JPS6377325A - Electronic measuring instrument - Google Patents

Abstract

(57) [Abstract] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention relates to electronic measuring instruments, in particular, in which two or more types of power sources can be used, and one of the power sources is a battery with a relatively large capacity, such as a battery. It is possible to use a small one.

<Prior Art> Electronic measuring instruments are often comprised of an analog circuit that amplifies a signal from a sensor and performs AD conversion, and a digital circuit such as a microcomputer that processes the AD converted data. And for high precision measurement, “
It is called a "warming amplifier" and requires energization for several to several tens of minutes before use, especially in order to stabilize the characteristics of the analog circuit.

<Problems to be Solved by the Invention> In order to eliminate the above-mentioned wasted time during warm-up, in conventional devices that use a commercial power supply, current is passed through at least the analog circuit.

However, if a battery is used as a power source, such as in a vortaple electronic measuring instrument, it is not possible to constantly supply current to the analog circuit due to the lifespan of the battery.

On the other hand, in portable electronic measuring instruments, for example, AC
Some devices allow the use of commercial power through an adapter. In this case, more accurate measurements can be made by constantly supplying current to the analog circuit, but conventionally, this type of measuring instrument has been designed to be able to supply electricity at all times even when using commercial power as well as when using batteries. There wasn't. For this reason, when using a commercial power source, warming up is required for high precision measurement, even though there is no concern about the life of the power source.

<Means for Solving the Problems> The present invention provides an electronic measuring instrument that has an analog circuit and a digital circuit and can selectively use a large-capacity power source A and a small-capacity power source B. A first switch means for switching the power supply to the analog circuit, a second switch means for switching the power supply to the digital circuit, and a determination means for determining whether the power supply in use is a power supply A or a power supply B. When power source A is used, the first switch means is turned on regardless of the second switch means, and power source B is turned on.
When the second switch means is in the off state, the first switch means is turned off when the second switch means is in the off state.

<Function> The electronic measuring instrument according to the present invention constantly supplies power to the analog circuit regardless of the state of the digital circuit when power supply A is used, and when power supply to the digital circuit stops when power supply B is used, power is supplied to the analog circuit. will also stop.

<Example> Hereinafter, one embodiment of the present invention will be described based on the drawings.

In the figure, A is a power supply with a relatively large capacity, and B is a power supply with a relatively small capacity. Reference numeral 1 denotes an electronic measuring instrument, and this electronic measuring instrument 1 includes a determination section 2, a control section 3. Switch 4. Power switch5. Sensor 6, analog circuit 7. It is composed of a digital circuit 8 and a display section 9. The electronic measuring instrument 1 can selectively use power source A and power source B. Power supply A is
For example, a commercial power source 1 generator, solar battery, etc.

Further, the power source B is, for example, a dry battery, a storage battery, or the like.

Power is supplied from the power supply A or power supply B to the sensor 6 and analog circuit 7 via the determination section 2 and switch 4, and further to the digital circuit 8 and display section 9 through the determination section 2 and power switch 5.

The determination unit 2 serves as a power supply path and determines which of the power sources A and B is currently supplying power to the electronic measuring instrument 1. The control unit 3 controls the switch 4 in accordance with the determination result of the determination unit 2 and the state of the power switch 5. Switch 4 cuts off and on the power supply to sensor 6 and analog circuit 7 .

The power switch 5 cuts off and on the power supply to the digital circuit 8 and the display section 9 .

The sensor 6 converts the measured quantity of the measurement target into an electrical signal.

The analog circuit 7 includes an amplifier that amplifies the analog output of the sensor 6 and an A that converts the output of the amplifier into digital data.
It consists of a D converter, etc. This analog circuit 7 is
This circuit has a tendency that the longer the energization time is, the better the measurement accuracy of the electronic measuring instrument 1 becomes. The digital circuit 8 is composed of a microcomputer or the like that processes the measurement data AD-converted by the analog circuit 7 according to a predetermined program. The display section 9 displays the measurement data processed by the digital circuit 8.

The operating procedure will be explained below.

The control unit 3 controls the switch 4 according to the four procedures shown in Table 1, depending on the type of power source in use and the state of the power switch 5.

In step (2) in Table 1, when the determining unit 2 determines that the power source in use is the power source A and the power switch 5 is in the on state, the switch 4 is turned on. This is the case, for example, when using this electronic measuring instrument using a commercial power supply, where the sensor 6° analog circuit 7. Digital circuit 8
Also, power is supplied to all of the display section 9.

In step (2), if the power source in use is the power source A and the power switch 5 is in the off state, the switch 4 is turned on. This is the case, for example, when commercial power is used but the electronic measuring instrument is not used. In this case, only the sensor 6 and analog circuit 7 are powered.

That is, since warming-up is always completed, high-precision measurement is possible immediately when the power switch 5 is turned on. Moreover, since power supply A is used, there is no need to worry about the lifespan of the power supply.

In this manner, when the large-capacity power supply A is used, the switch 4 is turned on regardless of the state of the power switch 5, and the analog circuit 7 is constantly supplied with power.

In step (2), when the determining section 2 determines that the power source in use is the power source B and the power switch 5 is in the on state, the switch 4 is turned on. This is the case, for example, when using this electronic measuring instrument with a dry battery as a power source, where the sensor 6° analog circuit 7. Digital circuit 8
Also, power is supplied to all of the display section 9.

In step (2), if the power source in use is power source B and the power switch 5 is in the off state, the switch 4 is turned off. This is the case, for example, when dry batteries are used as a power source, but this electronic measuring instrument is not used. In this case, the sensor 6, analog circuit 7. No power is supplied to the digital circuit 8 and all the circuits of the display section 9, so that the power supply is not consumed.

In the above-described embodiment, the determining unit 2 determines whether the power source in use is power source A or power source B. You may also input it using a method. This electronic measuring device only needs to be equipped with means for determining the result of detecting the type of power source. Further, in the above embodiment, the power switch 5 is turned on when the power source A is used.

Although it is possible to turn off the power switch 5, the power switch 5 may be always in the on state when the power source A is used.

However, in this case, there may be a problem with the life of the display device.

<Effects of the Invention> As explained above, in the present invention, when a large-capacity power source is used, power is constantly supplied to the analog circuit even when the electronic measuring instrument is not in use, and when a small-capacity power source is used, the electronic Since power is not supplied to the analog circuit when the analog measuring instrument is not in use, high-accuracy measurements can be made quickly without the need for warming up in locations where large-capacity power sources such as commercial power sources are readily available. If a large-capacity power supply is not available, high precision cannot be obtained quickly, but high precision measurement can be performed with the minimum amount of power required, which is very useful in practical use.

[Brief explanation of the drawing] The drawing is a block diagram showing the configuration of an embodiment of the present invention. 1...Electronic measuring instrument 2-・-judgment section 3...-control unit 4~ Switch 5-Power switch 6-・-sensor 7-Analog circuit 8...-Digital circuit 9-・Display section A, B・-Power supply

Claims (1)

[Claims] In an electronic measuring instrument that has an analog circuit and a digital circuit and can selectively use a power source A with a relatively large capacity and a power source B with a relatively small capacity, there is a step for switching the power supply to the analog circuit. 1 switch means, a second switch means for switching the power supply to the digital circuit, and a power supply in use is the power supply A.
and a determining means for determining which of the power source B and the power source B is selected.
In accordance with the judgment of this judgment means, when power source A is used, the first switch means is turned on regardless of the state of the second switch means, and when power source B is used, the second switch means is turned off and the first switch means is turned on. An electronic measuring instrument characterized by comprising: switching control means for turning off the switch means.