A3144 SENSITIVE 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