JP5740185B2 - Probe device for electrical measuring instrument and electrical measuring instrument - Google Patents

Description

  The present invention relates to an electrical measuring instrument probe device and an electrical measuring instrument used in a digital multimeter or the like, and more particularly to a connector as a connection device.

  Some probe devices used in digital multimeters and the like have a light that irradiates light to the tip of the probe pin and an operation switch that gives an instruction signal to the measuring instrument body (DMM) in consideration of operability. . An external appearance of an example of the conventional apparatus is shown in FIG. 3, and a circuit configuration diagram is shown in FIG. 4, which will be described.

  According to this, the probe device 1 includes an elongated cylindrical grip 2 that is gripped by a measurement operator, and a connector 3 is connected to the rear end of the probe device 1 via an electric cable 4. The connector 3 is detachably connected to a measuring instrument main body (not shown).

  A probe pin 5 that detects an electrical signal from a measurement object (not shown) and an illumination light-emitting diode 6 as a light that irradiates light toward the tip of the probe pin 5 are provided on the distal end side of the grip 2. Yes. Further, an operation switch 7 is provided on the upper surface side of the grip 2, for example.

  As shown in FIG. 4, in the connector 3, a control signal for giving an instruction signal from the output terminal 5a of the probe pin 5, the power supply terminals 6a and 6b to the light emitting diode 6 for illumination, and the operation switch 7 to the control unit of the measuring instrument body. Output terminals 7a and 7b are provided.

  The operation switch 7 is an on / off switch, and in this example, is configured as an interlocking switch that also serves as a switch for turning on / off the light emitting diode 6 for illumination.

  Although not shown, the probe device 1 has a common-side probe pin used as a pair with the probe pin 5, and the common-side probe pin is connected to the common terminal of the measuring instrument main body separately from the connector 3. The

  By connecting the connector 3 to the measuring device main body, power is supplied from the measuring device main body to the light emitting diode 6 via the power supply terminals 6a and 6b, and the probe pin 5 is connected to the measuring device via the output terminal 5a. The control signal output terminals 7a and 7b are connected to the control unit in the measuring instrument main body.

  As an example of the operation, when the operation switch 7 is turned on, a measurement start signal is given to the control unit in the measuring instrument body, and the illumination light emitting diode 6 is turned on. In addition, an electrical signal (measurement signal) of the measurement object detected by the probe pin 5 is taken into a measurement unit in the measurement device main body via the A / D converter.

  When the operation switch 7 is turned off at the end of measurement, the illumination light emitting diode 6 is turned off, a hold signal is output from the control unit to the measurement unit, and the measurement data captured by the measurement unit is held. A predetermined measurement calculation process is performed. Patent document 1 is mentioned as an example of such a probe apparatus.

JP 2009-121877 A

  When the illumination light emitting diode 6 and the operation switch 7 are provided as in the conventional example, the connector 3 includes the power supply terminals 6a and 6b for the illumination light emitting diode 6 in addition to the output terminal 5a for the probe pin 5. Since the control signal output terminals 7a and 7b for the operation switch 7 are provided, the structure of the connector 3 is complicated.

  In addition, since the power supply terminals 6a and 6b are particularly present, a predetermined creepage separation distance is required in view of safety, which makes the connector 3 large. Moreover, there is a problem that the risk of poor contact increases due to an increase in the number of terminals.

  Accordingly, the first object of the present invention is to reduce the size and simplification of the connector connected to the main body of the measuring instrument in the probe device having the light emitting diode for probe pin illumination and the operation switch for measurement control, and to make the connection reliable. Is to increase. A second problem of the present invention is to reliably prevent malfunction caused by ambient light entering from the connector portion in an electrical measuring device having a measuring device main body and a probe device connected to the measuring device main body via a connector. There is.

