JPH049620A - Electronic balance - Google Patents

Abstract

PURPOSE:To save power consumption and to start weighing immediately after turning on a power supply by interrupting power supply also from a load cell and an A/D converter. CONSTITUTION:When a power supply switch 5 is turned on, a prescribed DC voltage is supplied from a power supply part 6 to a weighing part 1, the A/D converter 2 and an operation/display part 3. After the lapse of a prescribed time, a signal TB from a timer 34 is also turned to an 'L' level. Thereafter, a final auto-zero processing range AZ.C is set up, and when the difference ¦F¦ of counted data between E and A registers is ¦F¦<=AZ.C, auto-zero processing is executed, the contents of the A register are stored in the E register and zero is displayed on a display device 35. Thereby when the switch 5 is turned off, power supply can be interrupted from all of the weighing part 1, A/D converter 2 and operation/display part 3.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention is an electronic % scale with an auto-zero processing function. A weighing section with a load cell that converts the analog electricity from this weighing section into digital count data, an analog-to-digital converter that converts the analog electricity from this weighing section into digital count data, and calculates and processes the count data from this converter to display weight display data. It consists of a calculation means that generates a There are also known devices that cut off the power to the computing means 5 along with the display.

In other words, when the power is first turned on, load cells and analog/digital converters do not operate stably and drift occurs, so power is constantly supplied to the load cells and analog/digital converters to maintain operational stability. I'm letting you do it.

[Problems to be Solved by the Invention] However, such devices that constantly supply power to load cells and analog-to-digital converters consume large amounts of power, and especially when batteries are used as power sources, the life of the batteries is shortened. There were problems such as the need to frequently replace batteries.

Therefore, when the power switch is turned off, the power consumption of not only the calculation means and display, but also the load cells and analog-to-digital converters when not in use is zero, and the battery life is extended. It will be possible to achieve this.

However, when doing this, load cells and analog
When the power to the digital converter is first turned on, a state occurs in which the displayed data under no load is not stabilized at zero due to the occurrence of drift (12).Therefore, there is a problem in that measurement cannot be performed immediately after the power is turned on.

Therefore, the present invention can save power consumption by cutting off the power not only to the calculation means and display, but also to the input/output cell and analog/digital converter by turning off the power switch. The present invention aims to provide an electronic scale that can perform weighing immediately after turning on the power, thereby improving its practicality.

Furthermore, it is an object of the present invention to provide an electronic scale that can immediately and reliably display zero when no load is applied when weighing operations are performed continuously.

[Means for Solving the Problem] The invention corresponding to claim (1) provides a weighing section having a load cell that outputs an electrical signal corresponding to a load, and converting the analog electrical signal from the weighing section into digital count data. An analog-to-digital converter that converts the count data from this converter to a calculation means that generates weight display data by processing the count data from this converter, and a display when the count data input to this calculation means is within the preset auto-zero processing range. In an electronic scale consisting of an auto-zero processing means that forces the data to zero and a display that displays display data from the calculation means, turn on the power to the weighing section, analog-to-digital converter, calculation means, and display. , the power switch to be turned off and the auto-zero processing range of the auto-zero processing means are set to a large range immediately after the power switch is turned on, and the range is made smaller as time passes, and after a predetermined time elapses, the auto-zero processing range is controlled to the preset final auto-zero processing range. The system is equipped with auto-zero processing range control means.

In addition, the invention corresponding to claim (2) includes a power switch that turns on and off power to the weighing section, analog-to-digital converter, calculation means, and display, and a power switch that turns on and off the power to the weighing section, analog-to-digital converter, calculation means, and display, and An auto-zero processing range control means that immediately sets a large range, reduces the range as time passes, and controls the auto-zero processing range to a slightly wider range than a preset final auto-zero processing range after a predetermined time has elapsed; and this auto-zero processing range. Auto-zero processing in which the auto-zero processing range is switched to the final auto-zero processing range by the auto-zero processing range control means when count data exceeding the auto-zero processing range is input from the analog-to-digital converter after a predetermined time has elapsed under control by the processing range control means. A range switching means is provided.

