week 8 1_introduction_to_electro_pneumatics
DESCRIPTION
hydraulic subtopicTRANSCRIPT
Electro-pneumatic Combination of electrical and pneumatic system
Used when the process is repeating and setup cost is low
But
◦ Maintenance – troubleshooting is very complex
◦ Structure – circuit structure is messy when involving complex design
Relay
◦ On/Off switch
Solenoid
◦ Single valve solenoid Double valve solenoid
Pneumatic Circuit Symbol Electrical Circuit Symbol
Y1
Y1 Y2Y1
Didactic
Optical
Inductive
Reed Switch
Inductive Magnetic
Capacitive
Symbols
Connection
Proximity Sensors
• Sensors that are able to detect the presence of nearby objects without any physical contact.
•A proximity sensor often emits:
1) Electromagnetic or electrostatic field
2) A beam of electromagnetic radiation (infrared, etc)
and looks for changes in the field or return signal.
•The object being sensed -> proximity sensor's target.
•Different proximity sensor targets demand different sensors:
Inductive proximity sensor -> metal target.
Capacitive sensor -> high density target
Photoelectric sensor -> reflective target
Proximity Sensors
+18 ~ 30 Volts DC.
0 V
Output
Inductive
Capacitive
Optical
Magnetic
Ultrasonic
Normally open
Normally closed
Symbol
Inductive Sensor
Inductive sensor is used to sense only metal type of object.
ON
OFF
• Detects all conductive materials
• Best conductor is mild steel
• The sensor performance relies on temperature, the target material and its area.
Sensor
Oscillation Amplitude
Sensor output signal
Target Inductive Sensor
ON
OFF
Sensor
Oscillation Amplitude
Sensor output signal
Target Inductive Sensor
ON
OFF
Sensor
Oscillation Amplitude
Sensor output signal
Target Inductive Sensor
ON
OFF
Sensor
Oscillation Amplitude
Sensor output signal
Target Inductive Sensor
ON
OFF
Sensor
Oscillation Amplitude
Sensor output signal
Target Inductive Sensor
ON
OFF
Sensor
Oscillation Amplitude
Sensor output signal
Target Inductive Sensor
ON
OFF
Sensor
Oscillation Amplitude
Sensor output signal
Target Inductive Sensor
ON
OFF
Sensor
Oscillation Amplitude
Sensor output signal
Target Inductive Sensor
ON
OFF
Sensor
Oscillation Amplitude
Sensor output signal
Target Inductive Sensor
ON
OFF
Sensor
Oscillation Amplitude
Sensor output signal
Target Inductive Sensor
Capacitive Sensor
Capacitive sensor is used to sense only high density objects
• Detects all materials with densities higher than air.
• Sensitivity is adjustable
• No suitable to use in dusty environments
Capacitive Sensor
Target
Capacitive Sensor
Capacitive Sensor
Capacitive Sensor
Capacitive Sensor
Capacitive Sensor
Capacitive Sensor
Capacitive Sensor
Optical Sensor
Optical sensor is used to sense only reflective type of object.
Transmitter (T) / Receiver (R)
Optical Sensors
Type : Diffuse
• Detection distance: less than reflex type, actual distance depends on colour and surface smoothness
• Larger targets enables a longer detection distance
• No suitable in dirty environments
T
R
Target
T
R
Transmitter (T) / Receiver (R)
Optical Sensors
Type : Diffuse
T
R
Target
Transmitter (T) / Receiver (R)
Optical Sensors
Type : Diffuse
T
R
Transmitter (T) / Receiver (R)
Optical Sensors
Type : Diffuse
T
R
Transmitter (T) / Receiver (R)
Optical Sensors
Type : Diffuse
T
R
Transmitter (T) / Receiver (R)
Optical Sensors
Type : Diffuse
T
R
Transmitter (T) / Receiver (R)
Optical Sensors
Type : Diffuse