Abstract: A transmitter for a line locator system that controls the electrical current, voltage or power applied to the target line is disclosed. Control of the electrical output of the transmitter can be achieved passively or by means of a feedback control system. A transmitter connected directly to a line can include an operator control and monitoring of current being supplied to a line to be located. Some transmitters include a current regulating circuit that controls current supplied to a line. In some transmitters, feedback controllers and feedback loops are used to regulate output current, voltage or power. Some control loops are based on monitoring currents in circuits; some control loops monitor power output from an inductive mode transmitter antenna. An inductively coupled transmitter with power output control is also disclosed.

Abstract: An underground line locating receiver is disclosed which can determine whether the magnetic field it detects is representative of a line to be located or whether distortions in the magnetic field indicate an anomalous condition, and that therefore the reported line location measurement is suspect.

Abstract: A device with a laser pointer for locating concealed objects is presented. In some embodiments, the device is a line locator. In some embodiments, the device is a marker locator. In some embodiments, the laser pointer can provide an indication on the surface over the concealed object so that the surface can be easily marked. In some embodiments, the laser pointer can be utilized as a range finder to find the distance between a landmark and the device, which can be utilized to triangulate a position of the concealed objects.