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AS ICT
Have an understanding of how organizations use ICT.
Be able to describe a number of uses, giving the hardware and software requirements.
Be able to describe the applications that these uses can be put to.
Uses microprocessors or computers to control certain physical conditions, either Keeping them the
same over a period of time or
Varying them according to predefined values/lengths of time
Maintaining constant physical conditions: Air conditioning systems Central heating systems Refrigeration Medical applications: Intensive care Car Manufacture plants Process Control
Physical conditions (variables) that are controlled by computer/microprocessors include: Temperature Pressure Humidity Light Moisture etc
Numeric KeypadPush buttons/switchesTemperature sensorMoisture sensorPressure sensorLight sensorContact Switch
ADCDACTimerAlgorithms to
compare data from sensors to predefined values or ranges
RobotFansHeatersBoilersBuzzer/alarmLightsLED display
Sensors are needed to monitor temperature (continuously)
Microprocessor compares the temperature with a preset value/range
Depending on result microprocessor causes the fan motor to speed up or slow down
Fan motor switched on or off
Inputs Processes Outputs
Buttons/touchscreen
Sensors monitor temperature continuously
LED display
Contact switch Analogue data from sensors converted to digital using ADC
Fan
Temperature sensor
Temperature compared to preset range/value
Buzzer
Pressure sensor Signal sent to actuator to switch fan on or off
Output directly affects the input
No human intervention is necessary
Good for situations where control is required 24/7, or in a dangerous/difficult environment
Sensors continuously monitor temperature
Microprocessor compares the temperature with a preset value/range
Depending on result microprocessor causes the fan motor to speed up or slow down
Fan motor switched on or off
Inputs Processes Outputs
Contact switch (door)
Sensors monitor temperature continuously
LED display
Pressure sensor (door)
Analogue data from temperature sensor converted
to digital by ADC
Compressor
Number pad or dial Temperature compared to preset range/value input by
user
Buzzer
Temperature sensor
Signal sent to actuator to switch compressor on if temp
is too high
Signal sent to actuator to switch compressor off if temp
is OK
Sensors are needed to monitor temperature (continuously)
Microprocessor compares the temperature with a preset value/range
Microprocessor controls two actuators one opens gas valves in the boiler the other switches the pump on
Inputs Processes Outputs
Touch screen Sensors monitor temperature continuously
LED display
Number pad or dialAnalogue data from
temperature sensor converted to digital by ADC
Radiators
Temperature sensor
Temperature compared to preset range/value input by
user
Signal sent to actuators to switch pump on & open valves
if temp is too low
Signal sent to actuator to switch pump off/close valves if
temp is OK
BoilerHot water cylinderPumpRadiatorsTemperature sensors
CompressorsHeatersCondensersPumpsFansTemperature sensorsMoisture sensorsPressure sensorsLight sensors
Control software