The invention corresponding to claim (3) also includes a power switch that turns on and off the power to the weighing section, analog-to-digital converter, calculation means, and display, and a power switch that turns on and off the power to the weighing section, analog-to-digital converter, calculation means, and display, and that controls the auto-zero processing range of the auto-zero processing means when the power switch is turned on. An auto-zero processing range control means that sets a large range immediately afterward, reduces the range as time passes, and controls it to a preset final auto-zero processing range after a predetermined period of time, and an analog-to-digital converter that exceeds the auto-zero processing range. A weight stability detector that detects weight stability when count data is input;
After this weight stability detector detects weight stability, if the count data from the analog-to-digital converter falls below the forced zero range, which is set in a range wider than the auto-zero processing range, the display data is supplied from the calculation means to the display. A forced zero display control means is provided to set the value to zero.

[Operation] In the invention according to claim (1), when the power switch is turned off, the power to the weighing section, analog-to-digital converter, calculation means, and display is cut off.

When the power switch is turned on, the auto-zero processing range of the auto-zero processing means is initially set to a large range, and as time passes, the range becomes smaller, and after a predetermined time has passed, it becomes the final auto-zero processing range set in advance.

Therefore, even if the count data from the analog-to-digital converter fluctuates by a relatively large range due to drift that occurs in the weighing unit and analog-to-digital converter when the power is first turned on, the auto-zero processing range is set to a large range. Because of this, the displayed data when no load is applied can be reliably set to zero. Therefore, measurement can be performed immediately after power is turned on.

Furthermore, in the invention corresponding to claim (2), if the no-load state continues even after a predetermined time has elapsed after the power is turned on, the auto-zero processing range is slightly wider than the final auto-zero processing range set in advance. Since it is set to , the displayed data at no load can be set to zero more reliably. Then, after a predetermined period of time has elapsed, weighing is performed and count data exceeding the auto-zero processing range is input from the analog-to-digital converter, and thereafter the auto-zero processing range when no load is applied is switched to the final auto-zero processing range.

Moreover, in the invention corresponding to claim (3), when a predetermined period of time has elapsed after the power is turned on, the auto-zero processing range becomes the final auto-zero processing range. In addition, once the measurement is performed and stability is confirmed, when the measurement is finished and the load becomes unloaded, the count data from the analog-to-digital converter may fall below the forced zero range set in a range wider than the auto-zero processing range. Display data immediately becomes zero. Therefore, when the load state changes from a loaded state to an unloaded state, the load on the load cell does not immediately change to the unloaded state due to the influence of the frame that makes up the scale, so it takes a long time for the count data to return to the zero point count data. Even if this happens, the displayed data will immediately become zero, so you can start the next weighing immediately.
Becomes capable.

[Example〕 Hereinafter, one embodiment of the present invention will be described with reference to the drawings.

In Fig. 1, 1 corresponds to the load, and 2 is a weighing section that has a load cell that outputs an electrical signal and an amplifier that amplifies the electrical signal from the load cell, and 2 is an analog electrical signal from the weighing section 1. An analog-to-digital converter (hereinafter referred to as an A/D converter) that converts into digital count data, 3 is an operation unit that takes in count data from the A/D converter 2 and performs arithmetic processing and display processing.・It is a display part.

The calculation/display section 3 is a CPU that constitutes the main body of the control section.
(Central processing unit) 3], this CPU 31 controls each part;
It forms various registers and memristors such as read fist only memory) 32, A register, E register, and B register, and RAM (access memory) 33, timer 34, display 35, and this display 35. It is composed of a display register 36 and the like that stores small table data to be displayed.

Then, the power supply unit 6 is connected to the commercial power supply 4 via the power switch 5.
A predetermined DC voltage is supplied from the power supply section 6 to the weighing section], the A/D converter 2, and the calculation/display section 3.

