| 摘要 |
The proposal is for an electro-thermal setting drive for control and shut-off fittings in heating and air-conditioning installations, in which the side associated with the working piston (11) of a thermal expansion element (1) rigidly supported in a housing (8) can be heated via a PTC resistor (3). A shared PTC resistor (3) is fitted between two expansion elements (1, 2) arranged in series with opposite working directions of their pistons (11,21). The thermal efficiency is improved by such an arrangement. |
