JP2000193691A - Plug socket checker - Google Patents

Abstract

PROBLEM TO BE SOLVED: To exactly carry out a discrimination of the voltage value of a plug socket. SOLUTION: Terminals L, N are connected to a power source voltage pole and a power source earth pole provided on the plug socket respectively. A comparator CP1 makes an output to H level, when a voltage between the terminals L, N is not less than 90 V, and a comparator CP2 makes an output to a H level when the voltage between the terminals L, N is not less than 113 V. A light emitting diode LED3 is connected between the output terminals of both comparators CP1, CP2 via a resistance and a light emitting diode LED4 is connected between the output end of the comparator CP2 and the cathode of a rectifier DB1 via a resistance. When, the voltage between the terminals L, N is 100 V, the output of the comparator CP1 goes to H-level, and the output of the comparator CP2 becomes L level to light on the light emitting diode LED3. When the voltage between the terminals L, N is 200 V, the outputs of both comparators CP1, CP2 become H-level and only the light emitting diode LED4 is lit.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an outlet checker for detecting the presence or absence of an abnormality in a wiring system by connecting to an outlet.

[0002]

2. Description of the Related Art There has been an outlet checker of this type having a function of checking the voltage and polarity of an outlet. This outlet checker has insertion blades respectively inserted into the outlets on the power supply voltage side and the power supply ground side of the outlet, and is applied between the power supply voltage side insertion blade and the power supply ground side insertion blade. When the applied voltage exceeds 100 V, 1
The light emitting element for 00V display is turned on, and the applied voltage is 2
When the voltage exceeds 00 V, the light emitting element for 200 V display is turned on, and the voltage is checked from the lighting state of the light emitting element for 100 V display and 200 V display.

[0003]

In the above-mentioned outlet checker, the applied voltage applied between the two insertion blades is 100V.
When the applied voltage exceeds 200 V, the light emitting element for displaying 100 V is turned on. When the applied voltage is 200 V or more, the light emitting element for displaying 200 V is turned on. Both light emitting elements for 200 V display were lit. Therefore, when the voltage of about 200 V or more is applied between the power supply voltage side and the power supply ground side insertion blades and the light emitting element for displaying 200 V is damaged and does not turn on, the light emitting element for displaying 200 V is used. Is turned off, but since the light emitting element for displaying 100 V is turned on, the voltage applied between both insertion blades is 200 V
Otherwise, the user may erroneously judge.

The present invention has been made in view of the above circumstances, and it is an object of the present invention to provide an outlet checker which can accurately determine the voltage value of an outlet.

[0005]

In order to achieve the above object, according to the first aspect of the present invention, there are provided two plugs which can be respectively inserted into a power supply voltage pole and a power supply grounding pole provided in an outlet. Blade, a first comparison circuit for comparing the level of an input voltage input from an outlet through these two insertion blades and a first reference voltage, and a second comparison circuit higher than the first reference voltage A second comparison circuit for comparing the level of the reference voltage with the input voltage, and an input voltage equal to or higher than the first reference voltage and a second reference voltage according to a combination of outputs of the first and second comparison circuits. A first light-emitting element that lights up when less than
And a second light-emitting element that is turned on when the input voltage becomes equal to or higher than the second reference voltage in accordance with only the output of the comparison circuit. When each is inserted into the ground pole, an input voltage is applied from the outlet between the two insertion blades, and if the input voltage is equal to or higher than the first reference voltage and lower than the second reference voltage, the first voltage is applied.
And turning on only the first light emitting element in accordance with the output of the second comparing circuit, turning off the first light emitting element when the input voltage becomes equal to or higher than the second reference voltage, and turning on only the output of the second comparing circuit. Accordingly, the second light-emitting element can be turned on. Here, when the first and second light emitting elements are both turned on when the input voltage becomes equal to or higher than the second reference voltage,
When the input voltage becomes equal to or higher than the second reference voltage when the second light emitting element is damaged and does not turn on, only the first light emitting element turns on. Therefore, the input voltage is changed from the lighting state of the first light emitting element. The user may erroneously determine that the voltage is lower than the second reference voltage. However, when the input voltage is equal to or higher than the first reference voltage and lower than the second reference voltage, the first light emitting element is used. Only the second light emitting element is turned on when the input voltage becomes equal to or higher than the second reference voltage. Therefore, if the second light emitting element is damaged and cannot be turned on, the input voltage becomes the second light emitting element. The light emitting element does not turn on even when the reference voltage is equal to or higher than the reference voltage, so that the user can be prevented from making an erroneous determination. Also, since only one of the first and second light emitting elements is turned on, when the input voltage is higher than the second reference voltage, compared to the case where both the first and second light emitting elements are turned on. Power consumption can be reduced.

