KR940006504Y1 - Alarm apparatus of current resistance and voltage tester - Google Patents

Abstract

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Description

Alarm device for current, resistance and voltage tester

1 is a front view of the tester incorporating the present invention.

Figure 2 is a cross-sectional view taken along the line A-A of Figure 1 showing the detection switch portion of the device of the present invention.

3 is a circuit diagram of the present invention.

* Explanation of symbols for main parts of the drawings

1: Tester 4: Rotary Selector

5: jack 5a: pin

5b: Sleeve 6-9: Socket

6a-9a: Socket housing 6b-9b: Socket body

17 measurement circuit 30 first detection switch

31: second detection switch 31a: fixed contact

31b: Movable contact 34: Movable ground contact

35: movable contact portion 36: upper outward curved portion

37: inward protrusion 38A, 38B: contact operation pin

The present invention relates to an alarm device of a tester for measuring current, resistance, and voltage (hereinafter referred to as a tester), and particularly, an insertion position of a jack configured at the tester's section position and the rear end of the measuring probe and inserted into the socket of the tester main body. Does not coincide with the alarm, and the alarm device of the tester for current, resistance and voltage measurement that protects the measuring circuit built in the tester by generating a warning sound and allowing the user to insert the jack into the correct socket. .

In general, the tester can select the measurement position so that the selector measures AC current, AC current, DC current, battery voltage, BAT, resistance, OHM, DC voltage and ACV. One of the two measurement probes allows the jack configured at the rear end to be inserted into the common ground terminal socket of the tester, and the other measurement probe has the voltage and resistance for the voltage and resistance measurement. It is inserted into the (V / Ω) socket and used to measure the unit current (A) or current (10A) in units of 10 multiples.

However, the user tried to measure the voltage in a circuit of an electrical and electronic device by using a tester, but inadvertently or unintentionally inserted the jack of the measuring probe into the current measuring socket and placed the selector in the voltage or resistance measuring position. In the case of measuring the voltage of a circuit with a woofer, there is a possibility that the circuit built in the tester may be damaged.

In view of the above, there have been some cases in which a socket for inserting a jack of a measuring probe is selectively opened and closed, and a circuit for detecting that the probe jack is inserted into a correct socket has been introduced. In this case, there is a hassle to open and close the socket artificially, and in the latter case, the purpose is to allow complete electrical coupling to the socket of the jack.

In the present invention, in view of such a conventional point of view, when the jack of the measuring probe is inserted into the current measuring socket, it is measured when the selector is in the voltage or resistance measuring position before the measuring probe is measured. It is to prevent the inadvertent damage of the circuit inside the tester before the actual circuit measurement by generating an alarm sound indicating that the jack of the probe is incorrectly plugged in. same.

1 is a front view of the tester (1) incorporating the alarm device of the present invention, a rotary selector (4) with a handle (3) marked with a jik (2) in the center is installed and the measurement probe (shown below) Current measuring socket (6), single-unit current measuring socket (7), common ground terminal socket (8) and battery voltage into which the jack 5 (Fig. 2) of the A voltage and resistance measuring socket 9 including a lamp is arranged and installed. On the upper side, a display 10 indicating a measured value is arranged. On one side, a transistor socket 11 for checking the polarity of the transistor, etc. is provided. It is arranged.

The functional part of the tester 1 is known, and the user can insert the jack into the common grounding terminal socket 8 of the two measuring probes, and the other measuring probe The socket 5 of the target to be measured, for example, the voltage and resistance measurement socket 9 to measure the voltage and resistance, or the current measurement socket ( 6) Alternatively, insert the current measuring socket (7) and rotate the rotary selector (4) so that the guide (2) is placed on the periphery of the rotary selector (4). The measurement range is indicated in the table (12), the battery voltage measurement range table (13), the resistance measurement range table (14), the DC voltage measurement range table (15), and the AC voltage measurement range table (16). When you measure a circuit that you want to measure with a probe, the measured value It is reminded other.

