智能烘箱温度控制器设计-英文翻译(5)

circuit is very simple. MAX6675 adopted the 12 bit ADC, the temperature measurement range of 0-1024 ℃, within the range of 0-700 ℃ conversion accuracy of plus or minus eight words, power supply, 3.0-5.0 V, a resolution of 0.25 ℃, the conversion time about 0.17 s. MAX6675 encapsulated by 8 feet SO, figure 2-4 for the pin arrangement diagram, T + K type thermocouple's positive electrode (alloy), T - type K thermocouple's negative (nickel or nickel aluminum silicon alloy); CS for high levels of selected signals from this transformation start temperature, low electricity at ordinary times allows data output; SCK for clock input; SO for the data output side, 12 data after temperature conversion output by way of the feet to SPI.

Figure 2-4

Temperature transformation: MAX6675 inside is hot I will signal conversion to and compatible with the voltage signal conditioning amplifier, the ADC input channel and T + T - input end connected to the low noise amplifier A1, to ensure the accuracy of detecting input, at the same time use the thermocouple wires from the interference source. Thermocouple thermoelectric potential output by the low noise amplifier A1 amplifier, after A2 voltage follower buffers, again be sent to the ADC input end. In converting temperature voltage value equal to the value before, it need to