According to a second aspect of the present invention, in the first aspect of the present invention, the first and second comparison circuits are provided with hysteresis generating means for providing hysteresis, respectively. Second
Is provided with hysteresis, it is possible to prevent the output from fluctuating due to the voltage fluctuation of the input voltage when the output of the first and second comparison circuits is inverted. It is possible to prevent the lighting state from flickering.

According to a third aspect of the present invention, in the first or second aspect of the present invention, the first and second comparison circuits are constituted by operational amplifiers. When one light emitting element is turned on, the other light emitting element is turned off, so that the power consumption of the light emitting element can be reduced as compared with the case where both light emitting elements are turned on.
In addition, since the comparison circuit is configured by an operational amplifier with low power consumption, power consumption can be further reduced.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS As shown in FIGS. 6 and 7, the outlet checker shown in this embodiment has an elongated rectangular parallelepiped body 1 that can be gripped by hand. Insertion blades 21, 22, 3 protrudable from one end face in the longitudinal direction
1 are provided. here,
The insertion blade 21 is provided so as to be able to be inserted into a power supply voltage pole insertion port 41 of the outlet 4, and the insertion blade 22 is provided so as to be able to be inserted into a power supply ground electrode insertion port 42 of the outlet 4. . That is, since both insertion blades 21 and 22 can correspond to a two-pole outlet, they are hereinafter referred to as a two-pole plug portion 2. Further, since the insertion blade 31 has a substantially U-shaped cross section and is provided so as to be able to be inserted into the insertion port 43 of the ground electrode of the outlet 4, it is hereinafter referred to as a grounding plug portion 3. As shown in FIG. 7, a jack 5 as a ground wire connecting portion is provided on the other end surface in the longitudinal direction of the body 1.
A terminal pin 52 connected to the other end of the ground wire 50 provided with the probe 51 at one end is removably inserted into the plug. The jack 5 is electrically connected to the insertion blade 31 inside the housing 1 and can be connected to a ground terminal 44 provided on the outlet 4 via a ground wire 50.

The circuit shown in FIG. Each terminal L, N, E in FIG. 1 is connected to the insertion blades 21, 22, 31 respectively. That is, the terminal L is connectable to the power supply voltage pole, the terminal N is connectable to the power supply ground pole, and the terminal E is connectable to the ground pole.
One ends of the fuses F1 and F2 are connected to the terminals L and N, respectively, and a surge absorber Z1 is connected between the other ends of the fuses F1 and F2. Further, a surge absorber Z2 is connected between the other end of the fuse F2 and the terminal E. Here, circled symbols a, b, c, d in FIG.
Means connected to each other. Although the fuses F1 and F2 have the function of protecting the circuit, they do not affect the electric circuit unless they are blown.
Description will be made ignoring 1, F2.

A diode D1 and a switch element Q composed of a pnp transistor are connected between the terminals L and N.
1, a series circuit of a diode D2 and two resistors R4 and R5 is connected, and three resistors R1 to R3 and two Zener diodes ZD1 and ZD are provided at the base of the switch element Q1.
The touch electrode 6 is connected via a series circuit with the touch electrode 2. The touch electrode 6 is exposed on the left side of the body 1 as shown in FIG. The touch electrode 6 is provided so that a part of the human body such as a fingertip can be contacted. When the touch electrode 6 is grounded through the human body, the voltage applied to the terminal L is defined by the Zener diodes ZD1 and ZD2. If the voltage exceeds the threshold voltage, the switching element Q1 conducts. The resistors R1 to R3 limit the current flowing through the human body to prevent electric shock. Here, a plurality of resistors R1 to R
3 is used, any one of the resistors R1 to R1
Even if R3 is short-circuited, the remaining resistor is inserted between the terminal L and the touch electrode 6 to prevent electric shock. A series circuit of a resistor R6, a light emitting diode LED1 as a polarity display unit, and a switch element Q2 composed of an npn-type transistor is also connected between the terminals L and N via a diode D1, and the base of the switch element Q2 is Resistance R4
It is connected to the connection point of R5.

In the above-described configuration, when the switching element Q1 conducts, the switching element Q2 conducts and the light emitting diode L
ED1 lights up. That is, when the power supply voltage electrode is connected to the terminal L while the touch electrode 6 is in contact with the human body, the potential difference between the terminal L and the touch electrode 6 exceeds the breakover voltage of the Zener diodes ZD1 and ZD2. Is set, and at this time, the switch element Q1 is turned on. As a result, the switch element Q2 is also turned on, and the light emitting diode LED1, which is the polarity display unit, is turned on. Conversely, if the light emitting diode LED1 is turned on, it can be confirmed that the terminal L is connected to the power supply voltage pole of the outlet 4.

