| 摘要 |
The degree of concrete compaction is controlled by a sensor, which is formed by a small-power leakage transformer, whose magnetic shunt is a form with the concrete mixture. The free movement of the solid parts of the mixture is increasingly limited in the form with the concrete mixture by vibrations, which is reflected in the increased movement of the form vertically. The current and voltage of the secondary winding of the small-power leakage transformer is changed by the increasing movement of the form. The vertical direction of the form is greatest at the total compaction of the concrete mixture as a result of the total limitation of the free movement of the solid parts in this mixture, and the movement does not change any further. This means that the values of the current and voltage of the secondary winding of the small-power leakage transformer do not change and, as these values are continuously compared with the set values of the stabilized current with the voltage, the balance of the comparison and balancing conducting bridge can occur only at the total compaction of the concrete mixture, when the current with voltage of the secondary winding of the small-power leakage transformer does not sink any further. No current comes from the balanced bridge into the switching-off sensor, by which the whole device is switched off.<IMAGE>
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