CN2506994Y

CN2506994Y - Hand carried electronic balance with price caculation

Info

Publication number: CN2506994Y
Application number: CN 01267659
Authority: CN
Inventors: 王凤才
Original assignee: Individual
Current assignee: Individual
Priority date: 2001-10-16
Filing date: 2001-10-16
Publication date: 2002-08-21
Anticipated expiration: 2011-10-16

Abstract

The utility model provides a battery supply portable pricing electronic scale, comprising a weighting sensor, an amplifier, an A/D convertor, an LCD, a SCM and so on. A weighting voltage detecting signal output by the weighting sensor is amplified by the amplifier, and is converted by the A/D, and is computing processed by the SCM, and is displayed by the LCD. The option button on the panel can display weight, input unit price, and computer sum of money as required and can weight and compute sum of money for the weighted object conveniently.

Description

Portable valuation electronic scale

The utility model is the portable valuation electronic scale that the A/D converter that adopts LOAD CELLS, high precision linear amplifier, be made of the voltage/frequency transducer, single-chip microcomputer, segment code type LCDs etc. are formed.The two kinds of functions of weighing, valuate can be weighed and calculate the amount of money by unit price object.

The journey electronic scale mostly is desk-top in a small amount at present, is generally multi-screen, segment code type charactron double-sided display, can weigh and calculate the amount of money, shows weight with a screen, and a screen shows unit price, and a screen shows the amount of money.This electronic scale technical feature is fine, the resolution height, and error is very little, but its shortcoming one is the price height, the 2nd, fixedly lay, and the 3rd, use AC power.This uses very inconvenient to flow pedlar and non-stationary applica-tions, because price is more higher hucksters and general family expenses also are difficult for accepting.Beijing people from Tsing-Hua University is developed the portable domestic electronic of a OCS series and claimed that though fine in form, price is not high yet, and is desirable not enough on actual performance.The one, accuracy class is on the low side, and the accuracy class of general measure utensil should be better than 1.5 grades at present, and this product is 4 grades.The 2nd, resolution is on the low side to be 10 grams, and minimum is weighed as 50 grams, the unification liang, and weight just can't weighing less than the object of a liang, and this is also very inconvenient.

Main task of the present utility model is to form the use of can flowing, and need not fixedly lay, and without AC power, the valuation function is arranged again, and accuracy class is better than 1.0 grades, and resolution is 2 grams, and price is hanged down portable easily again weighing instrument.

The portable valuation electronic scale of the utility model is by dry cell power supply, in housing 3, establish a metallic support negative 14, outside housing, be connected a handle 2 with negative, with the handle vertical axis is benchmark, be installed on LOAD CELLS 13 on the negative exactly, below LOAD CELLS, adorn a hook 11 along this axis, promptly the weighed center of gravity line of thing of this axis; Mounting circuit boards 15 between the front side of negative and the housing front panel, SCM peripheral and the accessory circuits such as A/D converter single-chip microcomputer, high precision linear amplifier 16 being installed on the circuit board, being constituted by voltage/frequency transducer 17; The rear side of base plate is installed battery folder 12; Segment code type LCDs 1, power switch button 4, reset button 6 are installed on the front panel of housing; Mode button 5 is set, joins with the interruption 1 of single-chip microcomputer by 23 by de-twitter circuit 31; Unit price load button 8 is set, joins with the interruption 2 of single-chip microcomputer by 25 by de-twitter circuit 31; Carry button 7 is set, join by the input end of de-twitter circuit 31 with two AND circuit of circuit 32, the output terminal of two AND circuit is connected to the input end and the clock end of two triggers of circuit 34 respectively, the output terminal of two triggers by triple gate buffer circuits 35 by 27,28 and P1.1, the P1.2 of single-chip microcomputer join; Radix point button 10 is set, joins by de-twitter circuit 31 and the input end and the clock end of two triggers of circuit 33, one of two output terminal of trigger 36 be high level another be low level, be connected to the input end of two AND circuit of circuit 32 respectively; The output terminal of trigger 37 by triple gate buffer circuits 35 by 29 P1.3 that are connected to single-chip microcomputer; The P1.4 of single-chip microcomputer is connected to 30, is connected to the set end of the trigger of trigger 37 and circuit 34 by triple gate buffer circuits 35; Data button 9 is set, joins with the counter 2 of single-chip microcomputer by 24 by de-twitter circuit 31; Click mode button 5 when being over and just show the weight of weighing just now when weighing, just show unit price during again by one time, then click unit price load button 8 if will import unit price, this moment, display screen showed 0.00, at this moment can be by the data button on the panel 9, carry button 7 and radix point button 10 input unit prices, if unit price is suitable just to show the amount of money that is calculated by weight and unit price by a mode button 5 again, can easily finish and weigh, import unit price and calculate the amount of money.