A diode D is connected between terminals L and E.
1, a series circuit of three resistors R7, R8, and R9 as impedance elements for detection is also connected. Resistance R
8, R9 is connected to a diode D3 and two resistors R1.
0 and R11 are connected to the terminal N via a series circuit, and a Zener diode ZD3 is connected in parallel to the resistor R11. Further, a connection point between the two resistors R10 and R11 is connected to a base of a switch element Q3 formed of an npn-type transistor. The Zener diode ZD3 provides a reference voltage, and when the voltage across the resistor R11 reaches the breakover voltage of the Zener diode ZD3, the switch element Q3 turns on. That is, a voltage detection circuit is formed by the switch element Q3 and the Zener diode ZD3. A series circuit of a resistor R12 and a capacitor C1 and a resistor R14 are connected to the collector and the emitter of the switch element Q3.
Are connected in parallel. Also, the resistor R1 has a resistor R1.
3 are connected in series, and a series circuit of resistors R13 and R14 is connected between terminals L and N via a diode D1. A series circuit of a resistor R15, a light emitting diode LED2 as a ground indicator, and a switch element Q4 composed of an npn-type transistor is connected in parallel to the series circuit of the resistors R13 and R14, and a connection point between the resistors R13 and R14 and the switch element Q4.
A resistor R16 is inserted between the base and the base.

Here, resistors R7, R8, R10, R11
Is set such that the voltage across the resistor R11 reaches the breakover voltage of the Zener diode ZD3 when the terminal E is not grounded, and in this state, the switching element Q3 conducts. When the switching element Q3 is turned on,
Since the capacitor C1 is discharged, the switching element Q4 becomes non-conductive, and as a result, the light emitting diode LED2 is turned off. On the other hand, since a series circuit of resistors R7, R8 and R9 is inserted between the terminals L and E, when the impedance between the terminal E and the ground becomes small, the voltage across the resistor R11 becomes the breakover voltage of the Zener diode ZD3. Lower than. The impedance when the voltage across the resistor R11 is lower than the breakover voltage of the Zener diode ZD3 is set to 500Ω. This value is a value specified as a third-class grounding resistance in the case of using an earth leakage breaker according to the technical standards for electrical equipment and the extension. Thus, when the terminal E is grounded, the switch element Q3 is turned off and the capacitor C1 is charged through the resistor R12. Therefore, when the time determined by the capacitor C1, the resistors R12, R13 and the like has elapsed, the switch element Q4 is turned off. Turn on. In short, the collector voltage of the switching element Q3 is, as shown in FIG.
If it is less than or equal to H level, the impedance is 5
When it becomes 00Ω or more, it becomes L level. As a result, when the impedance is 500Ω or less, the light emitting diode LED2 is turned on. In this way, when the light emitting diode LED2 is turned on, it is possible to know that the terminal E is grounded, and it is possible to connect the terminal E to a ground electrode corresponding to the outlet 43 of the outlet 4 or to connect the outlet E to the ground. When the ground terminal or the ground terminal 44 is securely grounded, the light emitting diode LED2 is turned on, and it can be confirmed that the wiring system is correctly connected.

A series circuit of resistors R17 and R18 is connected between the terminals L and N via a rectifier DB1 composed of a diode bridge.
The voltage is divided by R18. Further, the voltage between both ends of the resistor R18 is smoothed by the capacitor C2 and applied to the non-inverting input terminals of two comparators CP1 and CP2 as first and second comparison circuits using an operational amplifier via the resistor R21. The voltage between both ends of the series circuit of the resistors R17 and R18 is passed through the parallel circuit of the resistors R19 and R20 to the capacitor C.
3, the voltage between both ends of the capacitor C3 is made constant by a series circuit of the Zener diode ZD4 and the diode D4, and the three resistors R22 and R2
The voltage is divided by a series circuit of R3 and R24, and a reference voltage is applied to the inverting input terminals of the comparators CP1 and CP2.
Resistors R25 and R26 as hysteresis generating means are connected between the output terminals of the comparators CP1 and CP2 and the non-inverting input terminals, respectively.
Hysteresis is given to the comparators CP1 and CP2 by applying a positive feedback from the output by 26. That is, the output of the comparators CP1 and CP2 is H
Compared to the input voltage when rising to level (high)
By lowering the input voltage at the time of falling to the level (low), the outputs of the comparators CP1 and CP2 do not fluctuate even when the input voltage fluctuates at the time of rising or falling of the output.
It is possible to prevent the lighting state of the ED 4 from flickering. The comparators CP1 and CP2 are provided to identify whether the effective value of the voltage applied between the terminals L and N is 100 V or 200 V. For example, the comparator CP1 has the terminals L and N
Output is H when the voltage between them is about 90 V (first reference voltage) or more.
Level, and the output of the comparator CP2 goes high when the voltage between the terminals L and N is about 113 V (second reference voltage) or more. A resistor R27 and a light emitting diode L as a first light emitting element are provided between the output terminals of the comparators CP1 and CP2.
A series circuit with ED3 is connected, and a series circuit with a resistor R28 and a light emitting diode LED4 as a second light emitting element is connected between the output terminal of the comparator CP2 and the negative electrode of the rectifier DB1.

