260 likes | 315 Views
A3144 SENSITIVE HALL-EFFECT SWITCHES & AH3503 503 Linear Hall sensor. TYWu. Hall Effect. V H = I * B / (n * e * d) F m : Lorentz force. Theory. The Hall switch is characterized by the magnetic switching points BON (or BOP ) and BOFF (or BRPN). Theory.
E N D
A3144SENSITIVE HALL-EFFECT SWITCHES &AH3503 503 Linear Hall sensor TYWu
Hall Effect • VH = I * B / (n * e * d) • Fm: Lorentz force
Theory • The Hall switch is characterized by the magnetic switching points BON (or BOP ) and BOFF (or BRPN).
Theory • If the magnetic flux exceeds BON , the output transistor is switched on; if it drops below BOFF, the transistor is switched off. The magnetic hysteresis BHYS is the difference between the switching points BON and BOFF.
Pins • Pinning is shown viewed from branded side
Electrical Characteristics • At VCC = 8 V over operating temperature range.
Electrical Characteristics • Each device includes a voltage regulator for operation with supply voltages of 4.5 to 24 volts • Reverse battery protection diode • Quadratic Hall-voltage generator • Temperature compensation circuitry • Small signal amplifier, Schmitt trigger, and an open-collector output to sink up to 25 mA. With suitable output pull up, they can be used with CMOS logic circuits
A3144.pde int sensorPin = 2; int counter = 0; boolean sensorState = false; void setup() { Serial.begin(9600); pinMode(sensorPin, INPUT); // Pull Up digitalWrite(sensorPin, HIGH); }
A3144.pde void loop() { if(magnetPresent(sensorPin) && !sensorState) { sensorState = true; printMessage("Magnet Present"); } else if(!magnetPresent(sensorPin) && sensorState) { sensorState = false; printMessage("Magnet Gone"); } }
A3144.pde void printMessage(String message) { counter++; Serial.print(counter); Serial.print(" "); Serial.println(message); } boolean magnetPresent(int pin){ return digitalRead(pin) == LOW; }
Connection • Figure
Execution • Snapshot
AH3503 503 • FEATURES • Extremely Sensitive • Flat Response to 23 kHz • Low-Noise Output • 4.5 V to 6 V Operation • Magnetically Optimized Package
AH3503 503 • Pins
AH3503 503 • Block Diagram
AH3503 503 • Electrical Characteristics
AH3503 503 • Operation • The output null voltage (B = 0 G) is nominally one-half the supply voltage. • A south magnetic pole, presented to the branded face of the Hall effect sensor will drive the output higher than the null voltage level. • A north magnetic pole will drive the output below the null level.
Applications • Notch Sensor, etc.
Videos • https://www.youtube.com/watch?v=bnOd8f5Vev0 • https://www.youtube.com/watch?v=aXe92lWaJAw • http://www.hobbytronics.co.uk/arduino-tutorial11-hall-effect • https://www.youtube.com/watch?v=ujc6pjftZ_w&nohtml5=False
? Experiment • Arduino
Experiment • Arduino const int hallPin = 0; // the hall effect sensor pin const int ledPin = 11; // the LED pin int volt; void setup() { pinMode(ledPin, OUTPUT); pinMode(hallPin, INPUT); }
Experiment void loop(){ int luminance; volt = analogRead(hallPin); luminance = 0.5*abs(volt-512)-1; //volt=0~255 analogWrite(ledPin, luminance); }
Project • Bike Speedometer • https://www.youtube.com/watch?v=i3k7gF9Xud0&nohtml5=False
Reference • http://ezphysics.nchu.edu.tw/ccp/magntostatics/m4.htm • http://hyperphysics.phy-astr.gsu.edu/hbase/magnetic/hall.html