Transcript Picture Quiz - D&T Within Schools

Duration
2:21
© D&T WITHIN SCHOOLS 2014
INPUTS
21/07/2015
INPUTS
THE INPUT IS WHAT CAUSES THE ELECTRONIC CIRCUIT TO DO SOMETHING
E.G. FLICKING A SWITCH (INPUT) CAUSES AN LED (OUTPUT) TO COME ON
© D&T WITHIN SCHOOLS 2014
INPUTS
21/07/2015
SWITCHES
Switches come in all sorts of shapes and sizes and are used on practically every device to turn it on or off
The main types are as follows:SPST – Single Pole Single Throw – a simple switch with one pole and one contact (like the pictures)
SPDT – Single Pole Double Throw – one pole and two contacts and can be switched to either.
DPDT – Double Pole Double Throw – has two poles and four contacts (like two SPDT, but in one package)
PTMS – Push to Make Switch – push the button to make contact – turn on
PTBS – Push to Break Switch – push the button to break contact – turn off e.g. emergency stop button
© D&T WITHIN SCHOOLS 2014
INPUTS
21/07/2015
SWITCHES
These devices act as switches but are not operated by hand
Tilt Switch – will activate when tilted to a certain degree – e.g. angle of 4x4
Proximity Switch – will activate when it comes within a certain distance of
something else – e.g. reversing sensor on car
Reed Switch – Will activate when a magnetic field is present – used for alarm
circuits on windows and doors
Vibration Switch – will activate when vibrated – e.g. when a window is smashed
Pressure Switch – will activate when pressure is applied – e.g. under a door
mat, so will activate when someone walks on it
© D&T WITHIN SCHOOLS 2014
INPUTS
21/07/2015
SENSORS
Sensors act like switches but activate by themselves when they sense a certain condition
MOISTURE DETECTOR
Will activate when damp or wet
e.g. water levels for flood warnings
LDR Light Dependent Resistor
Will activate when dark or light
e.g. turn light on when it gets dark
and turn it off when it gets light
HEAT SENSOR
Will activate at a certain temperature
e.g. Central heating thermostat
© D&T WITHIN SCHOOLS 2014
INPUTS
Smoke Detector
Will activate when smoke is about
e.g. activate a smoke alarm
21/07/2015
© D&T WITHIN SCHOOLS 2014
INPUTS
21/07/2015