In order to solve the first problem described above, the invention according to claim 1 includes a connector detachably connected to a measuring instrument body including a control unit and a measuring unit, and a probe pin for detecting an electrical signal from a measured object. An illumination light emitting diode that emits light toward the tip of the probe pin; and an operation switch that controls driving of the illumination light emitting diode and provides a predetermined instruction signal to the control unit. In the measuring instrument probe device,
The connector includes a built-in battery as a power source, and the connector includes a first connection unit that supplies the electrical signal detected by the probe pin to the measurement unit, and the instruction signal from the operation switch to the control unit. A transmission light-emitting diode that transmits the instruction signal as an optical signal to the control unit, and the illumination light-emitting diode and the transmission light-emitting diode. The transmission power source is obtained from the built-in battery , and the transmitting light emitting diode is driven by an oscillation circuit having a constant oscillation frequency .

The invention according to claim 2, Oite to claim 1, the connector is characterized in that it further comprises a connector mounting confirmation means for confirming that it is mounted on the instrument body.

According to a third aspect of the present invention, in the second aspect , a magnetic sensor is used as the connector mounting confirmation means.

According to a fourth aspect of the present invention, in any one of the first to third aspects, the operation switch includes an on / off switch, and the illumination light emitting diode is turned on when the operation switch is turned on and turned off when the operation switch is turned off. The instruction signal is transmitted to the controller when the switch is on and / or off.

In order to solve the second problem described above, an invention according to claim 5 includes a measuring instrument body including a control unit and a measuring unit, and a probe device having a connector detachably connected to the measuring instrument body. The probe device includes a probe pin for detecting an electrical signal from the measurement object, an illumination light emitting diode for irradiating light toward the tip of the probe pin, and driving of the illumination light emitting diode, An operation switch for providing a predetermined instruction signal to the control unit is provided, and the connector includes a first connection means for supplying the electrical signal detected by the probe pin to the measurement unit, and the operation switch. In the electrical measuring instrument including the second connection means for transmitting the instruction signal by the control unit to the control unit,
The second connecting means comprises a photocoupler including a transmitting light emitting diode provided on the probe device side and a light receiving element provided on the measuring device main body side, and the probe device includes a built-in battery as a power source. A drive power source for the illumination light-emitting diode and the transmission light-emitting diode is obtained from the built-in battery. On the probe device side, the transmission light-emitting diode is driven by an oscillation circuit having a constant oscillation frequency, and the measurement is performed. The control unit on the instrument body side is characterized in that when the frequency of the received signal of the light receiving element is the same as the oscillation frequency, it is determined that the probe device is connected to the measurement instrument body .

The invention according to claim 6 further comprises a connector attachment confirmation means for confirming that the connector is attached to the measuring instrument main body according to claim 5, wherein the control unit is configured such that when the connector is not attached. The output of the light receiving element is invalidated.

The invention according to claim 7 is characterized in that, in claim 6 , a magnetic sensor using a permanent magnet provided on the connector side as an object to be detected is used for the connector mounting confirmation means.

According to an eighth aspect of the present invention, in any one of the fifth to seventh aspects, the operation switch is an on / off switch, and the light emitting diode for lighting is turned on when the operation switch is turned on and turned off when the operation switch is turned off. The instruction signal is transmitted to the control unit when the switch is turned on and / or off, and the control unit obtains measurement data from the measurement unit based on the instruction signal and executes a predetermined measurement process. Yes.

  According to the probe device for an electric measuring instrument according to claim 1 of the present invention, the second connection in the connector is provided with a built-in battery as a power source and transmits an instruction signal from the operation switch to the control unit on the measuring instrument main body side. As a means, a transmission light-emitting diode that transmits the instruction signal as an optical signal to the control unit is used, and a drive power source of the light-emitting diode for probe pin illumination and the light-emitting diode for transmission is obtained from a built-in battery. The connection means with the measuring instrument main body provided in the inside is only the first connecting means for giving the electrical signal detected by the probe pin to the measuring section on the measuring instrument main body side, and the transmitting light emitting diode (second connecting means). This eliminates the need for a power supply terminal from the measuring instrument body side to the light emitting diode for illumination. And together may simplify, it is possible to improve the reliability of the connection.

