JPH0712933Y2 - Electronic voltage detector - Google Patents

Description

[Detailed description of the device]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electronic voltage detector for testing the charging of electric circuits.

[0002]

2. Description of the Related Art FIG. 7 is a cross-sectional view of a conventional electronic voltage detector, 1 is an outer case of the voltage detector, 2 is a sensing electrode having a built-in capacitor, 3 is a judgment circuit board portion, and 4 is a display circuit. Substrate part, 5 is a piezoelectric buzzer, 6 is a large number of small holes for the piezoelectric buzzer 5, 7 is an LED, 8 is a transparent window for emitting light of the LED, 9 is a switch for self-circuit test, 10 is a battery, 11 is a power switch. is there.

FIG. 8 is a block diagram of a conventional electronic voltage detector, in which 12 is an external electric circuit for applying electric power, 13 is a self-test circuit, 14 is a level detection circuit, and 15 is a display circuit.

Next, the operation will be described. When the power switch 11 is pressed to turn it on, and the self-circuit test switch 9 is pressed to operate the self-test circuit and a test voltage is applied to the internal self-circuit, the level detection circuit 14, the display circuit 15, and the battery 10 are normal. For example, the LED 7 lights up, the buzzer 5 sounds, the test is completed, and the test switch 9 is turned off.

Next, when the detection electrode 2 having a built-in capacitor is brought into contact with the circuit 12 to be detected to detect the applied voltage, a detection voltage is output from the level detection circuit 14 and is amplified by the display circuit 15 to turn on the LED 7 and the buzzer 5 Sounds and the charging is detected. Finally, the power switch 11 is turned off to complete the power detection.

[0006] In addition, some conventional electronic voltage detectors are provided with another LED for indicating the capacity of the battery, or the power switch 11 is omitted and the circuit is powered on in advance and tested quickly. For example, press the switch to start the test display.

[0007]

Since the conventional electronic voltage detector is constructed as described above, both the power switch and the self-circuit test switch are required, and a separate self-test circuit for testing is provided. Must be tested. In addition, there is a problem that a separate LED must be used for displaying the capacity of the battery, or if the power switch is omitted and the power is turned on in advance, the battery will be consumed quickly.

The present invention has been made to solve the above-mentioned problems. In testing a self-circuit, a self-test circuit and a switch for self-circuit test are not required, and battery capacity confirmation and self-circuit test display are possible. An object of the present invention is to provide an electronic voltage detector that can prevent the wasteful consumption of the battery, and can confirm the detection display of the applied electricity by displaying it separately with one LED.

[0009]

SUMMARY OF THE INVENTION An electronic voltage detector according to the present invention comprises a level determination circuit for detecting a detected voltage application,
Bias voltage generation circuit that outputs a threshold voltage as the bias voltage of the level determination circuit and doubles as an electronic switch for self-circuit test of the device, and the above-mentioned charging display and battery capacity and self-circuit test display blinking and lighting the LED. And a display circuit for displaying and distinguishing by continuous lighting.

[0010]

In the electronic detector of the present invention, the bias voltage generating circuit outputs the threshold voltage as the bias voltage of the level judging circuit and also serves as the electronic switch for the self-circuit test. By turning on the light, it is possible to display the indication of the charging and the battery capacity and the self-circuit test.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a sectional view of the electronic voltage detector of the present invention,
The reference numerals are the same as the conventional example except that the self-circuit test switch 9 is omitted and the battery 10 is downsized.

FIG. 2 is a block diagram of the electronic voltage detector of the present invention, in which 20 is a bias generation circuit and electronic switch, 21 is a level determination circuit, 22 is an LED display circuit, 23 is a piezoelectric buzzer drive circuit, and others. The sign of is the same as that of the conventional example.

FIG. 3 is a concrete circuit diagram of the bias generating circuit 20 and the level judging circuit 21 of the present invention, and IC ₁ is a logic IC or IC ₂ which generates a threshold voltage by negative feedback constituting the bias generating circuit 20. Is a logic IC provided on the same chip as IC ₁ , which constitutes the level judgment circuit 21 by judging the input level by the threshold value.
R ₁ and R ₂ are bias voltage dividing resistors, and R and R ₃ are addition resistors.

Next, the operation will be described. When supplying the power supply voltage V _DD to the circuit by pressing the power switch 11, IC ₂ IC ₁ 'and the level judging circuit 21 in the bias generation circuit 20
Is a logic IC which is provided on the same chip and has a uniform threshold value characteristic. Therefore, when the level judgment circuit is normally constructed by the combination of IC ₁ and IC ₂ ,
The threshold voltage for judging whether the logic of IC ₂ is “1” or “0” is set as the level judgment voltage of the input signal, and the input signal is I
When the threshold voltage value of C ₂ is exceeded, IC ₂ is inverted and output.

Further, in this case, in order to accurately set the judgment level, the threshold voltage of IC ₂ and the bias voltage V at point A
_{Since O} must always hold a certain constant potential difference correctly, the threshold voltage of IC ₁ which is provided as a bias generation circuit on the same chip as IC ₂ and has the same threshold characteristics is used as the bias voltage of IC ₂ . Designed for use as a voltage. The threshold output voltage of IC _{1 is} the voltage dividing resistor R ₁
Are divided by R ₂ and R ₂ to generate a specified bias voltage at point A, and the bias voltage V _O and the input signal voltage V _A are R and R ₃
When the input voltage added in step ₂ exceeds the threshold voltage of IC ₂ , IC ₂ outputs inverted.