Therefore, when the voltage between the terminals L and N is 100
If V, the output of comparator CP1 is at H level and the output of comparator CP2 is at L level.
When only the light emitting diode LED3 is turned on and the voltage between the terminals L and N is 200 V as shown in FIG.
Since the outputs of P1 and CP2 are both at the H level, only the light emitting diode LED4 is turned on. As described above, the light emitting diode LED3 is turned on when the voltage between the terminals L and N becomes equal to or more than the first reference voltage and less than the second reference voltage according to the combination of the outputs of the comparators CP1 and CP2. Lights up when the voltage between the terminals L and N is equal to or higher than the second reference voltage in accordance with only the output of CP2, and the two light emitting diodes LED3 and LED4 are alternatively selected in accordance with the voltage applied to the terminals L and N. , The power consumption is smaller than when both are lit at the same time. Further, since the first and second comparison circuits are composed of operational amplifiers with low power consumption, power consumption can be further reduced. Assuming that terminals L and N
If a configuration is adopted in which one light emitting diode is turned on when the voltage between them is 100 V and two light emitting diodes are turned on when the voltage is 200 V, the light emitting diode that is turned off when the voltage is 100 V is damaged and lights up. When it disappears, 100V despite 200V being applied
However, by adopting the above configuration, the two light emitting diodes LED3 and LED4 emit light alternatively according to the voltage between the terminals L and N. Therefore, this kind of erroneous recognition does not occur. It is. Further, since the comparators CP1 and CP2 are provided with hysteresis by the resistors R25 and R26, when the output goes to the H level, the state is maintained, and the light emitting diode LE due to the voltage fluctuation.
D3 and LED4 are prevented from flickering.

As described above, by using the present apparatus, the polarity of the outlets 41 and 42 of the outlet 4, the grounding state of the outlet 43 or the ground terminal 44, and the distance between the power supply voltage pole and the power supply grounding pole can be obtained. The voltage is respectively the light emitting diode LE
It can be identified by the lighting state of D1, LED2, LED3, and LED4.

Incidentally, a pseudo earth leakage circuit for generating an earth leakage in a pseudo manner is added to this apparatus. The pseudo earth leakage circuit includes a rectifier DB2 composed of a diode bridge connected between terminals L and E. A thyristor SCR as a switch element and a diode D5 are provided between output terminals of the rectifier DB2 via a resistor R29 as an impedance element. Are connected in series. A surge absorber Z3 is connected between the input terminals of the rectifier DB2, and a thyristor SCR
A snubber circuit composed of a series circuit of a resistor R30 and a capacitor C4 is connected in parallel to a series circuit of the diode D5 and the diode D5. The thyristor SCR is controlled via a one-shot circuit so that when a switch SW having a mechanical contact is turned on, it is turned on for a specified conduction time.

The pseudo earth leakage circuit includes a rectifier DB3 comprising a diode bridge connected between terminals L and N;
The control power supply includes a resistor R34 for smoothing the output of the rectifier DB3, a capacitor C7, and a Zener diode ZD5 for making the voltage across the capacitor C7 constant. The output of the control power supply is connected to a one-shot circuit via a switch SW. One shot circuit is pnp
A switching element Q5 formed of a transistor of a thyristor type is provided, and the gate of the thyristor SCR is connected to the collector of the switching element Q5 via a resistor R31. Thyristor S
A capacitor C5 is connected between the gate of CR and the cathode of the diode D5.
Thus, the noise of the gate signal to the thyristor SCR is removed. Further, a switch S is provided between the output terminals of the control power supply.
A resistor R35 is connected via W and a resistor R3
5, a series circuit of a resistor R33 and a capacitor C6 is connected in parallel. The base of the switch element Q5 is connected to a connection point between the resistor R33 and the capacitor C6, and is made conductive when the terminal voltage of the capacitor C6 is reduced.

