Thermometer for stepper motor drive finger

Abstract

The invention relates to a thermometer of a pointer driven by a stepper motor, and the thermometer comprises a monolithic processor, a stabilized voltage power supply connected with an automobile battery, a thermal resistance sensor used for collecting the temperature of the automobile engine oil, a signal processing amplifying circuit electrically connected between the monolithic processor and the thermal resistance sensor, a motor drive circuit which enables the output signals processed by the monolithic processor to be amplified and then outputs the output signals to the stepper motor, and a linear conversion circuit, wherein, the motor drive circuit is electrically connected between the monolithic processor and the stepper motor; the linear conversion circuit is electrically connected with the SPI output interface of the monolithic processor; the 11 foot and the 12 foot of the monolithic processor are respectively welded with two interfaces used for full scale adjustment or zero point adjustment, and arranged on an eclectic circuit board; the stabilized voltage power supply is respectively connected with the monolithic processor and the signal processing amplifying circuit through an output branch circuit. The thermometer of the invention has a good overall linearity, the electric current output of the instrument is stable, the thermometer has a data remote transmission function, and the adjustment method of the full scale as well as zero point is simple.

Description

technical field [0001] The invention relates to an automobile thermometer, in particular to a thermometer for a pointer driven by a stepping motor for detecting engine oil temperature. Background technique [0002] In the past, the oil temperature detection of diesel engines generally used a mechanical thermometer, or a thermometer with a pointer driven by a cross coil, or an instrument with an LED display. These instruments mainly have the following determinations: 1. The mechanical thermometer is not only unable to perform remote data transmission, but also has a large deviation from the ideal fitting line for the output voltage of the sensor within the working temperature range, resulting in poor linearity; in addition, the mechanical thermometer The mechanical wear of the thermometer is large during the working process, and the service life is short; 2. The cross coil uses a hairspring as a damping and zero return. Due to the typical nonlinearity of the hairspring, the i...

AI Technical Summary

Problems solved by technology

These instruments mainly have the following determinations: 1. The mechanical thermometer is not only unable to perform remote data transmission, but also has a large deviation from the ideal fitting line for the output voltage of the sensor within the working temperature range, resulting in poor linearity; in addition, the mechanical thermometer The mechanical wear of the thermometer is large during the working process, and the service life is short; 2. The cross coil uses a hairspring as a damping and zero return. Due to the typical nonlinearity of the hairspring, the indicated temperature value is nonlinear on the dial. The correction is difficult, resulting in poor overall linearity of the thermometer. Because the scale line of the thermometer driven by the cross coil uses a nonlinear scale to adapt to its nonlinear characteristics, it is not suitable for people's linear way of thinking. The thermometer drives the pointer through the hairspring of the cross coil Resetting, due to the reciprocating movement of the hairspring, will reduce its elasticity and service life, which will eventually lead to a short service life of the entire instrument, and its life will be shorter in harsh engine environments; 3. The instrument displayed by LED does not conform to the habits that users have formed. Many engine manufacturers do not use LED temperature gauges

In addition, the linear adjustment and zero point and full scale adjustment of the above three thermometers are generally adjusted manually by potentiometers. This method requires repeated adjustments to meet the corresponding accuracy requirements. The adjustment process is very troublesome, and the adjustment accuracy and repeatability are also poor. ; And the debugging time is generally more than 30 minutes per unit, and the parameters change over time, which will easily lead to zero and full-scale drift, as well as changes in linearity

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