Blank PCB for Single Channel Inductive Loop Vehicle Detector

Inductive Loop Detector works by detecting an inductance change in wire loop (coil) that is buried in road. It does that by measuring the frequency of the internal oscillator which powers the mentioned coil. When a metallic object moves over the coil it changes its inductance and that in turn changes the oscillator frequency which is measured by the microcontroller.

It is used for vehicle access control at door and barrier controls, for monitoring the occupancy and for vehicle counting in parking garages, for traffic light installations and traffic controllers, for direction and speed detection of vehicle traffic (if dual channel version is used), in car-wash plants, etc.

Specifications

· Tuning: Automatic

· Detection type: Presence/Pulse

· Presence time: Adjustable in 4 steps (default: 11 min, 33 min, 55 min, infinity)

· Pulse duration: 100 ms / 500 ms

· Signal filtering: Adjustable in 4 steps (LOW, MED-LOW, MED-HI, HI)

· Coil/loop inductance: 20 uH – 1000 uH

· Frequency range: 40 kHz – 140 kHz

· Frequency adjustment: 4 steps (LOW, MED-LOW, MED-HI, HI)

· Sensitivity: 0.001% - 0.5% digital in 8 configurable steps

· Detection speed: <10 ms (with LOW filtering stage and loop frequency of 40 kHz)

· Startup time: ~8 sec

· Power supply: 7-40 V DC / 5-28 V AC

· Current consumption: ~0.035 A

· Protection: Galvanic isolation + gas discharge tube for lightning protection

Package list

· PCB x1

Wiki & External links

· Project page with schematics and firmware

More details