The electrical measuring circuit 17 of such a tester 1 is also known, and shows a dashed line in FIG. 3, and each socket is well known to those skilled in the art. Connected input protection circuit 18, function / range switch assembly 19, transistor test circuit 20, diode and contact test circuit 21, voltage divider 22, classifier 23, divider 24, die It is composed of the derby / beeper 25, an AC-DC converter 26, a function / range switch assembly 27, an AD converter 28, and an LCD display 29.

The alarm device according to the present invention, as shown in Figure 3, the first detection switch 30, the rotary selector installed between the single unit current measuring socket 7 and the current measuring socket 6 of 10-fold unit ( The second detection switch 31, the comparison discriminating portion 32, and the beeper sound generating portion 33, which are installed at 4).

The first detection switch 30 is configured to be opposed to the movable ground contact piece 34 and the movable contact piece 35 as shown in detail in FIG. 2 for its mechanical configuration. It is installed in between.

On the other hand, as shown in Figs. 1 and 2, each socket 6-9 is composed of a socket body 6b-9b installed in the socket housing 6a-9a, and the measurement probe The jack 5 is composed of a central pin 5a and a sleeve 5b surrounding it. Therefore, when the jack 5 is inserted into the socket 6-9, the pin 5a is inserted into the socket tube 6b-9b and the sleeve 5b is a socket outside the socket tube 6b-9b. It is inserted into the housing 6a-9a.

Again, returning to the first detection switch 30, as mentioned above, the first detection switch 30 is a movable contact contact piece 34 and a movable contact which are mounted between two storage measuring sockets 6 and 7, respectively. It consists of a piece 35. On the outside of the contact pieces 34 and 35, the upper outwardly curved portion 36 is connected to the socket body 6b and 7b through the socket housings 6a and 7a of the respective current measuring sockets 6 and 7. The contact working pieces 38A and 38B in contact with each other and the inwardly projecting parts 37 in contact with the respective contact pieces 34 and 35 in the middle thereof are connected to the circuit board 39 together with the respective contact pieces 34 and 35 at the lower end thereof. ) Is supported.

Therefore, when the jack 5 of the measuring probe is inserted into the current measuring socket 6 or 7, the sleeve 5b of the jack 5 is connected to the socket outside the socket body 6b and 7b. Inserted into the housings 6a and 7a, the upper outwardly curved portion 36 of the contact actuating pieces 38A and 38B is moved toward the contact pieces 34 and 35, so that the inwardly projecting part 37 is connected to the contact piece 34. ) Or (35) to the other side so that the contact pieces 34 and 35 can be contacted.

In the alarm device according to the present invention, the movable ground contact piece 34 of the first detection switch 30 is grounded and the movable contact piece 35 is connected to the second detection switch 31. The second detection switch 31 has an arc shape in a range corresponding to the battery voltage measurement range table 13, the resistance measurement range table 14, the DC voltage measurement range table 15, and the AC voltage measurement range table 16. It is composed of a fixed contact 31a arranged in the rotary selector 4 and a movable contact 31b which rotates with it. The movable contact piece 35 of the first detector 30 is connected to the fixed contact 31a of the second detection switch 31. However, the movable contact piece 35 of the first detector 30 may be connected to the movable contact 31b of the second detection switch 31 by a method other than the illustrated example.

On the other hand, the second detection switch 31 is connected to the inverting input of the comparator IC ₁ through the current limiting resistor R ₂ to which the power supply voltage V + is applied through the pull-up resistor R ₁ . The divider inputs R ₃ and R ₄ are connected to the inverse input of the comparator IC ₁ . Comparator IC ₁ constitutes the above-mentioned comparison discrimination section 32. The output of the comparator IC ₁ is connected to the NAND gates G ₁ -G ₃ constituting the oscillation circuit, the NAND gate G ₄ constituting the amplification part is connected to the NAND gate G ₃ , and the buzzer BZ is connected to the output side thereof. The NAND gates G ₁ -G ₄ and the capacitor C ₁ , the resistors R ₅ , R _{6, which} are the oscillation constant elements, constitute the beeper sound generator 33.

