liacs [hw] jan 2015 actuators. devices – machines – apparatusses electrical control of physical...

liacs [HW] Jan 2015

actuators

devices – machines – apparatusses electrical control of physical events

• light– lamp– led– lcd

• movement– electromagnetism– coil, relay– motor– servo– speaker– piezo

• heat– nitinol

how much power / how many Watts

• one Watt is the rate at which work is done when an object's velocity is held constant at one meter per second against constant opposing force of one newton

• one Watt is the rate at which work is done when one ampere (A) of current flows through an electrical potential difference of one volt (V)determined by both voltage and current: P[W] = U[V] * I[A]

• relations between physical quantities: hyper physics• examples

– earphone 10..100 milliWatt– LED: 50 mW– resistor: 0.25 W ( V * I < 0.25)– relay: 200…500 mW– power LED 1W– human: 100..200 W– lamp 1…1000W (1 KW)– car: 9KW (Citroen 2CV) .. 880KW (Bugatti, 2012)

Output device Amperes Volts Watts ac/dcvu meter 1E-04 1 1E-04 dcled 0.02 2.2 0.05 dcheadphone 0.05 3 0.15 acelectromagnet small 0.1 5 0.5 dcsmall toy motor 0.1 5 0.5 dcservo (light) 0.2 5 1 dcPC fan 0.1 12 1.2 dcstepper motor small 0.5 5 2.5 dcservo (heavy) 2 6 12 dcstepper motor large 2 12 24 dccooling fan 0.2 240 48 acautomobile headlight 5 12 60 dcincandescent lamp 0.25 240 60 acelectromagnet large 5 24 120 dcPA speaker 15" 5 40 200 acvacuum cleaner 6 240 1440 acelectric heater, stove 10 240 2400 ac

Arduino output power: board +5V: max. 300mA .. 1A @ 5Vsingle output pin: max 40..70mA @ 4V

light

LED matrix

led strips / chains – adafruit – sparkfun - ebay

•RGB pixel addressable (shift register)•RGB strip: connected per color•common anode(+) / common cathode(-)•constant current driver / buck regulator

• PWM - pulse width modulation

percieved brightness is not linear to duty cycle

• led PWM controllersadafruit 12- or 16 bit PWM– better dynamic range than the 8 bit PWM

from Arduino– 2 wire interface (SPI)– high speed refresh w/o using processing

power– software selectable led current control– general brightness control

TSOP1738 / 1736infrared receiver @38(36)KHz

switching 240V AC (mains)

Arduino remoteswitch library / 433MHz Tx moduleor hack: www.paulk.nl/actionremote

solid state relay-zero cross switching-no sparks-quiet-easy interface (LED)

electromagnetism

relay

DC Motor Rotation

http://hyperphysics.phy-astr.gsu.edu

motor controlled events– position (wheel, cable, belt, rope)– rotation– force (linear motor)– lock / unlock– vibration (pager)– air stream (fan)– pressure (hydraulics)– fluids (pump)

motor type– RPM, geared / ungeared– AC / DC– power ( Watts, NM )

how to get one– video recorder, dvd player, printer, scanner, disk drive– 250AC household: mixer, fan, – toy– tools (electric screwdriver, drill)– RS components– Pollin surplus, Germany

servo

-needs a continuous series of pulses-arduino library (Servo) available-may need >> 300mA current (up to 2A) when blocked or loaded-use extra supply + voltage regulator, common ground

stepper motor

unipolar / bipolar operation

• motor control – LN2003/2803 : on/off control

• transistor darlington array• 8 x 500mA max• up to 30V

– L293 : direction and on/off, low power• dual H-bridge• max 500mA / output• http://www.ti.com/lit/ds/symlink/l293d.pdf• L293D has internal protection diodes

– L298• dual H-bridge• http://www.st.com/st-web-ui/static/active/en/resource/technical/document/

datasheet/CD00000240.pdf• max 40V, total current 4A

– pololu controller• supports microstepping• current control, pot adjustable• L/R en Step inputs (only 2 wires + GND)• http://www.pololu.com/product/2128

L298 breakout board

soundlaser (mirror)non-newtonian fluidarduino synth

speaker

• muscle wire - nitinol

good: no moving parts, changes length or shape, silentbad: takes high current, gets hot, slow release, one way