Abstract: A concrete compaction device includes a vibrator housing for immersion in flowable concrete, and an unbalance exciter which is driven by an electric motor and which is arranged in the vibrator housing. A current detection device detects the electric current absorbed by the electric motor. Ann evaluation device determines an operating state of the concrete compaction device based on the electric current that is currently detected. The operating state is selected from the group consisting of: positioning of the vibrator housing in the air, immersion of the vibrator housing in the concrete, performance of a compaction process with the vibrator housing immersed in the concrete, and emersion of the vibrator housing from the concrete. The evaluation device is configured to recognize all of these operating states.

Abstract: A compaction system has a compaction device with an electric motor for generating a compaction movement, an energy device for providing electric energy for the electric motor, a measurement device for measuring the current drawn by the electric motor, and an evaluation device for evaluating the current draw as measured by the measurement device and for determining, from this determination, the compaction progress in the medium being compacted. The evaluation device is arranged at least partly in an external device, spatially separate from the energy device and/or from the compaction device.

Abstract: A piece of equipment which has a ground contact device for working on a ground region located below the ground contact device in the working position of the piece of equipment, a driving device which can be operated by an electric motor in order to produce a working movement of the ground contact device, an electrical energy accumulator, enclosed by a housing, for supplying the electric motor with electrical energy, and a covering device for covering the housing and thus the energy accumulator, which covering device is arranged above the energy accumulator in the working position. The piece of equipment may for example be a tamper, a vibration plate, a roller, or a breaker.

Abstract: An electronic frequency converter is used with a high frequency immersion vibrator in order to compact concrete. The frequency converter comprises a cooling circuit containing a cooling medium; a first heat exchanger which is integrated into said cooling circuit and is used to transmit heat generated in the housing of the frequency converter to the cooling medium; and a second heat exchanger which is integrated into the cooling circuit and is used to outwardly transmit heat absorbed by the cooling medium. The second heat exchanger is received in a vibrator housing of the high frequency immersion vibrator. If the vibrator housing is immersed in concrete, the heat produced in the converter housing can be conducted away to the concrete.

Abstract: The invention relates to an electronic frequency converter (1) which is used with a high frequency immersion vibrator in order to compact concrete. Said frequency converter comprises a cooling circuit (4) containing a cooling medium; a first heat exchanger (3) which is integrated into said cooling circuit (4) and is used to transmit heat generated in the housing (2) of the frequency converter to the cooling medium; and a second heat exchanger (11) which is integrated into the cooling circuit (4) and is used to outwardly transmit heat absorbed by the cooling medium. The second heat exchanger (11) is received in a vibrator housing (6) of the high frequency immersion vibrator. If the vibrator housing (6) is immersed in concrete (12), the heat produced in the converter housing (2) can be conducted away to the concrete (12).