  According to an electric measuring instrument of the present invention, a light receiving element that is a counterpart of the transmitting light emitting diode is provided on the measuring instrument main body side in combination with the probe device for an electric measuring instrument according to claim 1. The transmitting light emitting diode is driven by an oscillation circuit having a constant oscillation frequency. When the frequency of the reception signal of the light receiving element is the same as the oscillation frequency, the probe is connected to the measuring instrument body. 9. The control unit according to claim 8, further comprising connector mounting confirmation means for determining that a device is connected and confirming that the connector is mounted on the measuring instrument body. In this case, by making the output of the light receiving element invalid, it is possible to reliably prevent malfunction due to disturbance light entering the light receiving element.

The schematic diagram which shows 1st Embodiment of this invention. The schematic diagram which shows 2nd Embodiment of this invention. FIG. 2 is an external view showing a conventional example having a light for irradiating light to a tip of a probe pin and an operation switch for giving an instruction signal to a measuring instrument main body in an electric measuring instrument probe apparatus. The circuit block diagram which shows the said prior art example.

  Next, the first embodiment of the present invention will be described with reference to FIG. 1 and the second embodiment of the present invention will be described with reference to FIG. 2, but the present invention is not limited to this.

  FIG. 1 shows an electrical measuring instrument including a probe device 10 and a measuring instrument body 20 according to the first embodiment of the present invention.

  The probe device 10 includes a probe main body 10A and a connector 10B that can be attached to and detached from the measuring instrument main body 20, and these are connected via an electric cable 10C. The probe body 10A, the connector 10B, and the electric cable 10C correspond to the grip 2, the connector 3, and the electric cable 4 in FIG. 3, respectively.

  The probe body 10A is provided with a probe pin 11 for detecting an electrical signal (measurement signal) such as voltage, resistance, and current from a measured object (not shown), and an output terminal 11a of the probe pin 11 is provided on the connector 10B. Is provided.

  The probe pin 11 and the output terminal 11a are connected via a predetermined wiring in the electric cable 10C. For example, a banana plug (common name) may be used for the output terminal 11a. In actual measurement, a probe pin on the common side (hereinafter sometimes referred to as a common probe pin) is used together with the probe pin 11, but the illustration of the common probe pin is omitted.

  Further, the probe main body 10A incorporates a battery 12 as a power source. Between the positive electrode side and the negative electrode side of the battery 12, an operation circuit 13, an illumination circuit 14, a one-shot circuit 15, an oscillation circuit 16, and a transmission circuit 17 for the measuring instrument body 20 are connected in parallel. ing.

  The operation circuit 13 includes a series circuit of an operation switch 13a and a current limiting resistor R1. In this embodiment, the operation switch 13a is a normally open type on / off switch that is turned on at the start of measurement and turned off at the end of measurement by the measurement operator.

  The illumination circuit 14 includes an illumination light emitting diode 14a, a current limiting resistor R2 and a switching transistor 14b in series. The base of the switching transistor 14b is turned on / off of the operation switch 13a via a base resistor R3. A signal is applied.

  The light emitting diode 14a irradiates light toward the pin tip of the probe pin 11 when the light emitting diode 14a is turned on, similarly to the light emitting diode 6 for illumination described with reference to FIG.

  The one-shot circuit 15 and the oscillation circuit 16 have their respective power terminals connected to the positive electrode and the negative electrode of the battery 12 to obtain drive power from the battery 12.

  The one-shot circuit 15 operates using an operation signal (ON signal or OFF signal) from the operation switch 13a as a trigger signal, and outputs a pulse signal (rising pulse signal in this example) to the oscillation circuit 16 for a predetermined time. After a predetermined time elapses, the pulse signal disappears.

