CN206300712U - A four-point weighing electronic scale circuit - Google Patents

Abstract

The utility model discloses a four-point type electronic scale circuit that weighs, including resistance-type pressure sensor S1, pressure sensor S2, pressure sensor S3 and pressure sensor S4, pressure sensor S1 and pressure sensor S2 'S the parallelly connected first electric bridge that forms in both ends, pressure sensor S3 and pressure sensor S4' S the parallelly connected second electric bridge that forms in both ends, a termination power positive pole VDD behind first electric bridge and the series connection of second electric bridge, another termination power negative pole GND, two resistances that utilize resistance-type pressure sensor self constitute two electric bridges, add the measured value of two electric bridges and obtain four pressure sensor whole outputs, also can measure single pressure sensor, operating current is the fourth of the parallelly connected electric bridge among the prior art only, make the life greatly increased of battery.

Description

A four-point weighing electronic scale circuit

technical field

The utility model relates to a weighing apparatus, in particular to a four-point weighing electronic scale.

Background technique

The half-bridge four-point weighing using batteries is to set a pressure sensor at each of the four corners of the electronic scale, and calculate the weight through the Wheatstone balanced bridge method. The current four-point weighing electronic scale circuit is shown in Figure 1. Its four pressure sensors are connected in parallel between the positive and negative poles of the power supply, and the working current is 1=2V/R. On the sensor, this leads to a large operating current of the system and a short service life of the battery.

Contents of the invention

In order to overcome the deficiencies of the prior art, the utility model provides a four-point weighing electronic scale circuit with small working current.

The technical scheme that the utility model solves its technical problem adopts is:

A four-point weighing electronic scale circuit, comprising a resistive pressure sensor S1, a pressure sensor S2, a pressure sensor S3 and a pressure sensor S4, the two ends of the pressure sensor S1 and the pressure sensor S2 are connected in parallel to form a first electric bridge, The two ends of the pressure sensor S3 and the pressure sensor S4 are connected in parallel to form a second electric bridge. After the first electric bridge and the second electric bridge are connected in series, one end thereof is connected to the positive pole of the power supply VDD, and the other end is connected to the negative pole of the power supply GND.

The beneficial effects of the utility model are: the utility model utilizes the two resistances of the resistive pressure sensor itself to form two electric bridges, and the measured values of the two electric bridges are added to obtain the entire output of the four pressure sensors, and it can also be used for a single pressure sensor. The sensor is used for measurement, and the working current is only a quarter of that of the parallel bridge in the prior art, so that the service life of the battery is greatly increased.

Description of drawings

Below in conjunction with accompanying drawing and embodiment the utility model is further described.

Fig. 1 is a four-point weighing electronic scale circuit in the prior art;

Fig. 2 is the four-point weighing electronic scale circuit of the utility model.

detailed description

Referring to Fig. 2, a four-point weighing electronic scale circuit includes a resistive pressure sensor S1, a pressure sensor S2, a pressure sensor S3 and a pressure sensor S4, and the two ends of the pressure sensor S1 and the pressure sensor S2 are connected in parallel to form a first An electric bridge, the two ends of the pressure sensor S3 and the pressure sensor S4 are connected in parallel to form a second electric bridge, and after the first electric bridge and the second electric bridge are connected in series, one end is connected to the positive pole of the power supply VDD, and the other end is connected to the negative pole of the power supply GND.

When the increment of one of the resistances in the same pressure sensor is ΔR, the increment of the other resistance is -ΔR, that is, the resistance value of a single pressure sensor is constant, and the voltage change of the weight will not affect the voltage and current. The two resistances of the resistive pressure sensor are used to form two bridges, and the measured values of the two bridges are added to obtain the entire output of the four pressure sensors. It is also possible to measure a single pressure sensor, and the working current is I=V/ 2R, only a quarter of the parallel bridge in the prior art, so that the service life of the battery is greatly increased.

Claims (1)

1. a kind of pressure sensor S1 of four-point weighing electronic scale circuit, including resistance-type, pressure sensor S2, pressure sensing Device S3 and pressure sensor S4, it is characterised in that the two ends of the pressure sensor S1 and pressure sensor S2 are in parallel to form first Electric bridge, the two ends of the pressure sensor S3 and pressure sensor S4 are in parallel to form the second electric bridge, first electric bridge and second Electric bridge series connection latter termination power positive pole VDD, another termination power cathode GND.