CN2356354Y - Pocket clamp shape digital meter - Google Patents

Abstract

The utility model relates to a pocket clamp shape digital meter. A small clamp opening is adopted; an analog to digital converter chip is directly arranged on a printing plate; a function converting switch is a toggle switch composed of four sets of slide ways with four gears. One of two input inserting holes is composed of two mutually insulated conductors; the input inserting hole can control an electronic switch and can complete the functions of turning on and off the power supply, converting the items to be measured, converting the range, converting the decimal point and converting the dimension display by combining with the toggle switch. Compared with the existing clamp shape digital meter, the volume and the weight of the clamp shape digital meter reduce 2/3, the material cost reduces a half; the functions of the dimension display and the alternate current character display are increased; a buzzer circuit is also improved. The utility model is suited for being carried when an electrician goes out. The utility model is used for checking the power network line and installing, debugging and repairing the electric equipment.

Description

The pincerlike type digital watch of a kind of pocket

The utility model relates to a kind of electric instrument.

The pincerlike digital watch of existing DT-266 type is mainly used in the alternating current of measuring in electrical network and the electrical equipment, can measure alternating voltage, resistance and circuit continuity (hummer) simultaneously.Used binding clip (current transformer) the jaw diameter of this table is 10cm, and size is bigger, heaviness, and leakage field is more serious, and during measurement, when tested lead was arranged in the different position of jaw, it is bigger that reading differs, and influences measuring accuracy.It adopts the rotating disc type function knob of 16 gears to finish the function of power switch and handover measurement project, range, radix point.Rotary disk shutter contains 7 groups of slideways, and it is bigger to take the printed panel area; Simultaneously, this table has two input jacks, when measuring alternating voltage, resistance parameter, connects input jack and circuit-under-test with p-wire.Its used input jack is the porose column type conductor in a kind of centre, and whole jack is a conductor; The used A/D converter ICL7106 of this table is a dual in line integrated circuit, and volume is bigger.Its buzzer circuit is made of triode and three end piezoelectric crystals, and the oscillation frequency shakiness is easy to generate the defect of failure of oscillation.This table display dimensionless shows, and alternating current symbol reading shows not directly perceived.

The purpose of this utility model is to provide a kind of volume little, easy to carry, simple to operate, parameters such as the alternating current measured of convenient reading, alternating voltage, resistance, diode, and have the pincerlike digital watch that short circuit hummer function and radix point show, battery low-voltage shows, dimension shows, the alternating current symbol shows.It can become the electrician and carry instrument, is used for purposes such as power network line maintenance, electrical equipment installation, debugging.

The utility model is achieved in that (with reference to appended drawing)

Fig. 1 is a theory diagram of the present utility model.

Among the figure: 1. 4. 5. attenuator 6. electronic switches 7. toggle switch 8.AC/DC converter 9.A/D converters 10. comparers 11. hummers 12. LCD 13. radix point, dimension, interchange symbol driving circuit 14. data maintained switchs 15. battery low-voltage display circuits of input jack (low side) of binding clip 2. attenuators, 3. input jacks (high-end).

Binding clip (mutual inductor) (1) changes into voltage signal with tested current signal; The voltage signal decay that attenuator (2) produces current transformer is by changing the range that its damping capacity changes measured alternating current; Input jack (3) is that the input of alternating voltage, resistance, diode, short circuit hummer shelves is high-end; Input jack (4) is the input low side of alternating voltage, resistance, diode, short circuit hummer shelves, it is made of the conductor (4a, 4b) of two mutual insulatings, wherein a slice conductor (4a) connects the control end of electronic switch (6) by a resistance, another sheet conductor (4b) ground connection, when the input test line inserts jack 4, conductor (4a), (4b) connect, and make electronic switch (6) conducting, the complete machine power connection; Attenuator (5) is used for 1000 times of input voltage decay when voltage measurement, makes it drop to the following scope of 200mv; When resistance measurement, it with 10 times of the voltage drop on measured resistance decay after, supply with A/D converter (9) and use; Toggle switch (7) has 4 groups of slideways, 4 gears, and it cooperates control and the project of the measurement range of finishing electric power on/off with input jack (4), and dimension shows, the handoff functionality that radix point alternating current symbol shows; AC/DC converter (8) converts AC signal to direct current signal, A/D converter (9) is an analog to digital converter, the utility model does not adopt the dual inline type 3  position A/D converter ICL7106 (or JRC9207) of plastic package, but directly (silicon) nude film is encapsulated on the printed panel; Comparer (10) is used to control buzzer circuit (11), and when measured resistance during less than 20 Ω, comparer output noble potential makes the buzzer circuit starting of oscillation that is made of three XOR gate, sounds.LCD (12) is 3  position LCD, and it has radix point, dimension, alternating current symbol, battery low-voltage symbol; Radix point driving circuit (13) is by the control of slideway switch, and the radix point, dimension, alternating current symbol, the battery low-voltage symbol that drive LCD by different measuring function range respectively show; Data maintained switch (14) is a keyswitch, when pressing, the LCD reading is remained unchanged; Battery low-voltage display circuit (15) drops to 7.5V when following at cell voltage, makes that " LOB " character shows on the LCD, and the expression cell voltage is low excessively should give replacing.