  The oscillation circuit 16 generates a pulse having a predetermined frequency while the pulse is output from the one-shot circuit 15. In this embodiment, the trigger signal of the one-shot circuit 15 by the operation switch 13a is supplied via the illumination circuit 14.

  The transmission circuit 17 includes a light emitting diode 17a for transmission, a current limiting resistor R4, and a switching transistor 17b in series. A pulse having a predetermined frequency is applied from the oscillation circuit 16 to the base of the switching transistor 17b, whereby the light emitting diode 17a blinks based on the pulse having the predetermined frequency.

  In the present invention, the transmission circuit 17 is provided in the connector 10B together with the output terminal 11a of the probe pin 11, and is connected to the battery 12 via a predetermined power supply wiring in the electric cable 10C.

  The measuring device main body 20 includes a control unit 21 and a measuring unit 22. In addition, a display unit for displaying measurement values and the like, and function keys for operation are provided, but these are not shown. The measuring device main body 20 preferably has a function equivalent to, for example, a digital multimeter (DMM).

  The measuring instrument main body 20 has a receptacle 23 which is the counterpart of the output terminal 11a of the probe pin 11. The measurement signal detected by the probe pin 11 is transmitted from the receptacle 23 to the measuring instrument main body 20, and is not shown in the figure. The data is taken into the measuring unit 22 via the D converter.

  The measuring instrument main body 20 includes a receiving circuit 24 that is a counterpart of the transmitting circuit 17. In this embodiment, the reception circuit 24 includes a phototransistor 24 a, and a reception signal of the phototransistor 24 a is given to the control unit 21.

  For measurement, first, the connector 10B is attached to the measuring device main body 20. As a result, the output terminal 11a of the probe pin 11 is connected to the receptacle 23, and a photocoupler composed of an optical combination of the light emitting diode 17a of the transmission circuit 17 and the phototransistor 24a of the reception circuit 24 is configured. Further, a common probe pin (not shown) is connected to a common terminal (not shown) of the measuring device main body 20.

  Next, the probe pin 11 and the common probe pin are brought into contact with a predetermined part of the measurement object, and the operation switch 13a is pressed to turn it on. As a result, a predetermined base voltage is applied to the base of the switching transistor 14b, the switching transistor 14b is turned on, and the light emitting diode 14a for lighting is turned on. In addition, after pressing the operation switch 13a and turning on the light emitting diode 14a, each probe pin may be brought into contact with the object to be measured.

  Thereafter, the operation switch 13a is released to turn it off. As a result, the light emitting diode 14a for illumination is turned off, a trigger signal is input to the one-shot circuit 15, and a rising pulse signal is output from the one-shot circuit 15 for a predetermined time.

  While a pulse signal is output from the one-shot circuit 15, a pulse signal having a predetermined frequency is applied from the oscillation circuit 16 to the base of the switching transistor 17b, and thereby the light emitting diode 17a for transmission blinks.

  On the measuring instrument main body 20 side, the flashing signal from the light emitting diode 17a for transmission is received by the phototransistor 24a, and the received light signal is given to the control unit 21.

  If the received light signal is a clock signal having the same frequency as the oscillation frequency of the oscillation circuit 16, the control unit 21 determines that the probe device 10 is connected to the measuring instrument body 20 and the operation switch 13a is turned off. Then, the measurement data captured by the measurement unit 22 is held, a predetermined calculation process is executed, and the result is displayed on a display unit (not shown).

  In this way, by transmitting a control signal (operation switch signal) between the probe device 10 and the measuring instrument main body 20 with an optical clock pulse of a predetermined frequency, it is possible to determine whether the probe device 10 is connected or not. The control signal can be reliably transmitted.

  Further, when a normal probe pin (a probe pin similar to a common probe pin having no light or an operation switch) is inserted into the receptacle 23 and used, the phototransistor 24a is exposed to disturbance light. Malfunctions due to light can also be prevented.

