JPS6230368B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an electronic scale using a load cell.

For example, in the UK, scales are used that use the pound-ounce system (1 pound is 16 ounces), but if this scale could be converted to a scale that uses the kilogram system, it would be extremely effective as a scale. I can do it. By the way, considering that 1 pound is 16 ounces and 1 ounce is approximately 30 g, converting the pound/ounce system to the kilogram system would be extremely troublesome if processed analogously.
It becomes difficult to convert.

This invention has been made in view of the above points, and it is possible to easily convert the measurement unit from the pound-ounce system to the kilogram system by a simple operation, and it is possible to easily convert the measurement unit from the pound-ounce system to the kilogram system, and furthermore, there is a possibility that the resolution of the minimum scale value may be reduced. The purpose of the present invention is to provide an electronic scale with no leakage.

For example, pounds with the minimum scale value of 1/8 ounce.
If you manufacture an ounce scale and set 1/8 ounce to 10 counts, a 22 pound scale will yield 28,160 counts. The minimum scale value of this scale is 10 counts 5g
If you consider converting to a kilogram scale with a weight of 10Kg, 10Kg will be 20,000 counts, but in reality it is adjusted to 28,160 counts for 22 pounds, so 10Kg will be 28,219 counts. This gives us a scale of 22 pounds - 1/8 ounce (10 counts).
When using a Kg-5g (10 count) scale, the number of weighing counts read is 20000/28219 (≒
After multiplying by the conversion constant (0.708742), the weight data can be calculated using 10 counts of 5 g.

This invention has been made based on the results of such investigation and is intended to accomplish the above-mentioned object.

Embodiments of the present invention will be described below with reference to the drawings.

Figure 1 is a block diagram showing the circuit configuration, 1 is a load cell that outputs a voltage signal according to load 2, 3 is a load cell that outputs a voltage signal according to load 2;
is an analog/digital (A/
D) Converter, 4 is a numeric keypad used for unit price setting, and 5 is a status switch for specifying various states. The status switch 5 is particularly provided with a conversion switch 5a for switching the measurement unit system from the pound-ounce system to the kilogram system. 6 is a digital display device equipped with weight, unit price, and price indicators, and 7 is various lamps such as a zero point and a tare.
8 outputs the unit price set by the numeric keypad 4 to the display device 6, also reads the pulse number signal from the A/D converter 3, and based on the pulse number signal, the contents of the switches 5a and 5b are determined. Calculate weight data in pound/ounce system or kilogram system,
The weight data is output to the display device 6, and the price is calculated from the unit price and weight.
This microcomputer 8 is a microcomputer that performs various processing such as outputting data to the computer.The microcomputer 8 contains a ROM (read-only memory) that stores fixed data such as programs, and stores data that is being processed.
Memory such as RAM (read only memory) is provided.

As shown in FIG.
It consists of 16 256 words. The main memory configuration in this RAM can be described with each word represented by M[X, Y] and each bit represented by <>.
Five words [0,0] to M[0,4] form a five-digit weight register 9, and M[2,F], M[2,
E], M[2, D], M[2, C], M[2, B]
FR ₁₂ , FR ₁₁ , FR ₁₀ , FR ₉ , FR ₈ in one word each
form each register 10, 11, 12, 13, 14, and convert F with 1 bit of M[6,0]<3>.
(Flag) 15 is formed. Also M [7,
0] to M[7,4] form a 5-digit ADC register 16, and M[8,0] to M[8,
5], M[9,0] to M[9,5], M[A,0]
~M[A,5], M[B,0] to M[B,5] form the conversion register 17, and M[C,0]
~M[C,A],M[D,0]~M[D,A],M
[E,0]~M[E,A], M[F,0]~M
[F, A] form a conversion calculation register 18.

Figure 3 shows a routine that rounds the count number in the weight register 9 into pound-ounce weight data, and this routine converts F=0.
10 counts are rounded to 1/8 ounce. This routine first
Clear FR ₈ to FR ₁₂ , then check whether the count number of weight register 9 is 12800 or more,
If it is 12,800 or more, add 1 to FR ₁₂ and subtract 12,800 from weight register 9. This process is repeated until the count number in the weight register 9 becomes smaller than 12,800. When the count number of the weight register 9 becomes less than 12800, it is next checked whether it is 1280 or more. If it is 1280 or more, add 1 to FR ₁₁ and subtract 1280 from weight register 9.
This process is repeated until the count number of the weight register 9 becomes smaller than 1280. When the count number of weight register 9 becomes less than 1280,
Check whether it is 800 or more. If it is over 800, add 1 to FR ₁₀ and read 800 from weight register 9.
Subtract. This process is repeated until the count number in the weight register 9 becomes less than 800.
When the count number of the weight register 9 becomes less than 800, it is next checked whether it is 80 or more. and
If it is 80 or more, add 1 to FR ₉ and enter weight register 9.
Subtract 80 from. This process is repeated until the count number in the weight register 9 becomes less than 80. When the count number of the weight register 9 becomes less than 80, the count number of the weight register 9 becomes smaller than 80.
Store the 10th digit in FR ₈ . After the weight indicator of the display device 6 is suppressed to zero, the contents of FR ₁₂ to FR ₈ are displayed on the weight indicator. In this case, the lowest digit on the weight display indicates 1/8 ounce, and as the contents of FR ₈ change to 0, 1, 2, 3, 4, 5, 6, and 7, the display goes off and 1/8 , 1/4, 3/8, 1/2, 5/8,
It is starting to change from 3/4 to 7/8.

For example, when 15000 counts are stored in weight register 9, FR ₁₂ = 1, FR ₁₁ = 1, FR ₁₀
= 1, FR ₉ = 1, FR ₈ = 4, so in this case
It would read 11 pounds 11 1/2 ounces.