The utility model is described in further detail below in conjunction with the drawings and specific embodiments:

Fig. 1 is the front panel figure of portable valuation electronic scale

Fig. 2 is a portable valuation electronic scale schematic internal view (backsight)

Fig. 3 is LOAD CELLS, the high precision linear amplifier of portable valuation electronic scale, the local circuit schematic diagram of electric voltage/frequency converter

Fig. 4 is a portable valuation electronic scale unit price importation local circuit schematic diagram

Sequence number 1 among Fig. 1 is the segment code type LCDs, selects 4 half here for use, and maximum demonstration number is 19999, can accomplish that maximum range is 10 kilograms or 20 kilograms, shows 1 during outrange, and display resolution is gram.Sequence number 2 is handles, and sequence number 3 is housings, and housing can also can be used plastics with metal, but if preferably circuit board is done shielding during with plastics, in order to avoid disturb other electronic equipment.Sequence number 4 is power switch buttons, and sequence number 6 is reset button, just enters the state of weighing after resetting, and the tracking of returning to zero.Sequence number 5 is mode buttons, clicks mode button when being over when weighing and just shows the weight of weighing just now, just shows unit price during again by one time, if unit price correctly just shows the amount of money that is calculated by weight and unit price by a mode button again.Sequence number 8 is unit price load buttons, if will import unit price then clicks the unit price load button, this moment, display screen showed 0.00, and the position flicker before the radix point, at this moment can be by buttons such as the data on the panel, carry and radix point input unit price, the maximum input level of unit price is 99.99.Sequence number 7 is carry buttons, in the time will importing second-order digit, clicks this button, then to one of reach, then moves one backward behind the radix point before the radix point.Sequence number 10 is the radix point button, when the integer-bit input is over, by just importing decimal behind this button.Sequence number 9 is data button, by once making numeral to be imported add 1.After finishing, input, just returns with arriving demonstration weight state again by a unit price load button.Sequence number 11 is hooks.

Sequence number 12 among Fig. 2 is battery folder, and sequence number 13 is LOAD CELLS, must be that benchmark is accurately installed with the vertical axis of handle, avoids producing weighting error.Sequence number 14 is metal base plates, and negative will have certain intensity, all parts be installed on the negative and and shell fix.Sequence number 15 is circuit boards.

Fig. 3 is the partial circuit diagram of LOAD CELLS, high precision linear amplifier, voltage/frequency transducer, and R1--R4 is the bridge resistance, of LOAD CELLS, and W1 is the balance adjustment potentiometer.Also can select the sensor of other pattern for use, but sensitivity, the linearity, stability etc. to be got well necessarily.Circuit 16 is amplifiers, the 17th, and electric voltage/frequency converter, the quality of this part circuit is most important, directly influences the precision and the accuracy of weighing, must select the device of precision height, good stability for use.20, the 21st, positive and negative power supply must be used high-precision regulated power supply, and the quality of power supply directly influences the important indicators such as performance, precision, stability of circuit.Sensitivity, accuracy class, resolution, stability etc. will be guaranteed by this part circuit all.The global error of controlling LOAD CELLS and linear amplifier is in 0.5%, and electric voltage/frequency converter cooperates the A/D converter that constitutes more than 14 with single-chip microcomputer, just can realize that it is the per mille kilogram that accuracy class is better than 1.0 grades and resolution.The 22nd, the output terminal of electric voltage/frequency converter, join with the counter 1 of single-chip microcomputer, produce the detection electric signal by LOAD CELLS 13 symmetrical weight bodies when weighing, be amplified to certain voltage value through high precision linear amplifier 16 again, give voltage/frequency transducer 17 then and carry out the voltage/frequency conversion, just obtain the pulse of certain frequency at its output terminal 22, within a certain period of time to this step-by-step counting, the count value that obtains is a gravimetric value after being read and handled by single-chip microcomputer by the counter 1 of single-chip microcomputer.Here cooperate with single-chip microcomputer with electric voltage/frequency converter and constitute A/D converter, reason is to weigh 10 kilograms the time, will be with one 14 A/D converter, such A/D converter price is very expensive, can constitute a A/D converter the highest 16 easily and cooperate with single-chip microcomputer with electric voltage/frequency converter, can realize that maximum weighs 65 kilograms, and price only be 14 A/D converters 1/4th to sixth, and resolution is the per mille kilogram.

