| 摘要 |
Fans are pref. used to blow air inwards and aspirate it outwards, and work with ducts leading to and from the premises to be ventilated, terminating in mouthpieces. A regulator (8) emits a singal when the static pressure in the premises deviates from that of the external air, the signals being received by an adjuster which accordingly increases or reduces the air flow through the blow-in and aspiration units. The regulator comprises a symmetrical, hollow housing body (9) the interior of which is divided by a pliant membrane (10). The centre of the membrane is provided with a contact plate (17) of electrically conductive material, air inlet apertures (13,14) leading to each of the spaces (11,12) separated by the membrane, and on opposite sides of the membrane contact components(15,16) working in conjunction with the plate. Two electrical circuits are provided in which the contact components areintegrated, and each of the circuits is enclosed by the membrane, allowing the contact plate to be moved out of its rest position. Contact leads connect the two spaces in the housing body to the external air and to that in the premises. |
