| 摘要 |
A metering valve which is particularly advantageous for use in gas mixing devices such as patient ventilators, to accurately control the volume and frequency of gas flow for each gas and to provide a feedback of the actual flow through the valve. A valve (82), actuated by solenoid (164) is connected to the core of a linear variable differential transformer (192). As the valve opens, the core (206) of the transformer (90) moves, causing a change in the output voltage from the transformer. The change in output voltage from the transformer can be interpreted by a microprocessor to discern the actual flow through the valve. Two or more of the metering valves can be used to accurately control the mixture ratios of two or more gases. <IMAGE> |
