JPH021678Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to an improvement in a device for reading measured values of a measuring instrument from a remote location.

With meters for automatic meter reading that use telephone lines, etc., the transmission cable is directly connected to the electronic circuit inside the meter with a connector, so meters that are submerged in water, such as water meters, require expensive waterproof connectors. However, when the connectors were attached and detached on-site, dirt and other substances could get in, making it difficult to improve reliability.
In addition, external electrical noise is transmitted from the cable into the measuring instrument, which has the disadvantage of causing malfunctions and breakdowns in electronic measuring instruments.

The purpose of this invention is to propose a remote readout device free from such drawbacks, which will now be explained based on embodiments.

In FIG. 1, reference numeral 10 is a water meter serving as a meter, and a light projecting/receiving unit 20 is removably mounted on the upper surface of a glass 11 located above the water meter. As shown in FIGS. 2 and 3, the light projecting unit 20 includes a cable 21, an issuing means (a light emitting diode in the embodiment) 22 for projecting a light transmission command, and a transmission means (a phototransistor in the embodiment) 23b. is provided. The water meter 10 converts the electrical pulses generated by the rotation of the impeller 12 into pulses for each unit flow rate and performs integral counting, and when it receives a transmission command, it starts up and converts the measured value into a series ON/OFF signal convenient for transmission. an instruction unit 13 having an electronic circuit for transmitting and a liquid crystal display for displaying measured values, a transmitting means (liquid crystal in the embodiment) 14 for changing the serial ON/OFF signal to brightness or darkness of an object such as a liquid crystal, and the transmitting command. It is equipped with a command receiving means (a phototransistor in the embodiment) 15 for receiving light, converting it into an electric signal, and transmitting it to an electronic circuit, a printed circuit board 16, and the like. The transmitting means 14 is formed integrally with a liquid crystal panel 17 that displays the measured value numerically, and its mode is shown in FIG. 4. Part 17 of liquid crystal panel 17
A is transparent so that light passing through this portion can reach the command receiving means 15 located below it (FIG. 4).

Figure 5 shows the case of a water meter that has a mechanical indicator that displays measured values.
4, and command receiving means 15 using a phototransistor
are arranged so that they can be seen through the cutouts 14' and 15' of the dial.

FIG. 6 is a diagram explaining the function of the measuring instrument of the embodiment shown in FIGS. 1 to 4. The rotation of the impeller 12 is controlled by the magnetic sensor 18 placed close to the permanent magnet 12a attached to the upper end of the shaft. The amount of water used is converted into pulses and counted by an electronic circuit 19 having an electronic counter and an arithmetic processing section, and the amount of water used is displayed on the liquid crystal panel 17 in six decimal digits. When the command receiving means (phototransistor) 15 receives the transmission command, the electronic circuit 19 serially transmits the measured value.
The transmitting means (liquid crystal) 14 is made to blink by using an ON/OFF signal.

FIG. 7 shows the entire circuit including the reading board of the above embodiment, and shows the reading switch 3 of the reading device 30.
1 is closed, the voltage of the battery 32 is applied via resistors R ₁ and R ₂ to the issuing means (light emitting diode) 22 and the light emitting means (light emitting diode) 23a of the light emitting transmission means 23, lighting up both light emitting diodes. . Then, the command receiving means (phototransistor) 1 of the measuring instrument 10
5 operates and sends a start signal to the electronic circuit, converts the measured value into a serial ON/OFF signal, and causes the transmitting means (liquid crystal) 14 to blink, giving a change in brightness and darkness. The light from the light projecting means 23a is projected onto the transmitting means, and the transmission means 23b receives the reflected light and transmits the light in the series.
The current flowing through the cable 21 is increased or decreased according to the brightness or darkness according to the ON/OFF signal. 24 is a FET transistor for current limiting. The current in the cable is detected by the detection circuit 33 as a voltage drop across the resistor _R1 , and a measured value is received. As shown in FIG. 8, the light projection and transmission means 23 uses a known device that has an integral structure of a light emitting diode 23a and a phototransistor 23b. Resistor R ₁ is equal to resistor R ₂ or
The resistance value is set to be relatively small compared to that of the FET transistor 24.