FIG. 4 is a flow chart showing the routine that the microcomputer 8 performs based on the settings of the conversion switch 5a of the status switch 5. When the power is turned on, the microcomputer 8 first clears the RAM, and then clears each switch of the status switch 5. Read the configuration status of. In this reading, when the conversion switch 5a is ON, conversion F=1, and when it is OFF, conversion F=0. For example, the conversion switch 5a
When weighing starts when conversion F=1 with ON, A/D
A pulse signal corresponding to the load is output to the converter 3, and the microcomputer 8 receives this pulse signal.
Read into ADC register 16. and the transformation F=1
It is determined that the conversion constants 708 and 742 are set in the conversion register 17. This is the conversion constant obtained when converting from a scale that weighs 22 pounds and has a minimum scale value of 1/8 ounce (10 counts) to a scale that weighs 10 kg and has a minimum scale value of 5 g (10 counts). continue
The count number of the ADC register 16 is multiplied by the constant of the conversion register 17, and the result is stored in the conversion calculation register 18. Then, the sixth digit of the conversion calculation register 18 is rounded off, and the upper five digits of the register 18 are transferred to the weight register 9, and the weight is rounded to 10 counts of 5 g using the unit price x weight routine. For example, due to a weighing operation, the A/D converter 3
If the number of counts read into the ADC register 16 is 17200 counts, then 12190362400 (17200×708742) will be stored in the conversion calculation register 18, and 12190 counts will be stored in the weight register. And if we round up this 12190 to 10 counts of 5g, it becomes 6095Kg. In this way, 6095 kg is displayed on the weight display of the display device 6.

The above describes a scale that converts a 22 pound - 1/8 ounce (10 count) scale into a 10 kg - 5 g (10 count) scale, but it is not limited to this. For example, 6 kg - 2 g (10 count). ) can also be converted to a scale. In this case 2g
At 10 counts, 6Kg needs to be 30,000 counts, but it is actually adjusted to 28,160 counts for 22 pounds, so 6Kg is 16,931 counts. Therefore, it is necessary to convert 16931 counts at 6Kg to 30000 counts. From this, the scale of 22 pounds - 1/8 ounce (10 count) is 6Kg - 2g.
(10 counts), it is sufficient to multiply the read weighing count number by a conversion constant of 30000/16931≒177190, and then round the weight to 10 counts, 2 g. For example, by metering operation A/D
If the count read from the converter 3 to the ADC register 16 is 12,300 counts, the conversion calculation register 18 contains 12,300 x 177,190.
2179437000 is stored and weight register 9 is 21794
The count number will be stored. and this
Rounding up 21794 counts to 10 counts and 2g gives 4358Kg. In this way, 4358 kg is displayed on the weight display of the display device 6.

In this way, when the weight is 22 pounds, the minimum scale value is 1/8
Easily convert a scale with 10 counts in ounces to a scale with a weight of 10 kg and a minimum scale value of 5 g and a 10 count scale, or a scale with a weight of 6 kg and a minimum scale value of 2 g and 10 counts by setting a conversion constant. be able to. Moreover, switching of this scale can be easily performed by operating a status switch. In addition, the minimum scale value can be set to 10 counts for scales with a weighing capacity of 22 pounds, 10 kg, and 6 kg, so there is no risk of deterioration in resolution.

As detailed above, according to this invention, the pound
A kilogram system scale in which the minimum scale value is set to be equal to the minimum scale value in the pound-ounce system by operating a kilogram system conversion instruction means, in an electronic scale that is set in the ounce system and displays weight digitally. You can convert the count number of the weight at that time and the weight in the kilogram system to pounds and kilograms.
Since the conversion constant is the ratio of the number of counts obtained by converting to the ounce system, it is possible to easily convert a scale with units of measurement in pounds and ounces to a scale in the kilogram system with a simple operation. It is possible to provide an electronic scale without the risk of deterioration in the resolution of the minimum scale value.

[Brief explanation of the drawing]

The figures show an embodiment of the present invention. Fig. 1 is a block diagram, Fig. 2 is a diagram showing the main memory configuration of RAM, Fig. 3 is a flowchart showing the weight rounding process of pound-ounce system, and Fig. Figure 4 is a flowchart showing the conversion process when converting a 22 pound - 1/8 ounce (10 count) scale to a 10 kg - 5 g (10 count) scale. 1... Load cell, 3... A/D converter, 5a... Conversion switch, 6... Display device, 8... Microcomputer, 15... Conversion F, 16... ADC register, 1
7...Conversion register.

Claims (1)

[Claims] 1. A load cell that outputs the load amount as a voltage signal, an analog-to-digital converter that converts this load cell output into a pulse number signal, reads the output of this converter, and uses the count number as the standard for the minimum scale value set in the pound-ounce system. In an electronic scale comprising a means for calculating weight data and a display for digitally displaying the weight data calculated by the calculation means, a kilogram system conversion instruction means and a minimum scale value set in the kilogram system are used. Set the count number to be the same as the count number for the minimum scale value in the above-mentioned pound-ounce system to determine the count number for weighing in the kilogram system,
Conversion to the kilogram system is instructed by means for setting the ratio of the count number and the count number obtained by converting the weighing weight in the kilogram system to the pound-ounce system as a conversion constant, and the above-mentioned kilogram system conversion instruction means. means for converting the output of the analog-to-digital converter based on the conversion constant of the conversion constant setting means and further calculating weight data based on the count number with respect to the minimum scale value set in the kilogram system, An electronic scale characterized in that the weight data calculated by the means is displayed on the display.