Therefore, when the switch SW is turned on as shown in FIG. 4A, the voltage across the resistor R35 rises as shown in FIG. 4B, and the resistor R33 as shown in FIG.
, The capacitor C6 is charged, and the voltage across the capacitor C6 rises with time. Here, since the switching element Q5 is conducting, the output of the control power supply passes through the switch SW and the switching element Q5 as shown in FIG.
Is applied to the gate of the thyristor SCR to turn on the thyristor SCR. Thereafter, as the capacitor C6 is charged, as shown in FIG.
When the base-emitter voltage decreases to Vf to the extent that the conduction state of the switching element Q5 cannot be maintained because the emitter voltage decreases, the above-described conduction time ends, the switching element Q5 turns off, and at the zero crossing point of the commercial power supply, The thyristor SCR turns off. That is, the thyristor SCR is turned on at the same time as the switch SW is turned on, and the resistance R3
3, the thyristor SCR is turned off after the conduction time defined by R35 and the capacitor C6 has elapsed. When the switch SW is turned off, the capacitor C6 is discharged through the resistors R33 and R35. Therefore, when the switch SW is turned on when the voltage across the capacitor C6 drops to such an extent that the switch element Q5 can be turned on, the thyristor The SCR can be turned on again.
However, the conduction time in this case changes according to the amount of electric charge remaining in the capacitor C6, and the time interval between the time when the switch SW is turned off and the time when the switch SW is turned on next is determined by the time required for the capacitor C6.
When the residual charge of No. 6 is shorter than the rest time, which is the time until the residual charge becomes substantially zero, the conduction time also becomes shorter.

That is, as shown in the left half of FIG. 5, even if the switch SW is kept turned on (see FIG. 5A), the time during which the thyristor SCR is turned on as shown in FIG. Becomes the conduction time t1. On the other hand, as shown in the right half of FIG. 5, when the switch SW is turned on / off in a relatively short time (see FIG. 5A), the terminal voltage of the capacitor C6 is not sufficiently reduced.
6 rises in a short time, turning off the switching element Q5. As a result, as shown in FIG.
The conduction time tx at which the CR turns on is shortened. With such an operation, it is possible to prevent the internal circuit from being overheated due to the current flowing between the terminals L and E when a pseudo leakage state occurs.

As described above, the terminals L and N corresponding to the power supply voltage pole and the power supply ground pole are connected to the internal circuit via the fuses F1 and F2, and the terminal E is not provided with a fuse. Therefore, since the internal circuits are connected to the terminals L and N corresponding to the power supply voltage pole and the power supply ground pole via the fuses F1 and F2, for example, the terminals L and N, the terminals L and E, and the terminal N , E between 2
Even if an overcurrent flows when 00 V is applied and the insertion blades 21 and 22 are inserted into the insertion ports 41 and 42 of the outlet 4, the internal circuits are protected by the fusing of the fuses F1 and F2. Further, if any one of the fuses F1 and F2 is blown, the touch electrode 6 is turned on regardless of the polarity of the insertion blades 21 and 22 with respect to the insertion ports 41 and 42 of the outlet 4.
Light-emitting diode LED1 as polarity indicator even if touched
Does not light up, this causes fuses F1, F
2 can be known. Here, if a fuse is also provided at the terminal E, there is no means for detecting that the fuse has blown, so that it is not possible to know whether there is an erroneous wiring on the outlet 4 side or a failure of the outlet checker. Further, even if the switch SW is turned on, it is not possible to simulate an electric leakage and the electric leakage breaker does not operate. Therefore, in this case, it is impossible to know whether the electric leakage breaker is faulty or the outlet checker is faulty. Therefore, by not providing a fuse at the terminal E, this kind of problem is avoided.

By the way, the above-mentioned circuit portion is divided and mounted on two large and small circuit boards 61 and 62 each composed of a printed wiring board housed in the body 1, as shown in FIG. Each light emitting diode LED1, LED2, LED3, LED4
Is mounted on the larger circuit board 61, and the pseudo leakage circuit is mounted on the smaller circuit board 62. However, the switch SW is attached to the circuit board 61 and the connection line 63
Is connected to the pseudo-leakage circuit via

The body 1 is formed by combining a body 11 and a case 12 which are divided into two parts in the thickness direction. A cutout window 13 is formed on one side in the width direction, and is exposed on the other side. A window 14 is formed. Vessel 1 from notch window 13
The operation protrusion 15a of the slide handle 15 movable in the longitudinal direction is exposed.

