Thermal convection based accelerometer and heating control method therefor

A thermal convection based accelerometer, comprising:

• a body having an enclosed cavity;
• and
• a heating control circuit configured for controllably heating the enclosed cavity and comprising:
• a heating resistor configured for heating the enclosed cavity;
• a heating control switch configured for powering on or off the heating resistor;
• a temperature-control thermocouple configured for sensing a temperature in the enclosed cavity and generate a temperature voltage signal;
• an amplifier coupled to the temperature-control thermocouple and configured for amplifying the temperature voltage signal to obtain an amplified temperature voltage signal;
• a modulator configured for converting a voltage difference between the amplified temperature voltage signal and a reference voltage signal into a digital sequence;
• a heating power adjustment module coupled to the modulator and configured for obtaining
• a heating power adjustment factor representing the voltage difference according to the digital sequence;
• a heating power determining module coupled to the heating power adjustment module and configured for obtaining a heating power control parameter based on the heating power adjustment factor and an initial heating power factor;
• and
• a conversion module coupled to the heating power determining module and configured for converting the heating power control parameter into a switch control signal for turning on or off the heating control switch;
• and
• wherein a value of each digital bit in the digital sequence is one of a first integer value and a second integer value, and a sum of the first integer value and the second integer value is 0;
• the heating power adjustment module is configured for obtaining a sum of each group of digital bits in the digital sequence, and then multiplying the sum by a predetermined gain to obtain the heating power adjustment factor, wherein each group comprises N digital bits and N is a natural number greater than or equal to 2;
• and
• the heating power control parameter is a sum of the heating power adjustment factor and the initial heating power factor.