  Next, a second embodiment of FIG. 2 will be described. The difference from the first embodiment is that the oscillation circuit 16 is omitted, and that the probe device 10 is determined to be connected / not connected by a magnetic sensor. It may be the same as one embodiment.

  As shown in FIG. 2, in the second embodiment, the switching transistor 17b in the transmission circuit 17 is directly driven by the output pulse of the one-shot circuit 15 (rising pulse output for a predetermined time).

  Further, the permanent magnet 18 is provided in the connector 10B. On the other hand, a magnetic sensor 25 having the permanent magnet 18 as a detected body is provided on the measuring instrument main body 20 side. For example, a Hall element may be used for the magnetic sensor 25.

  Prior to the measurement, when the connector 10 </ b> B is connected to the measuring instrument main body 20, the presence of the permanent magnet 18 is detected by the magnetic sensor 25, and the detection signal is input to the control unit 21. Thereby, the control unit 21 determines that the probe device 10 is connected to the measuring instrument main body 20, and treats the light reception signal from the phototransistor 24a as valid.

  As in the first embodiment, when the probe pin 11 and the common probe pin are brought into contact with a predetermined part of the measurement object and the operation switch 13a is pressed to turn on, a predetermined base voltage is applied to the base of the switching transistor 14b. The switching transistor 14b becomes conductive, and the light emitting diode 14a for lighting is turned on. In addition, after pressing the operation switch 13a and turning on the light emitting diode 14a, each probe pin may be brought into contact with the object to be measured.

  Thereafter, when the operation switch 13a is released and turned off, the illumination light emitting diode 14a is turned off and a trigger signal is input to the one-shot circuit 15, and a rising pulse signal is output from the one-shot circuit 15 for a predetermined time. The

  In the second embodiment, when the rising pulse signal is applied to the base of the switching transistor 17b, the light emitting diode 17a for transmission is turned on while the pulse signal is output from the one-shot circuit 15.

  On the measuring instrument main body 20 side, a lighting signal from the light emitting diode 17a for transmission is received by the phototransistor 24a, and the received light signal is given to the control unit 21. As a result, the control unit 21 determines that the operation switch 13a has been turned off, holds the measurement data captured by the measurement unit 22, executes a predetermined calculation process, and displays the result on a display unit (not shown). .

  When the detection signal of the permanent magnet 18 is not output from the magnetic sensor 25, the control unit 21 determines that the probe device 10 is not connected, and invalidates the light reception signal output from the phototransistor 24a. .

  As a result, as described in the first embodiment, it is possible to prevent malfunction due to disturbance light when a normal probe pin is used.

  In the first and second embodiments, when the operation switch 13a is turned off, measurement data is held on the measuring instrument main body 20 side. However, when the operation switch 13a is turned off. It is also possible to hold the measurement data.

  According to the first and second embodiments, the battery 12 is built in the probe body 10A, and the drive power for the light emitting diode 14a for probe pin illumination and the light emitting diode 17a for transmission is obtained from the built-in battery 12. As a result, the connector 10B does not require a power supply terminal from the measuring instrument body 20 side, so that the connector can be reduced in size and simplified, and the connection reliability can be increased.

  In the first embodiment, an optical clock pulse having a predetermined frequency is used as a transmission medium for a control signal (operation switch signal) between the probe device 10 and the measuring instrument main body 20. Thus, it is possible to reliably determine whether the connection is 10 or not and to transmit a control signal, and to prevent malfunction due to disturbance light when a normal probe pin is used.

  In the second embodiment, the connector mounting confirmation unit including the permanent magnet 18 and the magnetic sensor 25 is provided. When the probe device 10 is not connected, the light reception output from the phototransistor 24a serving as the light receiving element. By treating the signal as invalid, it is possible to prevent malfunction due to disturbance light when a normal probe pin is used, as in the first embodiment.

