thermistors

• Thermistor

  A type of resistor whose resistance decreases as temperature increases
• As temperature increases

  Resistance of a thermistor decreases
• Applications of thermistors

  • Thermostats
  • Computers (to control fan speed)
• How a thermistor controls a fan in a computer

  1. At low temperatures, high resistance of thermistor means low current and low potential difference across fan, so fan runs at low speed

  2. At high temperatures, low resistance of thermistor means high current and high potential difference across fan, so fan runs at high speed
• Other applications of thermistors

  • Incubators for premature babies (to detect temperature drops and turn on heating)
• Thermistors are extremely useful devices