The slide handle 15 has a rectangular plate shape as shown in FIG. 9, and is provided between the guide rib 1a formed inside the body 1 and substantially parallel to the peripheral wall of the body 1 and the peripheral wall of the body 1. The peripheral portion is held, and is movable in the longitudinal direction of the body 1. Further, the slide handle 15 is provided with a push piece 15b protruding inside the housing 1, and when the slide handle 15 is slid, the switch SW is pressed by the push piece 15b. That is, the switch S
A momentary push button switch (that is, a switch that is turned on only during a push operation) is used for W, and the push piece 15b of the slide handle 15 is provided at a position where the push button 15c of the switch SW can be pushed. Slide handle 1
A spring receiving piece 15d protrudes from a part of 5, and the spring receiving piece 15d functions as a spring seat for receiving one end of a return spring 16 formed of a coil spring. A spring holding rib 11a is formed on the inner surface of the bottom wall of the body 11 so as to house the return spring 16, and the return spring 16 is held between the spring holding rib 11a and the spring receiving piece 15d. Will be. The return spring 16 is a pressing piece 1 of the slide handle 15.
The switch 5b is urged in a direction in which the switch 5b is pulled away from the push button 15c of the switch SW, and when no operation force is applied to the slide handle 15, the switch SW is kept off.

On the other hand, the touch electrode 6 formed of a conductive plate (usually a metal plate) is exposed through the exposure window 14. The touch electrode 6 is fixed to the body 1 by its peripheral portion being held in a holding groove 1 b formed in the peripheral wall of the body 1. Further, a jack 5 is provided at one end of the body 1 in the longitudinal direction.
Is attached. By providing the touch electrode 6 on the opposite side of the slide handle 15, the operation of the slide handle 15 and the touch of the touch electrode 6 can be performed with one hand, and the operability is good. In particular, since the slide handle 15 is located on the right side, it can be operated with the thumb when the person is right-handed, and the operation is also easy in this respect.

On the other hand, a two-pole plug portion 2 and a grounding plug portion 3 are provided at the other end (front end when held by hand) of the body 1 in the longitudinal direction. The two-pole plug portion 2 includes a pair of support plates 23 mounted on the circuit board 61 and arranged in parallel.
And the insertion blades 21,
22 is rotatably mounted on the shaft. Here, the insertion blades 21 and
Reference numerals 2 correspond to the terminals L and N in the above-described circuit unit, respectively. A cutout groove 61a having an open front end is formed at a portion corresponding to the two-pole plug portion 2 on the circuit board 61, and two fixing projections 61b are formed at the front end of the inner edge of the cutout groove 61a. It is protruding. Each of the support plates 23 includes an L-shaped connection piece 23a protruding in a direction away from each other, and includes a fixing hole 23b fitted into the fixing projection 61b, and the connection piece 23 from the lower side of the circuit board 61 in FIG.
a into the circuit board 61 and the fixing projection 61b.
The fixing hole 23b is fitted to the
1 is mounted in a form fixed firmly.

A movable body 24 made of an insulating material such as a synthetic resin is sandwiched between the two support plates 23, and a part of each of the insertion blades 21 and 22 is inserted into mounting grooves 24a provided on both side surfaces of the movable body 24. The insertion blades 21 and 22 and the movable body 24 are integrally rotatable by fitting. That is, both insertion blades 2
Reference numerals 1 and 22 are rotatable with respect to the support plate 23 while maintaining the positional relationship with respect to the movable body 24. Cover 12
A storage groove 12a for storing the movable body 24 is formed at the front end in FIG. 8, and a cover 1 is provided behind the storage groove 12a.
2, an open storage recess 12b is formed in the upper surface. A partition 12 is provided between the storage groove 12a and the storage recess 12b.
c is formed, and the insertion blades 21 and
An insertion groove 12d into which the second 2 can be inserted is formed.

The insertion blades 21 and 22 are shown in FIG.
FIG. 10 shows a position protruding from the front surface of the body 1 as shown in FIG.
As shown in (b), it is rotatable between a position where it is stored in the storage recess 12b and retracts from the front surface. Insertion blades 21, 22
Is stored in the storage recess 12b, each of the insertion blades 2
1 and 22 are inserted into the insertion grooves 12d.
The partition wall 12c is interposed between the insertion blades 21 and 22, so that even if an external force acts in a direction to approach the insertion blades 21 and 22, the insertion blades 21 and 22 abut the partition wall 12c and the insertion blades 21 and 22 are inserted. Is prevented from being deformed. Furthermore, the left and right width of the storage recess 12b is formed larger than the interval between the insertion blades 21 and 22,
As shown in FIG. 11, the insertion blades 21 and 22 can be pinched and rotated by a fingertip. At this time, an external force acts in a direction in which the insertion blades 21 and 22 are brought closer to each other, but the presence of the partition wall 12c prevents the insertion blades 21 and 22 from being deformed.

