| 摘要 |
An electronically controllable gas valve, e.g. for a burner, comprises a housing (2) having a gas inlet (4) and a gas outlet (6) connected by an opening (8) closable by a flow restrictor member (12) of a valve member (10). A shaft (14) of the valve member carries a permanent magnet (20), which is adapted to interact with a control coil (24) on the housing to which a variable electrical signal is provided to vary the force tending to move the flow restrictor member (12) out of engagement with its valve seat (8a) against the closing force of a control spring (22) acting between the housing (2) and the permanent magnet (20). Pressure feedback means (46, 42, 40, 44) may be provided (see Fig. 2) to produce a constant pressure output. The valve may include a safety shut-off mechanism (32, 34, 36). In an alternative, the permanent magnet is mounted on the housing and the shaft carries the control coil or an electromagnet. <IMAGE> |
