Vehicle Loop Detector

Vehicle detection loops: automatic your access control point  Detection loops are typically installed in roadways with security barriers or traffic gate to detect the presence of a vehicle to provide an indication as to a vehicle's presence within the barrier area. This indication is to help prevent the barrier or gate from closing while a vehicle is present. Some loops also provide i nformation to control the barrier's movement. The type of barrier ( barrier gate, bollards, rising beam, drop arms, swing gates, sliding or track gates, traffic arms) and its intended use, should determine which loop function should be used and where they should be located. All loop functions should be a part of an overall traffic flow theory of operation for the particular access point, to ensure proper operations. Email:una8jutai@gmail.com  WhatsApp:+8618179436123 Skype:una0305

How Loop Detectors Work A frequently asked question in the newsgroups is about how the vehicle detectors used in traffic lights and in car parks work. The author designed such a detector too many years ago for comfort and has frequently posted replies to these questions. Here is one of those replies. It is not a definitive treatment of the subject but should give you an overview of how loop detectors work. When you approach a traffic signal or car park boom gate, you may notice a rectangular "scar" where the road surface has been cut with a saw and then re-sealed. This is the sensor loop. The loop consists of several turns or wire buried in the roadway and connected to an electronic circuit which can detect a car passing over it. Normally the loop is about 1m x 1.5m in size. How do the electronics detect the passage of the vehicle over the loop? There are three methods I know of: "Damped Oscillator" The loop is part of an oscillator circuit. The oscillato...