advanced electronic components

8/2/2019 Advanced Electronic Components

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Introduction to some

advanced electronic

components

Physical Computing 2009

By Farshid Jafari Harandi

Todays topics

More on sensors as input

More on actuators as output

More info on Transistors,

Relays, LEDs

Pictures from:

http://www.robotroom.com/Pumpkin3.html

http://www.parallax.com/

http://www.psartus.com/products/actuators.htm


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Sensors as input

New sensors bring opportunities todevelop initiative products/prototypes.

iPhone games with accelerometershttp://www.youtube.com/watch?v=_brEsQlJlnE

Gyromousehttp://www.youtube.com/watch?v=tj2vxWkHW1Q

How sensors work

Sensors measure real world factors and translatethem into corresponding electric signals.

Outputs such as

Analog voltage

Current

PWM output

Serial interfaces

Inputs such as

Temperature

Acceleration

Magnetic field

Translate


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How to read sensors?

Analog voltage / current:

Analog voltage (0 to 5v) canbe read by Arduinos analoginput

Current can be converted toanalog voltage

Picture from:

http://archives.sensorsmag.com/articles/0900/17/main.shtml


PWM:

Varying duty cycle

Read by Pulsein(); command


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Serial interfaces:

Transfer data using less number of wires

Ready-made and built in codes to read them:

I2C/Two wire UART (Soft /Hardware)

1 Wire

SPI

CAN

Sensors

Microphone

Realtime Audio Processing

Loopback Phasor

Reverb

Picture and reference:

http://interface.khm.de/index.php/lab/experiments/arduino-realtime-audio-processing/


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Sensors

Distance measurement

Ultrasonic (Parallax Ping, 2cm-

3m, Serial interface)

IR distance meters (Sharp

GP2D12, 10-80cm, Analog)

3D Laser Scanners (Hokuyo URL-

04X, 240 2cm-5.6m,Uart)

Pictures from:

http://www.wanyrobotics.com/

http://www.trossenrobotics.com/


Sensors

Presence detectors Passive infrared sensor (Human, 7m,

Digital)

Reed switch (Magnetic, 5mm, Digital)

IR proximity sensor (IR, 2-10cm, Digital)

Pictures from:


http://www.dextermag.cn/

http://www.pololu.com/


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Sensors

Position sensor GPS

LS20031

Open space

5Hz

UART

Absolute position

Picture from:

http://www.sparkfun.com/

Sensors

Compass sensor

Digital Magnetic compass

CMPS03

Uses the Earth magnetic field

Outputs timing pulse and I2C

Picture from:

http://www.robot-electronics.co.uk/acatalog/Whoops.html


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Sensors

Tilt sensor

Mechanical tilt switch

Two contacts and a

metal ball inside

Acts like a switch

Picture from:

http://www.coolcomponents.co.uk/

Sensors

Pitch/yaw/roll sensor

3 Axis Accelerometer

MMA7260QT

1.5/2/4/6 g

Angle in steady state

3 Analog outputs

Pictures from:


http://en.wikipedia.org/


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Sensors

Gyroscopic effect sensor

1-Axis Gyroscope

LISY300AL

300/s

Rate of rotation around a particular axis

Outputs analog voltage

Pictures from:


More on Gyros and Accelerometers:

http://diydrones.com/profiles/blog/show?id=705844:BlogPost:41145&page=1#comment-705844_Comment_41399

Sensors

Temperature

Temperature meter

LM35

40C to +110C

10 mV/Deg C

Outputs analog voltage

Picture from:

http://www.facstaff.bucknell.edu/


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Sensors

Temperature

Resistance temperature detector, a

variable resistor

Thermocouple, millivolt level voltage

Thermistor, a variable resistor

More sensors

Flow meters

Smoke/gas detectors

Optical interrupters

Vision/camera

Weight

And even more


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Concerns with sensors

Calibration/ offset

Noise

Drift

Resolution

Hysteresis

Non-linearity

Actuators

Brushed/brushless/servo/stepper DC motors

Single/three phase AC motors

Linear motors

Hydraulics

Pneumatics

Solenoids or magnetic actuators (attraction/repulsion)

etc.


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Concerns with actuators

Providing high amounts of current

Taking care of back-EMF

Timing

And more

Back EMF

With inductive loads:

Place a fast recovery diode in

reverse bias across the load

Examples of inductive loads:

Motors

Relays


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Current amplification

Relays

Transistors: BJT or

MOSFET

Drivers

Pictures from:

http://en.wikipedia.org/wiki/Relay

http://en.wikipedia.org/wiki/H-bridge

http://en.wikipedia.org/wiki/Transistor

Current amplification guide

Load draws more than

40mA?

Current amplification

is needed


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Loads with less than 200mA

Use transistors such as:

2N2222

BC547

For resistive loads

diode can be omitted


Loads with less than 500mA

Use ICs such as:

ULN2003 ULN2803

Internal protection

diodes


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Loads with more than 500mA

Use transistors such as:

BD167 up to 1.5A

2N3055 up to 15A(needs a different resistor)

IRF540 up to 33A(requires V+ to be more than 12V)

IPS series


Loads with more than 500mA

Use relays

Note that some

relays draw

more than 40mA!


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LED/resistor matching

How to calculate the proper resistor for a

Single LED

Number of LEDs

In series

In parallel

Tips

Loose connections, use soldering!

Use multimeter to check continuity


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Sources

Sensors :

http://en.wikipedia.org/wiki/List_of_sensors

http://en.wikipedia.org/wiki/Sensors

Actuators :

http://www.eod.gvsu.edu/eod/mechtron/mechtro

n-145.html Modern Control Technology - Components and

Systems, 2nd edition, Christopher T. Kilian,ISBN : 1401858066

Questions ?


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