On the other hand, the grounding plug 3 is connected to the circuit board 61.
The receiving spring 32 is mounted so as to straddle a pair of connecting projections 61c provided behind the fixing projection 61b in the notch groove 61a formed in the groove. Here, the receiving spring 32 corresponds to the terminal E in the circuit section described above. Receiving spring 3
8 has a connection piece 32a projecting left and right at the rear end, and a U-shaped blade receiving part 32b opened downward in FIG. 8 at the front end.
Having. The insertion blade 31 is attached to the body 11 by a shaft pin 33.
12 and 13, and is stored in a storage recess 11c provided in the lower surface of the body 11 at a position protruding forward of the body 1 through a cut groove 11b provided in the lower surface of the body 11 as shown in FIGS. (FIG. 14 shows an intermediate state between the two positions). That is, the insertion blade 31 is rotatable between a position protruding from the front surface of the housing 1 and a position retracting from the front surface of the housing 1. As shown in FIG. 15, the blade receiving portion 32b of the receiving spring 32
Is exposed in the incision 11b, and at a position where the insertion blade 31 projects from the front surface of the body 1, the insertion blade 31 is
The receiving spring 32 and the insertion blade 31
Are electrically connected. Conversely, since the insertion blade 31 is not connected to the receiving spring 32 until the insertion blade 31 protrudes from the front surface of the body 1, the switch SW is turned on while the insertion blade 31 is stored in the storage recess 11c. Sometimes insert blade 31
No electric shock even if your finger touches Insert blade 31
Is also formed in such a width that a fingertip can be inserted and the insertion blade 31 can be pulled out.
The lower surface of the storage groove 12a provided in the cover 12 is covered by the insulating plate 17, and the receiving plate 32 and the support plate 2 are covered by the insulating plate 17.
3 is maintained.

As described above, the two-pole plug portion 2 having the insertion blades 21 and 22 and the grounding plug portion 3 having the insertion blade 31 are different from the storage recesses provided on the front and back surfaces of the body 1. Place 12
b, 11c, it is possible to separately put in and out of the body 1. For example, when the outlet 4 is provided with only two insertion ports 41, 42, the two-pole plug 2 When only the insertion blades 21 and 22 can be used by protruding from the body 1 and the outlet 4 is provided with the insertion port 43 serving as a ground electrode and has three insertion ports 41, 42 and 43, The grounding plug 3 can also be used by projecting from the body 1. Further, when the outlet 4 is provided with a ground terminal 44, the outlet 4 can be connected to the ground terminal 44 using the ground wire 50.
In short, various types of outlets 4 can be supported. In addition, since the insertion blades 41, 42, 43 do not protrude from the body 1 when not in use, packing and carrying are easy, and the appearance is good.

The outlet 4 provided in the outlet 4
In the case where the longitudinal dimensions of the power supply terminals 1 and 42 are made different from each other, the power supply ground electrode is generally made larger than the power supply voltage electrode.
Therefore, the width of the insertion blade 22 is set to be larger than the width of the insertion blade 21.
When the insertion blades 21 and 22 are inserted into the insertion ports 41 and 42, they can be prevented from being connected with opposite polarities.

In the above example, whether or not the terminal E is grounded is determined based on the voltage divided by the resistors R7, R8 and R9. However, as shown in FIG. A constant current is supplied from the current source Is to the resistor R0 connected to the LED, and the voltage detection circuit DV detects a change in the terminal voltage of the resistor R0 when the terminal E is grounded, thereby lighting the light emitting diode LED2. It is good also as a structure to make it.

[0033]

As described above, according to the first aspect of the present invention, there are provided two insertion blades each of which can be inserted into a power supply voltage pole and a power supply grounding pole provided in an outlet, and these two blades. A first comparison circuit for comparing the level of an input voltage input from an outlet via the insertion blade with a first reference voltage;
A second comparison circuit that compares the level of the input voltage with a second reference voltage higher than the reference voltage of the first and second reference voltages; A first light-emitting element that lights when the voltage is equal to or higher than the voltage and is lower than the second reference voltage, and a second light-emitting element that lights when the input voltage is equal to or higher than the second reference voltage in accordance with only the output of the second comparison circuit. When the two insertion blades are inserted into the power supply voltage pole and the power supply ground pole of the outlet, respectively, the input voltage is applied from the outlet between the two insertion blades, and the input voltage is set to the first reference voltage. When the voltage is equal to or higher than the voltage and lower than the second reference voltage, only the first light emitting element is turned on according to the outputs of the first and second comparison circuits, and the input voltage is set to the second voltage.
, The first light-emitting element can be turned off, and the second light-emitting element can be turned on only in accordance with the output of the second comparison circuit. Here, when both the first and second light emitting elements are turned on when the input voltage becomes equal to or higher than the second reference voltage, when the second light emitting element is damaged and no longer emits light, the input voltage becomes lower. When the voltage is equal to or higher than the second reference voltage, only the first light emitting element is turned on. Therefore, the user may erroneously determine that the input voltage is lower than the second reference voltage from the lighting state of the first light emitting element. However, as described above, when the input voltage is equal to or higher than the first reference voltage and lower than the second reference voltage, only the first light emitting element is turned on, and when the input voltage is equal to or higher than the second reference voltage, the second light emitting element is turned on. Since only the light-emitting element is turned on, if the second light-emitting element is damaged and does not turn on, the light-emitting element does not turn on even if the input voltage becomes higher than the second reference voltage. There is an effect that misjudgment can be prevented. Also, since only one of the first and second light emitting elements is turned on, when the input voltage is higher than the second reference voltage, compared to the case where both the first and second light emitting elements are turned on. Power consumption can be reduced.

