Vehicle Ground Loop Detection Circuit

The electronics unit applies alternating current electrical energy onto the wire loops at frequencies between 10 khz to 200 khz.

Vehicle ground loop detection circuit.

Leads to each loop. Loop vehicle detector. If the inductive loop is placed correctly it will detect vehicle open gate and keep it open until the vehicle clears the gate. How to make a vehicle ground loop detection sensor circuit duration.

In either case the loop or the extension cable must be replaced. If the resistance is less than 50 megohms the loop is shorted to ground and must be replaced. Good practice dictates multiple loops and detectors in this situation. The presence of a car lowers the inductance of the loop embedded in the road which then alters the operating frequency of the circuit.

An insulated electrically conducting loop is installed in the pavement. Direction dependent vehicle detection. When a vehicle with metal parts approaches or stops within the wire loop the frequency of the oscillating circuit changes. Vehicle detection loops called inductive loop traffic detectors can detect vehicles passing or arriving at a certain point for instance approaching a traffic light or in motorway traffic.

This project an induction loop vehicle detector from 1983 is really a large metal detector buried in the ground. Most loop detectors have built in diagnostics which can identify problems in the detection system. In other words the relay circuit output will be closed opened the entire time that a vehicle is present over the loop and does not switch again until the vehicle drives away. If the resistance is less than 50 megaohms the loop is shorted to ground.

The wire loops embedded in the ground act as the inductive mechanism for a high frequency oscillating circuit. This loop detector is responsive highly sensitive and utilises sophisticated software algorithms which adapt to prevent false triggering. Best performance is obtained by shortening the leads as much as possible and providing the lowest impedance to ground. A series of blinking led s is an indication of possible loop problems.

The common either the bolt green wire or center clip connection must be connected to earth ground. One 140d130s250sg2n0 140d130s250sw3n0 is used on each loop detector circuit to be protected.