The CPU 31, ROM 32, and RAM 33 are calculation means,
An auto-zero processing means that forcibly sets the display data to zero when the count data input to this calculation means is within a preset auto-zero processing range, and the auto-zero processing range of this auto-zero processing means is set to a large range immediately after the power switch is turned on. The auto-zero processing range control means configures an auto-zero processing range control means that sets the range as time passes, and controls the range to a preset final auto-zero processing range after a predetermined period of time has elapsed. Signals TA and TB are input from 34 at the timing shown in FIG. and said CP
U31 sets the auto-zero processing range to a relatively large range during the period when the signal TA is at H (high) level.
Z-A, and during the period when the signal TB is at the H level, the auto-zero processing range is slightly narrowed and set at AZ-B. The narrow preset final auto-zero processing range is set to AZ-C. (Auto-zero processing range control means) Furthermore, when the power switch 5 is turned on and the power is turned on, the CPU 31 performs the control shown in FIG. 3.

First, count data, which is digital data, is taken in from the A/D converter 2 and stored in the E register.

Subsequently, count data is taken in from the A/D converter 2 and stored in the A register.

Then, calculations are performed on the E register and the A register to obtain Fl.

Next, whether the signal TA is at H level or the signal TB is at H level.
Or check the L level for both signals TA and TB. 5.If the signal TA is at H level, then IFl>
Check whether it is AZ-A or not.

If F1≦AZ-A, it is determined that it is within the auto-zero processing range, and the contents of the A register are stored in the E register. Then, display data of zero is output to the display register 36. (
Auto zero processing means) Also, if IFI>AZ-A, A
The register start register is operated, and display data is created based on the result and output to the display register 36.

Furthermore, if the signal TB is at H level, then IF>AZ-B
Check whether or not.

If F1≦AZ-B, it is determined that it is within the auto-zero processing range, and the contents of the A register are stored in the E register. Then, display data of zero is output to the display register 36. (Auto-zero processing means) If lF1>AZ-B, the A register and the E register are operated, and display data is created based on the result and output to the display register 36.

Furthermore, if both signal TA and signal TB are at L level, then l
Check whether F l >AZ -C.

If F1≦AZφC, it is determined that it is within the auto-zero processing range, and the contents of the A register are stored in the E register. Then, display data of zero is output to the display register 36. (Auto-zero processing means) If IFI>AZ-C, the A register and the E register are operated, and display data is created based on the result and output to the display register 36.

When the display process is completed, the routine returns to taking in the count data from the A/D converter 2 and storing it in the A register.

In this embodiment with such a configuration, the power switch 5
When the power supply unit 6 turns on the weighing unit 1 and the A/D converter 2,
A predetermined DC voltage is supplied to the calculation/display unit 3.

First, the signal TA from the timer 34 becomes H level. During this period, the auto zero processing range is AZ-A.
If the difference IFI between the first count data taken into the E register and the second count data taken into the A register is IFI≦AZ-A, auto-zero processing is performed and the contents of the A register are stored in the E register. Zero display data is outputted to the display register 36 by register E and register 0, and zero is displayed on the display 35.

Also, during the period when this signal TA is at H level, IFI
>AZ-A, it is determined that weighing has been performed, and display data is created based on the weighing count data of the A register and the E register, and is displayed on the display 35.

After a certain period of time has elapsed, the signal TA from the timer 34 goes low and the signal TB goes high. However, during this period, the auto zero processing range is AZ - B.
(<AZ - A), and the difference IFI between the count data of the E register and the count data of the A register is IFI≦
If AZφB, auto-zero processing is performed and the contents of the A register are stored in the E register, zero display data is outputted to the display register 36 by the A register and E register 0, and zero is displayed on the display 35.

Also, during the period when this signal TB is at H level, IFI
>AZ-B, it is determined that weighing has been performed, and display data is created based on the weighing count data of the A register and the E register, and is displayed on the display 35.

When a predetermined period of time has elapsed since the power was turned on, the timer 34
The signal TB from the terminal also goes to L level. After that, the auto-zero processing range is the final auto-zero processing range AZ - C (
<AZ - B), and the difference IFI between the count data of the E register and the count data of the A register is IFI≦AZ
-C, auto-zero processing is performed and the contents of the A register are stored in the E register, zero display data is outputted to the display register 36 by the A register and E register 0, and zero is displayed on the display 35.

Further, when a state where IFl>AZ-C occurs, it is determined that weighing has been performed, and display data is created based on the weighing count data of the A register and the E register, and the display data is displayed on the display 3.
5.