According to a second aspect of the present invention, in the first aspect of the present invention, the first and second comparison circuits are provided with hysteresis generating means for providing hysteresis, respectively. Since the second comparison circuit is provided with hysteresis, it is possible to prevent the output from fluctuating due to the voltage fluctuation of the input voltage when the outputs of the first and second comparison circuits are inverted, and the first and second light emission. There is an effect that the lighting state of the element can be prevented from flickering.

According to a third aspect of the present invention, in the first or second aspect of the present invention, the first and second comparison circuits are composed of operational amplifiers. When one light emitting element is turned on, the other light emitting element is turned off, so that the power consumption of the light emitting element can be reduced as compared with the case where both light emitting elements are turned on, and the comparison circuit is consumed. Since the operational amplifier is configured with low power, there is an effect that power consumption can be further reduced.

[Brief description of the drawings]

FIG. 1 is a circuit diagram of an outlet checker according to an embodiment.

FIG. 2 is an explanatory diagram of an operation of the outlet checker according to the first embodiment;

FIGS. 3A to 3C are explanatory diagrams of the operation of the outlet checker according to the first embodiment;

FIGS. 4A to 4E are explanatory diagrams of the operation of the outlet checker according to the first embodiment;

FIGS. 5A and 5B are explanatory diagrams illustrating the operation of the outlet checker according to the first embodiment;

FIG. 6 is an external perspective view of the outlet checker as viewed from the front.

FIG. 7 is an external perspective view of the outlet checker as viewed from the rear.

FIG. 8 is an exploded perspective view of the outlet checker.

FIG. 9 is an exploded perspective view of a main part of the outlet checker.

10A and 10B show the outlet checker of the above, wherein FIG. 10A is a perspective view showing a state where the insertion blade is protruded, and FIG. 10B is a perspective view showing a state where the insertion blade is retracted.

FIG. 11 is a perspective view of the upper surface side of the outlet checker.

FIG. 12 is a perspective view of the lower surface side of the outlet checker.

FIG. 13 is a sectional view of a main part of the outlet checker.

FIG. 14 is a cross-sectional view of a main part of the outlet checker.

FIG. 15 is a front view of a main part of the outlet checker.

FIG. 16 is a main part circuit diagram showing another configuration example of the outlet checker of the above.

[Explanation of symbols]

 L, N terminal CP1, CP2 Comparator LED3, LED4 Light emitting diode

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Hitoshi Nishiwaki 737-12, Anata-cho, Seto-shi, Aichi Fari-term in Owari Matsushita Electric Works Co., Ltd. 2G033 AD21 AG12 2G035 AA20 AA24 AB08 AC13 AC16 AC18 AD02 AD04 AD08 AD09 AD10 AD11 AD13 AD14 AD16 AD23 AD40 AD45 AD47 AD56

Claims (3)

[Claims] 1. Two insertion blades respectively insertable into a power supply voltage pole and a power supply grounding electrode provided in an outlet, and an input input from the outlet via the two insertion blades. A first comparison circuit for comparing the level of a voltage with a first reference voltage, a second comparison circuit for comparing the level of a second reference voltage higher than the first reference voltage and the input voltage, ,
Only the first light-emitting element that is turned on when the input voltage becomes equal to or higher than the first reference voltage and lower than the second reference voltage according to the combination of the outputs of the first and second comparison circuits, and only the output of the second comparison circuit And a second light-emitting element that lights up when the input voltage becomes equal to or higher than a second reference voltage in accordance with the power supply. 2. The outlet checker according to claim 1, further comprising hysteresis generating means for providing hysteresis to said first and second comparison circuits. 3. The outlet checker according to claim 1, wherein said first and second comparison circuits comprise an operational amplifier.