In the case of the present invention, a combination of logic ICs IC ₁ and IC ₂ on the same chip is used, and the bias voltage value at the point A is set to IC ₂ by reversing the setting conditions in the case of the normal basic operation. The set value set higher than the threshold voltage value of is set to the minimum voltage value at which IC ₂ inverts.

Therefore, when the power switch 11 is turned on, the IC ₂ is inverted even when the input signal V _A is zero, and the level determination circuit 2
1, the display circuit 22 is driven, and the LED 7 is continuously lit. This confirms the capacity of the internal battery 10,
The tests of the self circuits 21 and 22 are completed at the same time. In this way, the bias circuit 20 functions as a test electronic switch of its own circuit in addition to the function of supplying the bias of the level determination circuit.

When the test of the self-circuit is completed, the detection electrode 2 is then brought into contact with the test circuit 12 to detect the applied voltage, and the input of the IC _{2 at} the point B is the bias V _O set previously. Since it fluctuates up and down in response to the input waveform around the center, the output waveform of IC ₂ becomes a pulse waveform that repeats opening and closing. For example, when a commercial 50-cycle voltage application is detected, a positive half-wave is a positive pulse The wave will behave like a negative pulse, and
, The display circuit 22 receives the LE signal by this pulse.
Since the D7 is driven, the LED 7 can display blinking lighting to detect the electric power supply to the electric circuit. In addition, LED continues
When 7 is continuously lit, it is determined that no electricity is applied.

In the case of this invention, the display device is also shown as a combination of piezoelectric buzzer, but when it is not necessary, it is a light emitting type electronic voltage detector with 1 LED 71 for charging display, battery capacity, self-circuit test. Is sufficient, and since it is double, the buzzer 5 may be omitted. When the test is completed, the power switch 11 is turned off at last to prevent wasteful consumption of the battery.

Next, another embodiment of the present invention will be described. FIG. 4 is a perspective view of an electronic voltage detector according to another embodiment of the present invention, in which 30 is an outer case shaped to fit in a pocket of a notebook-shaped mold, and 33 is an outer case 30.
It is the power switch pushing part of the grip part.

FIG. 5 is a side view of an electronic voltage detector according to another embodiment of the present invention, in which 31 is a circuit board portion and 32 is a grip portion 3.
A seal 3 and a power switch 34.

FIG. 6 is an explanatory view for detecting electric circuit charging of an electronic detector of another embodiment of the present invention, and other reference numerals are the same as those of the above-mentioned embodiment.

Next, the operation will be described. There are two types of conventional electronic voltage detectors, one with a power switch and the other without.There is a problem with the type with a power switch, such as detecting electricity without turning on the switch or forgetting to turn off the switch to accelerate battery consumption. Also, in the case of the type without a switch, the current is always kept flowing, so a large current does not flow unless the display drive circuit operates due to the input voltage applied, but it is a wasteful consumption, and it is small when the device is downsized. There was a problem that the battery could not be used.

Therefore, in this invention, since the position of the electroscope to be grasped is determined in order to have a certain electrostatic capacity between the electroscope and the human body, when the electric grip is pushed into this grip,
The push switch 33 is provided so that it can be cut off when released. The power switch 34 is turned on at the same time when the electroscope is gripped, and turned off when released. As a result, useless consumption of the battery 10 can be prevented and the capacity of the battery 10 can be reduced, which facilitates downsizing of the device.

Since the basic operation of the internal circuit configuration is exactly the same as that of the above embodiment, the self-circuit test switch 9 is used.
There is no need for it, and the design on the external case can be made into a neat shape, which makes it convenient to carry and allows you to perform voltage detection work in the shape shown in FIG.

[0026]

As described above, according to the present invention, the bias generation circuit is used as both the bias generation of the level determination circuit and the electronic switch for self-circuit test, and the display is constituted by one LED, so that the device is not wasted. It is possible to omit the functions and realize the functions, and it is possible to reduce the size and cost of the device.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of an electronic voltage detector which is an embodiment of the present invention.

FIG. 2 is a block diagram of an electronic voltage detector which is an embodiment of the present invention.

FIG. 3 is a specific circuit diagram of a bias generation circuit and a level determination circuit of the present invention.

FIG. 4 is a perspective view of an electronic voltage detector according to another embodiment of the present invention.

FIG. 5 is a side view of an electronic voltage detector according to another embodiment of the present invention.

FIG. 6 is an explanatory diagram of a method for detecting electric power line energization according to another embodiment of the present invention.

FIG. 7 is a cross-sectional view of a conventional electronic voltage detector.

FIG. 8 is a block diagram of a conventional electronic voltage detector.

[Explanation of symbols]

 2 detection electrode 7 LED 10 battery 20 bias voltage generation circuit 21 level determination circuit 22 display circuit 12 electric circuit

 ─────────────────────────────────────────────────── ─── Continuation of the front page (56) Bibliography Sho 49-55075 (JP, U) Steady Sho 56-23462 (JP, U) Steady Sho 51-145960 (JP, U)

Claims (1)

[Scope of utility model registration request] 1. A detection electrode for detecting the presence or absence of electric charge in an electric circuit, a level judgment circuit for detecting the electric charge detected by the detection electrode, and a threshold voltage output as a bias voltage of the level judgment circuit. An electronic device equipped with a bias voltage generating circuit that also serves as an electronic switch for self-circuit test of the device, and a display circuit for displaying the above-mentioned voltage application by blinking and lighting the LED and battery capacity and self-circuit test display by continuously lighting the LED. Type voltage detector.