Circuit 31 is Schmidt triggers among Fig. 4, here as de-twitter circuit, suitablely just can play the effect of trembling of well going if the time constant of resistance, electric capacity is selected.When mode button 5 is pressed, 23 is electronegative potential, the single-chip microcomputer response is interrupted, enter interrupt service routine, a register can be set in interrupt service routine, and each interruption all makes register add 1, the

value

1,2,3 in the register corresponding respectively demonstration weight, show unit price, calculating and show the amount of money, single-chip microcomputer detects this register and goes to carry out corresponding program at the program entry place, can show content corresponding when mode button 5 is pressed.When the value in the register is 3, then return during again by one time and this register of zero clearing.Unit price load button 8 enters when pressing and interrupts 2 unit prices input service routine, can carry out the unit price input, at this moment display screen shows 0.00, and the position flicker before the radix point, data button 9 is whenever by next time, the counter 2 of single-chip microcomputer adds 1 and read demonstration by single-chip microcomputer, be added to 9 o'clock again by once just with counter 2 zero clearings, it is unit price numbers of input that single-chip microcomputer is read the data in the counter.If in the time of will importing second-order digit, click carry button 7, at this moment circuit 32 and two input ends door 38 all are noble potentials, trigger 40 upsets, and output terminal 27 becomes electronegative potential, 27 join with the P1.1 of single-chip microcomputer, single-chip microcomputer inquires P1.1 when being electronegative potential, just goes the program of one of combine digital reach, with the numeral just imported to one of reach, and at this moment the still flicker of a position before the radix point can import second-order digit.Click radix point button 10 when importing radix point, at this moment trigger 36,37 overturns simultaneously, makes 29 to become electronegative potential after 37 upsets, and 29 are connected to the P1.3 of single-chip microcomputer, and single-chip microcomputer inquires P1.3 when being electronegative potential, just goes to carry out input radix point program.Later input digit again is first behind the radix point, in the time of will importing the back one-bit digital again, click carry button 7 again, at this moment since trigger 36 overturn, with two input ends of door 39 all be noble potential, trigger 41 upsets, output terminal 28 becomes electronegative potential, 28 join with the P1.2 of single-chip microcomputer, and single-chip microcomputer inquires P1.2 when being electronegative potential, just go to move after the combine digital one program.Input clicks unit price load button constipation bundle loading routine again and turns back to and shows the weight state when being over.So just, can finish easily and weigh, import unit price and calculate the amount of money.

Claims

1. portable valuation electronic scale by dry cell power supply, in housing 3, establish a metallic support negative 14, outside housing, be connected a handle 2 with negative, with the handle vertical axis is benchmark, be installed on LOAD CELLS 13 on the negative exactly, below LOAD CELLS, adorn a hook 11 along this axis, promptly the weighed center of gravity line of thing of this axis; Mounting circuit boards 15 between the front side of negative and the housing front panel, SCM peripheral and the accessory circuits such as A/D converter single-chip microcomputer, high precision linear amplifier 16 being installed on the circuit board, being constituted by voltage/frequency transducer 17; The rear side of base plate is installed battery folder 12; Segment code type LCDs 1, button 4, button 6 are installed on the front panel of housing; It is characterized in that: (1) establishes button 5, joins with the interruption 1 of single-chip microcomputer by 23 by circuit 31; (2) button 8 is set, joins with the interruption 2 of single-chip microcomputer by 25 by circuit 31; (3) button 7 is set, join by the input end of circuit 31 with two AND circuit of circuit 32, the output terminal of two AND circuit is connected to the input end and the clock end of two triggers of circuit 34 respectively, the output terminal of two triggers by triple gate buffer circuits 35 by 27,28 and P1.1, the P1.2 of single-chip microcomputer join; (4) button 10 is set, join by circuit 31 and the input end and the clock end of two triggers 36,37 of circuit 33, one of two output terminal of trigger 36 be high level another be low level, be connected to the input end of two AND circuit 38,39 of circuit 32 respectively, the output terminal of trigger 37 by triple gate buffer circuits 35 by 29 P1.3 that are connected to single-chip microcomputer, the P1.4 of single-chip microcomputer is connected to 30, is connected to the set end of trigger 37 and trigger 40,41 by triple gate buffer circuits 35; (5) button 9 is set, joins with the counter 2 of single-chip microcomputer by 24 by circuit 31.