Abstract: The penetration depth of a machining laser beam into workpiece is continuously monitored in that a measuring laser beam is directed onto the vapor capillary that is generated in the workpiece by the machining laser beam.

Abstract: A position display instrument for light spot display on a map of the position of vehicles, in particular aircraft or helicopters. The instrument comprises a flat map holder for accommodating and holding map sheets in an exact position, a light transmitter located below the map holder for producing a light spot on the map sheet and movable in two coordinates by positioning means, a microcomputer to which the grid coordinates of the vehicle position are applied from a navigational computer and by which the positioning means are controlled, a memory for storing map data, said memory cooperating with the microcomputer, and display means which is connected to the microcomputer and by which the map sheet or map field required for the respective grid coordinates is displayed.

Abstract: A stepping motor turns 45.degree. for each step in response to a digital control signal different than the signals for other step adjacent thereto. An angle sensor produces a digital position indicating signal for sectors centered about the step positions and of the same magnitude as the angle between motor steps. The position indicating signal for a sector corresponds to the digital signal of the motor step that falls within that sector. An evaluation circuit comprising a microprocessor produces an error signal when, after a predetermined elapsed time after receipt of a control signal, a corresponding position indicating signal is not received. The evaluation circuit also checks for correspondence of signal within a minimum time after receipt of a control signal, and failing to find such correspondence assumes that the motor has not performed the directed step.