In this way, by turning off the power switch 5, the weighing section 1
, the A/D converter 2, and the arithmetic/display section 3, all of which can be powered off, thereby reducing power consumption. Therefore, when the device is powered by a battery, the battery life can be extended.

Also, when the power switch 5 is turned on, the weighing section 1, A/D
Power is turned on to all of the converter 2 and calculation/display section 3. Immediately after the power is turned on, the operations of the weighing section 1 and the A/D converter 2 become unstable, and due to a large drift, the count data from the A/D converter 2 when no load is applied changes greatly. However, at this time, the auto zero processing range is AZ-
Since the value A is large, auto-zero processing is performed without any problem, and therefore the zero is stabilized and displayed as 2 on the display 35.

Therefore, since the zero display is stable immediately after the power is turned on, it is possible to start weighing immediately, which improves practicality.
can.

Then, as time passes, the weighing section 1 and the A/D converter 2
As the operation of the weighing unit gradually stabilizes, the auto-zero processing range becomes smaller from AZ-A to AZ-B, and after a predetermined period of time has elapsed since the power was turned on, the operation of the weighing section] and A/D converter 2 becomes stable. Once stabilized and the drift disappears, the auto-zero processing range becomes the original auto-zero processing range A, Z◆C, and auto-zero processing will be performed in this range thereafter.

Next, other embodiments of the present invention will be described with reference to the drawings.

In FIG. 1, a flag memory is further provided in the RAM 33 as indicated by a dotted line. stop.

The CPU 31, ROM 32, and RAM 33, together with the calculation means, auto-zero processing means, and auto-zero processing range control means, output the auto-zero signal from the A/D converter 2 after a predetermined period of time has elapsed under the control of the auto-zero processing range control child stage. There is an input of count data that exceeds the processing limit. ”: ,t
-To-zero processing range control--The auto-zero processing range switching f stage is configured to switch the auto-zero processing range by the stage to the salmon end A-to zero processing range.

And Figure 4 1. 'As shown in the figure, if a predetermined period of time has passed since the power was turned on, but the FIG. There is.

In other words, the automatic zero processing range continues to be wider than the AZ-C.

When the power switch 5 is turned on and the power is turned on, the CPU 31 performs the control shown in FIG. 5.

The difference from Figure 3 is that when the power is turned on, the Fla
The count data from the A/D converter 2 is taken in after g is cleared to "0".

Also, when both signal TA and signal TB are at L level, FIag
Check whether = 1 or not, and if F tag -1, I
Check whether FI>AZ-C or not, and set Flag-
If o, check whether IFI>AZ-B. (
Auto zero processing range switching means) Furthermore, auto zero processing range switching means)
In zero processing, Fl>AZ-A, IFI>AZ-B
, when IFI>AZ-C, it is determined that weighing has been performed and a display is made based on the calculation results of the A register and the E register. When this display is performed, "1" is set in the Flag memory.

Other than that, it is the same as FIG. 3.

In such a configuration, when the JI amount is performed, the Flag
-1, so if weighing is performed before the predetermined time has elapsed after the power is turned on, the auto-zero processing range after the predetermined time is suitable will be the final auto-zero processing range AZ-C, as in the above embodiment. If measurement is not performed even after a predetermined period of time has elapsed since the power was turned on, the auto-zero processing range will continue to be in the AZ-B state. Therefore, the drift is stabilized even after a predetermined period of time has elapsed since the power was turned on, and even if the drift state continues, the input count data can be more reliably auto-zeroed. Therefore, it is possible to more reliably maintain the zero display state when no load is applied.

In this embodiment as well, the power can be cut off to the old model section 1, A/D converter 2, and calculation/display section 3, and the auto-zero processing range is changed in stages when the power is turned on. The same effects as in the embodiment can be obtained.

In another embodiment, a weight stability detector 37 is provided in the calculation/display section 3 as shown in FIG.
It is configured to detect that the count data from the i-changer 2 becomes stable 1, and to notify the CPU 3 of this fact.

The CPU 31, ROM 32, and RAM 3.3, along with the calculation means, auto-zero processing means, and auto-zero processing range control means, detect the weight stability of the weight stability detector 37, and then the count data from the A/D converter 2 is processed. 7th
As shown by the dotted line in the figure, the forced zero display control means is configured to zero the display data supplied to the display 35 when the value falls below the forced zero range ±Ng, which is set in a range wider than the auto-zero processing range. .

