This detector operates on any voltage from 10 to 30 volts AC or DC and draws about 35 milliamp of current with no vehicle on the loop. This micro-sized detector will automatically adjust its sensitivity level when used on different sized loops. The detector loop inductance should be between 20 and 2000 microhenries.
This series of Diablo Controls detectors are covered by United Stated parent. Patent number US 7,132,959 “Non-Interfering Vehicle Detection.”