Abstract: In a preferred embodiment, a reversible DC power supply having an audible alarm, especially for use with electrochemical metallizing equipment. The audible alarm is electrically connected directly to the controls of the power supply so that when the power supply is placed in its "reverse" mode, the audible alarm will continuously sound, thus alerting the operator that the power supply is in that mode. In other embodiments, reversible electric tools, such as drills, may be provided with an audible alarm to indicate when they are in their reverse states.

Abstract: An installation is provided for carrying out localized electrolytic surface treatment, of the type including an electrolyte reservoir (22) and pumping means (19) adapted for feeding the electrolyte to an anodic equipment (1) able to be placed in contact with the surface of the work piece (P) to be treated, a thin electrolyte flow space then being provided, in said equipment, between the surface of the anode (5) and said surface to be treated, the anode (5) and said work piece (P) being connected to the terminals of a DC voltage source, characterized in that it includes suction means (4, 25) connected to said equipment (1) for bringing the electrolyte back to said reservoir (22) after it has passed through said flow space.