When the power switch 5 is turned on and the power is turned on, the CPU 31 performs the control shown in FIG. 8.

First, clear the Flag to "0" and then import the count data, which is digital data, from the A/D converter 2.
Store in register.

Subsequently, count data is taken in from the A/D converter 2 and stored in the A register.

Then, calculation is performed on the E register input register to obtain Fl.

Next is F! Checks whether "1" is set in the ag memory, and if Flag=0, then the signal TA is set.
is H level, signal TB is H level, or signal T
Check if both A and TB are L level.

If Flag-1, then it is checked whether IFI≦N. (Forced zero display control means) Flag -0
If the signal TA is at H level, then l F l
>Check whether it is AZ-A or not.

If IFI≦AZ-A, it is determined that it is within the auto-zero processing range, and the contents of the A register are stored in the E register. Then, the display data of zero is outputted to the display register 36 and the Flag is cleared to "0". Also, IFI>AZ-A
If so, check whether it is Flag -1.

Further, if the signal TB is at H level at Flag-0, it is subsequently checked whether IFI>AZ-B.

If IFI≦AZφB, it is determined that the auto-zero processing range is reached, and the contents of the A register are stored in the E register. Then, the display data of zero is outputted to the display register 36 and the Flag is cleared to rOJ. Also, IFI>AZ-B
If so, check whether FIag=1.

Furthermore, at Flag -0, both signal TA and signal TB are low.
If it is level, then it is checked whether lpl>AZ-C.

If IFI≦AZ-C, it is determined that it is within the auto-zero processing range, and the contents of the A register are stored in the E register. Then, the display data of zero is outputted to the display register 36 and the Flag is cleared to "0". Also l F l > A
If it is Z-C, it is checked whether it is Flag-1 or not.

If the result of this Flag check is Flag -0, A
The register E register is operated, and display data is created based on the result and output to the display register 36.

Then, it is checked whether the count data is stable based on the signal from the weight stability detector 37, and if it is stable, "1" is set in the flag memory. Moreover, if it is not stable, the flag continues to be -0.

When the display processing is completed, the routine returns to taking in the count data from the A/D converter 2 and storing it in the A register.

Further, in checking whether IFI≦N in Flag-1, if IF1≦N, the contents of the A register are stored in the E register. Then, the display data of zero is outputted to the display register 36 and the Flag is cleared to rOJ. If l F l >N, the routine returns to taking in the count data from the A/D converter 2 and storing it in the A register.

In such a configuration, when weighing is performed and the data is displayed, and the count data becomes stable, the weight stability detector 3
"1" is set in the Flag memory by the stability detection signal from 7.

When the measurement is completed in this state and the no-load state is reached, the count data from the A/D converter 2 becomes small. However, since the frame and other parts that make up the scale are distorted due to the load, it takes time for the distortion to return to its original state. For this reason, the load state of the load cell does not immediately become unloaded, so the A/D converter 2
The count data from will not immediately become count data without a load.

However, even if the count data from the A/D converter 2 is large to some extent, l F l :! When kN is reached, the contents of the A register are stored in the E register and the display data becomes zero. That is, even if the count data from the A/D converter 2 exceeds the auto-zero processing range when the measurement is performed and the measurement is completed at 1, 7, the display immediately becomes zero if IFI≦N.

Obedience/Rite: How many times have you continued 4M? ] In such cases, it takes time to display or return to zero.) There is no problem,
Immediately], you can quickly perform the next step to ensure you return to Xelnia.

In this embodiment as well, the power can be cut off to the weighing section 1, A/D converter 2, and display section 3, and the auto-zero processing interval can be changed in stages when the power is turned on. Since this is carried out in a similar manner, the same effect as in the above embodiment can be obtained.

[Effects of the Invention] As described in detail above, according to the present invention, by turning off the power switch, power is cut off not only to the calculation means and display, but also to the load cell and analog-to-digital converter, thereby reducing consumption. It is possible to provide an electric scale that can save power, and can perform weighing immediately after the power is turned on, improving practicality.

