Temperature Sensing

• Integrated Circuit– PROs:

• Most Linear• High Output• High Accuracy• Inexpensive

– CONs:• Power Required• Slow• Self Heating• Not meant to be used

outdoors

Temperature Sensing

• Thermistor– PROs:

• High Output

• Fast

• Two Wire Ohm Measurement

– CONs:• Non Linear

• Limited Temperature Range

• Fragile

• Current Source Required

• Self Heating

Temperature Sensing

• RTD– PROs:

• Stable• Accurate

– CONs:• Expensive• Current Source

Required• Small ∆R• Self Heating

Temperature Sensing

• Thermocouples– PROs:

• Self Powered• Simple• Rugged• Inexpensive• Wide Temperature

Range

– CONs:• Non-Linear• Low Voltage• Sensitivity

Switches

Lower Limit Switch

Upper Limit Switch

Motor

• I have to ask Krista if she drew an AC motor in the drawings she did (which we were going to use) or not. If she doesn’t have a motor in her slides, I will use the 12VDC motor. Otherwise, I will put an AC motor in the presentation for now.

Microcontroller

• Freescale HCS08– 10bit analog to digital

converter– Ease of use– Inexpensive– Available Code

Electronics Overview???

Microcontroller

TemperatureSensor

Upper LimitSwitch

Lower LimitSwitch

Motor Driver

Motor