CN202420661U - Portable high-precision electronic scale - Google Patents

Abstract

The utility model provides a high-precision portable electronic scale which comprises a capacitive sensing module, a high-stability reference capacitive module, a multiway switch module, a main control module, a display module and a key module. The utility model is characterized in that the main control module is respectively connected with the multiway switch module, display module and the key module; and the multiway switch module is also connected with the capacitive sensing module and high-stability reference capacitive module. When measuring the weight of an object, the capacitance value measured by the capacitive sensing module is subjected to capacitive frequency conversion to generate a reference frequency signal by the high-stability reference capacitive module; the reference frequency signal is subjected to error elimination and transmitted to the main control module through the multiway switch module; the main control module computes the measured value and carries out logical processing; and after the processed result is displayed by the display module, the key module can set related parameters.

Description

The portable high-accuracy electronic scales

Technical field

The utility model relates to a kind of electronic scale, especially the high-accuracy portable electronic scale.

Background technology

At present, the use of desk-top electronic scales in commerce and trade is quite general, and bigger limitation volume is big, cost is high, need the AC power supply, carry inconvenience, application places is restricted but exist.Existing portable balance is steelyard or realizes the spring balance that measures with spring, stretcher strain that what the resident used is steelyard basically.Spring pan scale manufacture process requirement is higher; The fatigue problem of spring can't thoroughly solve, in case surpass the spring limit, spring balance will produce very mistake; So that damage; Having influence on the accuracy and the reliability of weighing, is a kind of temporary transient substitute, also is put into the ranks of cancellation gradually.

Summary of the invention

In order to overcome the above problems, it is the main control module that the utility model adopts single-chip microcomputer, has adopted the high stable reference capacitance to calibrate, and has safe and reliable, quick direct-reading, easy to carry, precision advantages of higher.

The utility model provides a kind of high-accuracy portable electronic scale; Comprise capacitance sensing module, high stable reference capacitance module, multi-way switch module, main control module, display module, key-press module; It is characterized in that: the main control module is connected with multi-way switch module, display module, key-press module respectively, and the multi-way switch module also is connected with capacitance sensing module, high stable reference capacitance module.When Measuring Object weight, the capacitance that the capacitance sensing module measures is through the electric capacity frequency inverted, and employing high stable reference capacitance module generates reference frequency signal; Eliminate error; Be sent to the main control module through the multi-way switch module, the main control module is calculated measured value, after the logical process; Show that through display module key-press module can be provided with correlation parameter.

The beneficial effect of the utility model is, the electronic scales volume is little, accurate measurement, easy to carry, precision is high, integrates quality weighing function and calculation of price function, can satisfy the user demand of commerce and trade and resident family, has higher utility.

Description of drawings

Fig. 1 is the theory diagram of the utility model.

Embodiment

In Fig. 1; The high-accuracy portable electronic scale; Comprise capacitance sensing module 1, high stable reference capacitance module 2, multi-way switch module 3, main control module 4, display module 5, key-press module 6; It is characterized in that: main control module 4 is connected with multi-way switch module 3, display module 5, key-press module 6 respectively, and multi-way switch module 3 also is connected with capacitance sensing module 1, high stable reference capacitance module 2.When Measuring Object weight, the capacitance that capacitance sensing module 1 measures is through the electric capacity frequency inverted, and employing high stable reference capacitance module 2 generates reference frequency signals; Eliminate error; Be sent to main control module 4 through multi-way switch module 3, main control module 4 is calculated measured value, after the logical process; Show that through display module 5 key-press module 6 can be provided with correlation parameter.

Capacitance sensing module 1 adopts pole-changing apart from the formula capacitive transducer; It is made up of the parallel plate electrode of a pair of distance variable, and two plates link to each other with flexible member, when when a portable plate applies pulling force; The two-plate distance changes; Thereby changed the electric capacity of plate condenser, after the electric capacity frequency inverted, the circuit output frequency is directly proportional with electric capacity.High stable reference capacitance module 2 is to be made up of cref electric capacity and ICM7556 timer, generates reference frequency signal, eliminates systematic error, realizes high-acruracy survey.What multi-way switch module 3 adopted is that MAX325 is the accurate single supply SPST analog switch that MAXIM company produces, and it is made up of an open type switch and a closed type switch, has characteristics such as low-power consumption, low on-resistance.These chip two control ends all connect the RB3 pin of main control module 4; The selection of system's two-way frequency signal input channel is by 4 controls of main control module; What main control module 4 adopted is the PIC16F628 single-chip microcomputer of Microchip company, has execution speed height, low in energy consumption, advantages of small volume, WV is low, driving force is strong, superior function such as wide in variety, and operating voltage range is 3.0v ~ 5.5v; Clock frequency is DC ~ 20MHZ; Inside has 1kX14 (position) sheet internal program storer, the general RAM of 224 bytes, 128 byte EEPROM; 15 two-way I/O lines and 10 interrupt sources, and have one 16 bit timing device/counter (TMR1) and one 8 bit timing device/counter (TMRO).Display module 5 adopts 44780 LCD driven; HD44780 (KS0062) is the extensive dot matrix lcd controller made from the Low-Power CMOS technology, links to each other with the 4bit/8bit microprocessor, and it can make dot matrix LCD show the information that capital and small letter English alphabet, numbers and symbols etc. are abundant; There is stronger versatility to use simultaneously; Easy to use, the user can just can form a perfect lattice LCD system with few components, and what key-press module 6 adopted is 4 * 4 matrix keyboards; One has 16 keys, is respectively numerical key 0 ~ 9 and function key A ~ F.

Claims (1)

1. the utility model provides a kind of high-accuracy portable electronic scale; Comprise capacitance sensing module (1), high stable reference capacitance module (2), multi-way switch module (3), main control module (4), display module (5), key-press module (6); It is characterized in that: main control module (4) is connected with multi-way switch module (3), display module (5), key-press module (6) respectively, and multi-way switch module (3) also is connected with capacitance sensing module (1), high stable reference capacitance module (2).