DESCRIPTION OF SYMBOLS 10 Probe apparatus 10A Probe main body 10B Connector 10C Electric cable 11 Probe pin 12 Battery 13 Operation circuit 13a Operation switch 14 Illumination circuit 14a Illumination light emitting diode 14b Switching transistor 15 One-shot circuit 16 Oscillation circuit 17 Transmission circuit 17a Transmission light emitting diode 17b Switching Transistor 18 Permanent magnet 20 Measuring instrument body 21 Control unit 22 Measuring unit 23 Receptacle 24 Receiving circuit 24a Phototransistor 25 Magnetic sensor

Claims (8)

A connector detachably connected to a measuring instrument body including a control unit and a measurement unit, a probe pin for detecting an electrical signal from a measured object, and an illumination light emitting diode for irradiating light toward the pin tip of the probe pin; In the probe device for an electric measuring instrument comprising an operation switch that controls the driving of the light emitting diode for illumination and gives a predetermined instruction signal to the control unit,
The connector includes a built-in battery as a power source, and the connector includes a first connection unit that supplies the electrical signal detected by the probe pin to the measurement unit, and the instruction signal from the operation switch to the control unit. The second connecting means for transmitting,
A light emitting diode for transmission that transmits the instruction signal as an optical signal to the control unit is used for the second connection means, and the driving light source of the light emitting diode for illumination and the light emitting diode for transmission is obtained from the built-in battery , The probe device for an electrical measuring instrument , wherein the transmitting light emitting diode is driven by an oscillation circuit having a constant oscillation frequency . 2. The probe device for an electrical measuring instrument according to claim 1, further comprising a connector attachment confirmation means for confirming that the connector is attached to the measuring instrument main body. 3. A probe device for an electric measuring instrument according to claim 2 , wherein a magnetic sensor is used as said connector mounting confirmation means. The operation switch includes an on / off switch, and the light emitting diode for lighting is turned on when the operation switch is turned on and turned off when the operation switch is turned on, and the instruction signal is transmitted to the control unit when the operation switch is turned on and / or off. The probe device for an electrical measuring instrument according to any one of claims 1 to 3 , wherein A measuring instrument main body including a control unit and a measuring unit; and a probe device having a connector detachably connected to the measuring instrument main body, the probe device including a probe pin for detecting an electrical signal from a measured object; An illumination light emitting diode that irradiates light toward the tip of the probe pin, and an operation switch that controls driving of the illumination light emitting diode and that gives a predetermined instruction signal to the control unit are provided, The connector includes first connection means for supplying the electrical signal detected by the probe pin to the measurement unit, and second connection means for transmitting the instruction signal from the operation switch to the control unit. The electrical measuring instrument
The second connecting means is composed of a photocoupler including a light emitting diode for transmission provided on the probe device side and a light receiving element provided on the measuring device main body side,
The probe device includes a built-in battery as a power source, and a driving power source for the illumination light emitting diode and the transmission light emitting diode is obtained from the built-in battery. On the probe device side, the transmission light emitting diode has an oscillation frequency. Is driven by a fixed oscillation circuit, and the control unit on the measuring instrument main body side connects the probe device to the measuring instrument main body when the frequency of the received signal of the light receiving element is the same frequency as the oscillation frequency. An electrical measuring instrument characterized by being judged to be. It further comprises a connector attachment confirmation means for confirming that the connector is attached to the measuring instrument body, and the control unit invalidates the output of the light receiving element when the connector is not attached. The electrical measuring instrument according to claim 5 . 7. The electrical measuring instrument according to claim 6 , wherein a magnetic sensor using a permanent magnet provided on the connector side as a detected body is used for the connector mounting confirmation means. The operation switch comprises an on / off switch, the light emitting diode for lighting is turned on when the operation switch is turned on and turned off when the operation switch is turned off, and the instruction signal is transmitted to the control unit when the operation switch is turned on and / or off. electric measuring instrument as claimed in any one of claims 5 to 7 wherein the control unit is characterized by executing a predetermined measurement processing to obtain measurement data from the measurement unit based on the instruction signal.

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