Abstract: An unbalanced vibrator for compacting concrete components during their manufacture has a vibrating table, unbalance shafts arranged on the vibrating table, and electronic motors allocated to the unbalance shafts in order to drive them, wherein the electronic motors have a device for the control and/or regulation of the rotational speed and/or the relative phase position of the unbalance shafts. The unbalanced vibrators of this type should be adjustable in an extremely rapid manner, in order to shorten manufacturing processes. For this purpose the electronic motors are designed as servo-motors and are provided with a device having sine-cosine transmitters, which determine the angular position and rotational speed of the unbalance shafts, such that the entire regulation/control can occur in a fully digitalized manner.

Abstract: In a method for quality control during production of concrete blocks by bringing a concrete mortar into an upwardly open hollow mold with a solid peripheral wall for forming at least one molded blank placed on a flat supporting surface, a thickness of a molded blank is determined contact-free for testing the dimensional stability. The volume of the molded blank is determined from the determined thickness and the cross-section of the hollow mold. The density is obtained from the weight and volume, which is a criteria for strength and resistance testing of the molded blank. Finally, the appearance of the molded blank is determined by at least one video camera and compared with the appearance of faulty molded blank to determine the molded blanks with surface errors. All results of the height, density and surface measurements can be used for control of the production arrangement.