usedd in parking system, high way traffice system to detect, count cars and realise te direction of cars.

VD108 is used for wherever vehicles have to be detected, for example for monitoring and safe-guarding accessways or for counting vehicles. The output signal can be used for controlling door and gate drive mechanisms, operating barriers, controlling traffic light systems or activating card dispensers in parking lots. VD108B only has one TTL-level output, which is unlimited.

specification:

Supply voltage: 220, 110, 24, and 12V AC
Operating voltage: 7 to 12V DC at 100mA
Frequency range: 20 to 170kHz
Sensitivity: 0.02 to 0.2% (4 level can be adjusted)
Respond time: 100ms
Automatic drift compensate
Encapsulation: stranded reply encapsulation
Loop inductance: 50 to 500Hz (include connecting wiring), ideal: 100Hz to 300kHz
Loop conjunction: wiring maximum 100m, twisted at least 20 times per meter total
Resistance: 10 ohms
Storage temperature: -40 to 85°C
Humidity: 95% RH
Dimensions: 27 x 21 x 37mm