ₂The C that forms ₁Discharge current also progressively increases, and the leakage current that whole test circuit produces is also increasing.If w is threaded to " Max ", if being 220v, civil power exchanges, this moment, the test leakage current of digital multimeter indication was 96mA (omitting Theoretical Calculation).

When k places " 2 ", to use as the adjustable interchange Constant Current Load of big electric current, digital multimeter must place the high-current test shelves.Principle of work is the same.Exchange if civil power is 220v, when w was threaded onto " Min ", digital multimeter indication test leakage current was 6.7mA (omitting Theoretical Calculation), when w is threaded onto " Mux ", is designated as 300mA (omitting Theoretical Calculation)

Z in the circuit ₂Setting acquire a special sense, one is T ₁T ₂Base stage protection is provided, and it two is T ₁T ₂The standard bias voltage is provided, makes the sampling voltage of w that reliable scope be arranged.Its three, and T ₂The emitter-base bandgap grading negative feedback resistor rise simultaneously and stablize T ₁T ₂The effect of quiescent point.

R in the circuit ₃Be current-limiting resistance, restricted T ₁T ₂Maximum On current, guarantee that the little current gear of digital multimeter is not burnt.

When K placed " 3 ", whole test circuit was not worked, and test pencil can be used as the conventional pen use simultaneously.

This test test pencil operating procedure:

(1) puts k in " 1 "

A. search the label of tested earth leakage protective device action current, the red test pencil of digital watch inserts " A ", and correspondingly the range knob places little current gear, and the AC/DC switch places the AC position.

B. the test circuit test pencil is inserted digital watch COM hole, the ground connection crocodile clip inserts the earth (as being clipped on the object such as running water pipe), and w is threaded to " Min " position.

C. red test pencil is inserted on the live wire of tested protector output terminal (L end), or insert the live wire (L end) of the supply socket of protector output terminal, and w is rotated to " Max " direction.Observe the saltus step of gauge outfit registration.

When d. protector moved, the registration maximal value of digital watch was the actual act electric current of protection.

(2) put k in " 2 "

When a. doing the test of big electric current adjustable constant-flow source, the red test pencil of digital watch inserts big current aperture, and as " 10A ", correspondingly the range knob places big current gear, and the AC/DC switch places the AC position.

B. other step is the same.

(3) put k in " 3 "

This test this moment test pencil uses and is equal to the general black meter pen of digital watch.Repeat no more in addition.

This test test pencil test specification:

(1) putting k is 3.9mA-96mA in " 1 " test specification

(2) putting k is 6.7mA-300mA in " 2 " test specification

The utlity model has following advantage:

1, utilizes the electrician generally to be familiar with the alternating-current measurement shelves of the digital multimeter of use, come Accurately indicate the earth leakage protective device action current, measuring accuracy is equal to the friendship of digital multimeter Stream testing current shelves precision, economy is again accurate.

2, test circuit is made into test pencil, the convenient construction on-the-spot test.

3, be provided with third gear switch k; make test test pencil () can do the earth leakage protective device performance test of little range, (two) can do the adjustable constant-flow source of wide range again, are used for other test; (3) simultaneously, can make the test test pencil be used as the common black meter pen of digital multimeter uses.

4, test circuit design does not produce civil power and disturbs.

5, not influenced by voltage ripple of power network.

Claims

1, earth leakage protective device action current test test pencil is characterized in that: range knob (5), switch (6) and plug wire hole (7) are set, the corresponding respectively test circuit that is positioned at test pencil shell (4) that connects on its test pencil shell (4).

2, tester for action current of electricity leakage protector according to claim 1 is characterized in that: test circuit is partly connected to form by bridge rectifier part and composite amplifier; Commutation diode or replaced forming rectifying part by bridge heap, wherein: two ac input ends are arranged, and a termination enters digital multimeter black meter pen position, and another termination crocodile clip inserts the earth, also has simultaneously two to export positive and negative terminals; T ₁T ₂Form the common collector composite amplifier, T ₁For promoting pipe, T ₂Be amplifier tube, T ₁Emitter stage insert T ₂Base stage, R ₁As load resistance, a termination enters the output plus terminal of rectifying part, a termination T ₁T ₂Common collector, filter capacitor C ₁Anode and Z ₁Z ₂Negative pole also insert common collector, R ₂Seal in T as negative feedback resistor ₂Emitter stage; Change-over switch K bipod pin order is respectively abcd and a ¹b ¹c ¹d ¹, the k set only has ab and a ¹b ¹Connect, k puts " 2 " and only has bc and b ¹c ¹Connect, k puts " 3 " and only has cd and c ¹d ¹Connect; Two inputs of rectifying part insert respectively the cd pin of k, z ₁Positive pole insert the c of k ¹Pin, z ₂Positive pole seal in R ₃The a of rear access k ¹Pin, the slide of potentiometer w inserts T ₁Base stage, potentiometer one termination enters the b of k ¹Pin, the other end of potentiometer and R ₂An end, filter capacitor C ₁Negative terminal jointly insert rectification output negative terminal.