Furthermore, it is possible to provide an electronic scale that can reliably display zero at no load immediately when the weighing movement f1% is continuously carried out.

[Brief explanation of drawings]

Figures 1 to 3 are small scale diagrams of one embodiment of the present invention. Figure 1 is a block diagram, Figure 2 is a diagram showing the auto-zero processing range switching Figures 4 and 5 are flowcharts showing flowcharts for processing the amount of electricity, and Figures 4 and 5 are for other embodiments of the present invention. 6 is a flowchart showing the measurement process by the CPU, FIGS. 6 to 8 show still another embodiment of the present invention, and FIG. 6 is a block diagram.
FIG. 7 is a diagram showing the switching timing of auto-zero processing mode and the forced zero range, and FIG. 8 is a flowchart showing the metering process by the CPU. ]...Weighing section, 2...Analog-digital converter, 31...CPU (central processing unit), 32...RO
M (read-only memory), 33...RA,
M (random access memory), 34... timer, 35... display, 5... power switch, 6... power supply section. Applicant's agent Patent attorney Takehiko Suzue r, ri 4 N

Claims (3)

[Claims] (1) A weighing section that has a load cell that outputs an electrical signal corresponding to the load, an analog-to-digital converter that converts the analog electrical signal from this weighing section into digital count data, and count data from this converter. a calculation means for generating weight display data by processing the calculation means, an auto-zero processing means for forcibly zeroing the display data when the count data input to the calculation means is within a preset auto-zero processing range, and from the calculation means. In an electronic scale comprising a display that displays display data, the weighing section,
The auto-zero processing range of the power switch that turns on and off the power to the analog-to-digital converter, calculation means, and display, and the auto-zero processing means is set to a large range immediately after the power switch is turned on, and the range increases over time. 1. An electronic scale comprising auto-zero processing range control means for reducing the value of the auto-zero processing range to a predetermined final auto-zero processing range after a predetermined period of time has elapsed. (2) A weighing section that has a load cell that outputs an electrical signal corresponding to the load, an analog-to-digital converter that converts the analog electrical signal from this weighing section into digital count data, and count data from this converter. a calculation means for generating weight display data by processing the calculation means, an auto-zero processing means for forcibly zeroing the display data when the count data input to the calculation means is within a preset auto-zero processing range, and from the calculation means. In an electronic scale comprising a display that displays display data, the weighing section,
The auto-zero processing range of the power switch that turns on and off the power to the analog-to-digital converter, calculation means, and display, and the auto-zero processing means is set to a large range immediately after the power switch is turned on, and the range increases over time. an auto-zero processing range control means that reduces the auto-zero processing range and controls the auto-zero processing range to a slightly wider range than a preset final auto-zero processing range after a predetermined period of time has elapsed; and an auto-zero processing range switching means for switching the auto-zero processing range by the auto-zero processing range control means to a final auto-zero processing range when count data exceeding the auto-zero processing range is input from the analog-to-digital converter. Electronic scale. (3) A weighing section that has a load cell that outputs an electrical signal corresponding to the load, an analog-to-digital converter that converts the analog electrical signal from this weighing section into digital count data, and count data from this converter. a calculation means for generating weight display data by processing the calculation means, an auto-zero processing means for forcibly zeroing the display data when the count data input to the calculation means is within a preset auto-zero processing range, and from the calculation means. In an electronic scale comprising a display that displays display data, the weighing section,
The auto-zero processing range of the power switch that turns on and off the power to the analog-to-digital converter, calculation means, and display, and the auto-zero processing means is set to a large range immediately after the power switch is turned on, and the range increases over time. an auto-zero processing range control means that reduces the auto-zero processing range and controls the auto-zero processing range to a preset final auto-zero processing range after a predetermined time elapses, and detects weight stability when count data exceeding the auto-zero processing range is input from the analog-to-digital converter. a weight stability detector; and after the weight stability detector detects weight stability, if the count data from the analog-to-digital converter falls below a forced zero range that is set in a range wider than the auto-zero processing range, the calculation means An electronic scale characterized by comprising forced zero display control means for setting display data supplied to the display to zero.