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 concrete compaction system includes an unbalance exciter for concrete compaction, a compaction detection device for detecting progress of the compaction in the concrete, and a vibration device for generating a haptic feedback when a prescribed progress of the compaction has been detected by the compaction detection device. An electric motor may drive the unbalance exciter and may be powered by an electric power supply and a converter device for converting an electric current from the electric power supply to a drive current for the electric motor. The compaction detection device may comprise a measurement device for measuring the current drawn from the electric motor. The compaction detection device may also comprise an evaluation device for evaluating the current drawn measured by the measurement device, for determining therefrom the progress of the compaction in the concrete, and for detecting whether a prescribed progress of the compaction has been achieved.

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 work machine includes a working device for generating a working motion; an electric motor for driving the working device; an electric energy storage device for supplying the electric motor with electric current; and a cooling device for cooling the energy storage device. The cooling device comprises at least one fan device for generating a cooling air flow which can be directed over the energy storage device. At least one temperature sensor is provided for detecting a temperature, and a control device is provided for controlling the fan device as a function of the temperature detected by the temperature sensor.

Abstract: A work machine, such as a vibration tamper or a vibratory plate machine, includes a work device such as a ground contact plate, and a drive for driving the work device. The drive has an electric drive motor, an electric power accumulator for supplying the drive motor with an electric current, and an inverter installation for inverting the current from the power accumulator and for supplying the current to the drive motor. A cooling device is provided for cooling the power accumulator and the inverter installation. The cooling device has at least one fan installation for generating a cooling airflow which is able to be guided by way of the power accumulator and the inverter installation. The fan installation has a fan and a fan motor that drives the fan. The fan motor is provided separately from the drive motor of the drive.