Sensitive Hall-Effect Switches & Linear Hall Sensor: Theory, Operation, and Applications

A3144SENSITIVE HALL-EFFECT SWITCHES &AH3503 503 Linear Hall sensor TYWu

Hall Effect • VH = I * B / (n * e * d)

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.

Experiment • https://www.youtube.com/watch?v=bnOd8f5Vev0 • https://www.youtube.com/watch?v=aXe92lWaJAw • http://www.hobbytronics.co.uk/arduino-tutorial11-hall-effect

? 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); }

Sensitive Hall-Effect Switches & Linear Hall Sensor: Theory, Operation, and Applications