Magnetic Polarity Detector
The report investigates the translation of invisible magnetic forces into visual electronic signals. This application allows you to explore the scientific foundations, component specifications, and engineering trade-offs involved in detecting magnetic polarity.
Primary Goal
Distinguish between magnetic North and South poles via discrete LED indicators with zero latency.
Detection Type
Dual-mode operation: Digital (Threshold Switching) and Analog (Intensity-based flux density).
Build Team
Engineering collaborative: M. Hatem, Y. Abdallah, M. Mansour, M. Mohamed.
The Hall Effect & Lorentz Force
This section presents the relationship between magnetism and electricity. When charge carriers move through a semiconductor and a magnetic field is applied perpendicular to their motion, the Lorentz force pushes electrons to one side.
Formula Simulator: VH = (I * B) / (n * q * t)
Interactive Transfer Function Visualizer
Hardware Inventory
Below is the core Bill of Materials derived from the report, highlighting the specific sensors and their functional differences.
A3144 Hall Switch
A digital-output IC. It remains 'inactive' until a threshold flux is reached, triggering a sharp state change. Ideal for binary detection.
SS49E Analog Sensor
Provides a proportional voltage relative to the magnet distance. Essential for mapping field intensity via LED brightness.
LM7805 Regulator
Protects sensitive sensors from voltage spikes by regulating the 9V battery input to a constant 5V DC supply.
Physical Logic: Back-to-Back Mounting
Since individual digital sensors (A3144) are typically unipolar, the report highlights a creative engineering solution: mount two sensors in physical opposition to detect both North and South magnetic fields using a single indicating panel.
SENSOR ALPHA
Branded face: Forward
SENSOR BETA
Branded face: Backward
๐งฒ
Circuit Architecture Design
A side-by-side comparison of the two primary design strategies outlined in the technical documentation.
Strategy Alpha
Dual Switch Topology
- โ Sharp binary response with high noise immunity.
- โ Direct sensor-to-LED interfacing (Simplified PCB).
- โ Zero indication of field strength or proximity.
Strategy Beta
Analog Driver Topology
- โ Proportional LED brightness (visual distance mapping).
- โ Detects absolute flux density gradients.
- โ Requires transistor amplification to handle LED current.
Implementation Protocol
Power Plane
Regulate 9V to 5V via LM7805. Ensure common ground between all ICs.
Logic Termination
Pull-up 10kฮฉ resistors are mandatory for A3144 to prevent floating states.
Output Stage
Sink LED cathodes to sensor output pins for active-low triggering.
Engineering Tolerance Calculator
Adjust the circuit parameters to verify safety margins for the hardware components.
๐ก๏ธ Regulator Thermal Dissipation
Calculated Power (W):
0.16 W
Condition: Optimal operating range
๐ก LED Logic & Current
Resulting Forward Current:
13.6 mA
Recommended: 10mA - 20mA for visibility.
Industrial Utility
ABS Systems
Detection of magnetic 'teeth' on wheel hubs to monitor rotational velocity.
BLDC Motors
Precise rotor position sensing for electronic commutation switching logic.
Current Measurement
Non-invasive amperage tracking via magnetic flux leakage mapping.
Sortation Logic
Automated sorting of components based on magnetized orientation markers.
Critical Troubleshooting Logic
Unstable Indicators
Often caused by 'floating' inputs. Ensure the 10kฮฉ pull-up resistor is bridging Vcc and the output pin to maintain logic HIGH when magnet is absent.
No Polarity Delta
Confirm physical sensor orientation. One sensor must be inverted (flipped 180ยฐ) relative to the other to respond to opposing flux vectors.
Thermal Runaway
If the regulator is overheating, verify the LED current limiting resistors are >= 220ฮฉ. Avoid excessive input voltages above 12V DC.