Adopt such scheme, reduced by 12 gears than DT-266, only the function that cooperates input jack just can finish Switching Power Supply and voltage, electric current, resistance, diode, hummer with 4 gears is switched and the range conversion, diode measurement, dimension demonstration and alternating current symbol Presentation Function have also been increased simultaneously, and reduced the binding clip leakage field and improved the ac current measurement error, made hummer work more stable.It is original 1/3rd that machine volume, weight drop to, and manufacturing cost drops to 1/2nd.Easy to carry, the processing ease of the pincerlike digital watch of this pocket can be carried instrument as the electrician, is used for line maintenance, the installation of electrical equipment, debugging, maintenance.

Below in conjunction with drawings and Examples the utility model is further specified:

Fig. 2 is the circuit theory diagrams of first embodiment.

In Fig. 2, the output signal of binding clip (1) is delivered to toggle switch (7) after being decayed by attenuator (2), toggle switch (7) by 1., 2., 3., 4. 4 groups of slideways are formed, and 4 gears (I), (II), (III), (IV) are arranged, and are used for handover measurement function, range, displaying symbol; Input jack (4) by (4a) and (4b) conductor of two mutual insulatings form, wherein (4a) links to each other with electronic switch (6) Q2 base stage by a resistance R 38; Electronic switch (6) is the connection that Q2 is used to control power supply, can adopt PNP transistor or P-channel enhancement type field effect transistor, when the p-wire plug injects input jack (4), (4a) and (4b) two conductors, connect by plug conductors, making electronic switch (6) is the Q2 conducting, power connection.(II) of the toggle switch of toggle switch, (III) two grades is the current measurement shelves, and wherein (II) shelves are 20A shelves, and (III) shelves are 200A shelves; When toggle switch was in these two grades, 3. slideway was connected, power connection, and complete machine is started working, and this moment, input signal was provided through attenuator (2) by binding clip (1), and the parameter (changing R38 into 9K Ω) that changes attenuator (2) can improve range 10 times.When toggle switch places (I), (IV) two grades the time, if jack (4) does not have the p-wire plug to plug, then electronic switch (6) disconnects, and power supply turn-offs, therefore (I), (IV) two grades of functions with cut-off current shelves power supply.When input jack (3), (4) when plugging, if slideway switch (7) is in the position of (I), can carry out ac voltage measurement, input ac voltage converts direct current signal to by AC/DC converter (8) after attenuator (5) decay, be transformed into numeral by A/D converter (9) again and show; If slideway switch (7) is in the position of (IV), then complete machine is the resistance measurement shelves; The resistance measurement shelves can be used for measuring the following resistance of 2K Ω, its simultaneously can the measuring diode circuit continuity, when measured resistance less than certain value (being generally about 20 Ω), the output terminal of the comparer (10) that is made of amplifier IC3a just transfers noble potential to by electronegative potential, make hummer (11) send sound equipment, hummer is by IC2b, IC2c, and three XOR gate of IC2d and one two end formula piezoelectric crystal hummer Bz constitute.LCD (12) has 31/2 figure place sign indicating number and shows and radix point, alternating current symbol (AC), voltage dimension (V), electric current dimension (A) and battery low-voltage symbol (LOB).Two groups of slideways that radix point, dimension, alternating current symbol driving circuit (13) comprise a phase inverter Q1 and toggle switch (7) are 1.. 2.; Wherein 1. liquid crystal back electrode BP end is become after anti-phase (/BP), and for slideway 1.. 2. drive corresponding stroke and show.The battery low-voltage display circuit is made of IC2A.D7.R21, and when cell voltage was higher than 7.5V, IC2A output signal and input end be homophase 2., all be BP, when cell voltage is lower than 7.5V, IC2A output and BP anti-phase (/BP) signal shows " LOB " field of liquid crystal.It is the binding clip of φ 28mm that the utility model adopts bore, and A/D converter (9) adopts nude film JRC9207 directly to be encapsulated on the printed panel.

Second embodiment is that just can make this telogenesis is the pincerlike digital watch with real effective response after using AD/DC converter (9) instead AD736 or AD737 on first embodiment basis.

Claims (5)

1. the pincerlike digital watch of a pocket, by binding clip, attenuator, input jack (high-end), input jack (low side), attenuator, electronic switch, toggle switch, AC/DC converter, A/D converter, comparer, hummer, LCD, radix point, dimension, interchange symbol driving circuit, the data maintained switch, the battery low-voltage display circuit is formed; It is characterized in that: toggle switch is made up of 4 groups of slideways; Input jack (low side) is made of the metallic conductor of two mutual insulatings, and wherein a slice conductor dbus is crossed a resistance and is connected with an electronic switch, and another sheet conductor is received the simulation earth potential; A/D converter is to adopt nude film directly to be encapsulated on the printed panel; Hummer is made of three XOR gate and one two end piezoelectric crystal.

2. pincerlike digital watch according to claim 1, it is characterized in that electronic switch is PNP transistor (or being the P-channel enhancement type field effect transistor), transistorized emitter, collector (or the source electrode of field effect transistor, drain electrode), electronic switch joins with the Vcc of anode and circuit end respectively, and its conducting is whether by the insertion control of p-wire plug.

3. pincerlike digital watch according to claim 1 is characterized in that A/D converter adopts ICL7106 or JRC9201.

4. pincerlike digital watch according to claim 1 is characterized in that toggle switch is made up of 4 groups of slideways; Every group of slideway is made of two slideways, and 4 gears are arranged.

5. pincerlike digital watch according to claim 1 is characterized in that LCD has dimension and exchanges the symbol demonstration.

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