FIG. 9 shows an example of a circuit different from that in FIG. 7, and when the readout switch 31 is switched to the illustrated position, the transistor
_Q1 becomes conductive, the issuing means 22 and the light emitting means 23a emit light, and the transmitting means 23b operates according to the brightness of the transmitting means of the measuring instrument (not shown), and the transistor
By turning Q ₂ on and off, the current in the cable 21 is increased or decreased, and the measured value is transmitted to the reading device 30.

FIG. 10 shows an example in which an optical fiber is used in the middle, including a light emitting diode 34 that converts the activation signal of the reading device into light, a liquid crystal segment (transmission means) 14, and a phototransistor (command receiving means) 15.
The optical fibers 21b and 21a transmit the brightness of the liquid crystal segment 14 to the phototransistor 35, and the optical fibers 21a to 21c can transmit the measured values. In this embodiment, the tip 21a' of the optical fiber 21a acts as a means for projecting a transmission command, and the tip 21c' of the optical fiber 21c acts as a means 23b for transmitting changes in the amount of light due to the brightness and darkness of the liquid crystal segment (transmission means) 14. act.

FIG. 11 shows a water meter using a solar cell as the command receiving means 15, which eliminates the need for electric power for receiving light and allows the generated energy to be used as signal transmission energy to the electronic circuit.

In FIG. 12, a light emitting diode is used as the transmitting means 14 of the water meter 10, and since the response is faster than that of a liquid crystal, measured values can be transferred quickly. Although light-emitting diodes consume a larger amount of current than liquid crystals, their quick response makes it possible to shorten the light emitting time and reduce power consumption to some extent.

As is clear from the above explanation, according to this invention, even when the measuring instrument is used in a submerged environment, the cable can be attached and detached without any problem, and the cable and the measuring instrument are electrically isolated. This eliminates the risk of malfunctions caused by electrical noise.

[Brief explanation of the drawing]

The drawings show an example of this invention; Figure 1 is a slope view;
Fig. 2 is a perspective view of the light emitter/receiver unit, Fig. 3 is a vertical sectional view, Fig. 4 is a top view of the water meter, Fig. 5 is a top view of a water meter of a different embodiment, and Fig. 6 is a top view of the water meter. 7 and 9 are electrical circuit diagrams; FIG. 8 is a diagram showing an example of the light transmission means;
Figure 0 is a perspective view of the main part of another embodiment, Figure 11 and Figure 1.
FIG. 2 shows the main parts of an electric circuit of a further different embodiment. 10... Water meter (measuring instrument), 11... Glass, 14... Transmitting means, 15... Order receiving means, 19
...Electronic circuit, 20... Light emitting/receiving unit, 21...
... Cable, 21a, 22... Projection means, 23b
...Transmission means.

Claims (1)

[Scope of claims for utility model registration] 1 Glass for reading the display of measurement values from the outside 1
1, a command receiving means 15 receives the transmitted command, converts it into an electric signal, and transmits it to the electronic circuit; The electronic circuit that transmits as an OFF signal and the series ON/OFF
Transmission means 1 that changes the signal to brightness or darkness of an object such as a liquid crystal
4 is provided in the measuring instrument, and the command receiving means 1
5 and a transmitting means 14 are disposed opposite to the glass 11, and a means 22 for projecting a transmitting command by light onto the command receiving means 15, and a means 22 for receiving a weighing value signal based on the brightness of the transmitting means 14 and transmitting this signal in the form of light. Alternatively, a light emitting/receiving unit 20 equipped with a means 23b for converting into an electric signal and transmitting it is provided, and the light emitting/receiving unit 20 is placed opposite the command receiving means 15 and the transmitting means 14 from the outside of the glass 11 to form a measuring instrument. A removable optically coupled isolated readout device. 2. The optically coupled isolated readout device according to claim 1, wherein a solar cell is used as the order receiving means 17 in the measuring instrument. 3 Claim No. 1 for Utility Model Registration Using a Light Emitting Diode as the Transmitting Means 14 in the Measuring Instrument
The optically coupled remote readout device described in 2.