Mechatronics - On/Off Temperature Control

One of case studies at Mechatronics class at Columbia University taught by Dr. Fred R. Stolfi. This case study is a dynamic system investigation of an important and a common mechatronic system: a thermal close-loop system.

The main apparatus includes:

  • A microcontroller, PIC 16F74
  • A resistive heater (SRMU 100202P)
  • Two temperature sensor (AD590 and AD22100)
  • A fan.

The film of On/Off temperature control:

The specification of resistive heater:

Specifications Value
Manufacturer Omega Engineering Inc
Model Number SRMU 100202P
Heater Resistance 350 ohms
Heater Area 4 in2
Heater Thickness 0.1 in

The specification of temperature sensor are listed below:

Specification AD590 AD22100
Rated Temperature Range -55℃ to 150℃ 0℃ to 100℃
Nominal Output at 0℃ 273.2 μA 1.126 V
Nominal Output at 25 0℃ 298.2 μA 1.587 V
Temperature Coefficient 1μA / ℃ 18.43 mV/℃
Absolute Error ± 5.5 ℃ ± 2.0 ℃
Nonlinearity 0.8 ℃ 0.5 ℃

The essential difference is that AD590 (plate) produce a current proportional to temperature while AD22100 (ambient) produce a voltage proportional to temperature.