The operation of the present invention is as follows.

The general operation of the tester 1 of the present invention is as follows. That is, in the case of measuring DC current or AC current, rotate the rotary selector 4 so that the guideline (2) points to the measured value in the AC current measurement range table (11) or DC current measurement range table (12). Insert the jack into the ground probe of the common ground terminal socket (8). And the measurement probe is inserted into the current measuring socket (6) or a single unit current measuring socket (7) of 10 times the unit to measure the circuit to be measured by using two probes. When measuring battery voltage, resistance, or direct current or alternating voltage, refer to the instructions of the rotary selector (4) for the battery voltage measurement range table (13), resistance measurement range table (14), DC voltage measurement range table (15), or Point the measured value of the AC voltage measurement range table 16 and insert the jack of the measuring probe 5 into the voltage resistance measuring socket 9 to measure it.

With the user's carelessly plugging the jack (5) of the measuring probe into the current measuring socket (6) or (7), the instructions of the rotary selector (4) will be displayed in the battery voltage measurement range table (13) and the resistance measurement range table. (14) When the DC voltage measurement range table 15 or the AC voltage measurement range table 16 is indicated, when measuring the voltage of the circuit with the measurement probe, the tester magnetic circuit may be damaged. .

In this invention, such an inadvertent situation is prevented in advance.

That is, when the user inserts the jack 5 of the measuring probe into the current measuring socket 6 or 7, the sleeve 5b of the jack 5 is outside the socket body 6b, 7b. Inserted into the socket housing 6a, 7a, the upper outward curved portion 36 of the contact actuating piece 38A, 38B is moved to the contact piece 34, 35 side, so that the inwardly projecting portion 37 is moved to the contact piece. The 34 or 35 is deflected to the other side, and the contact pieces 34 and 35 can be contacted. Thus, the first detection switch 3 is closed.

In this state, the rotary selector 4 is rotated so that the guide (2) indicates the voltage and resistance measurement range, that is, the battery voltage measurement range table (13), the resistance measurement range table (14), and the DC voltage measurement range table (15). Alternatively, when the AC voltage measurement range table 16 is to be pointed, the movable contact 31b of the rotary selector 4 contacts the fixed contact 31a arranged within this range so that the second detection switch 31 is closed. do.

The comparator inverting input of the IC ₁ is applied to the lower input voltage than the reference setting voltage applied to the non-inverting input the output of the comparator IC ₁ becomes high. By the output of the comparator IC ₁ , the NAND gates G ₁ -G ₃ constituting the oscillation circuit operate and are amplified by the NAND gate G ₄ constituting the amplifying unit to ring the buzzer BZ, so that the jack 5 or the rotary selector of the measurement probe is measured. It warns that the position selection of (4) is wrong.

Claims (1)

A rotary selector (4) with a handle (3) marked with the instructions (2) is installed in the center of the tester (1) and has a 10-fold current measuring socket (6), a single-level current measuring socket (7), The common ground terminal socket 8 and the voltage resistance measuring socket 9 are disposed so that the jack 5 of the measuring probe, which comprises the pin 5a and the sleeve 5b around it, can be inserted. An electrical measuring circuit (17) is embedded inside, and as a warning circuit, a comparison discriminating unit (32) and a beep sound generating unit (33) are built in, and a movable ground contact between the two current measuring sockets (6) and (7). In the case where the 1st detection switch 30 which comprised the piece 34 and the movable contact piece 35 faced was mounted, the outer side of these contact pieces 34 and 35 is a contact operation piece for contacting or separating them ( 38A) and 38B are installed, and on the lower side of the rotary selector 4, a fixed contact 31a is arranged in an arc shape in a range corresponding to the voltage measurement range, and the rotary selector 4 is installed. In addition, the movable contact 31b constituting the second detection switch 31 together with the fixed contact 31a is installed, and the first detection switch 30 is connected to the second detection switch 31 to compare the discrimination unit 32. Alarm device for current, resistance and voltage testers connected to the system.