| 摘要 |
1. Rapid response current-flow converter for dosing a fluid flow and particularly a gaseous flow to a receiving means (6), particularly a load handling means such as a jack, or a distribution device ; said converter comprising several electro-valves (1, 2) each controlled by an electronic control means (3, 4) and connected by their inlet to a pressurized fluid reservoir (5) and by their outlet to receiving means (6) ; and by a sensor means (7) measuring a parameter which is proportional to the flow, particularly a position sensor mechanically connected to the handling device (6) or a flow meter ; the output of the sensor means (7) is connected to one input of a comparator (8), whose other input is connected to a desired or reference signal supplying member (9) said comparator (8) supplying a voltage which is a direct function of the difference between the desired value and the real value ; said converter also having a saw tooth generator (10) connected to a threshold detector (11) connected to the output of the comparator (8) and which compares the signal form the saw tooth generator (10) with that from the comparator (8) and supplies a cyclical ration square wave signal, characterised in that the electro-valves (1, 2) have a fast switching frequency of approximately 100 Hz, that a phase shifting circuit (12) is provided for each electro-valve (2), excepting the first electro-valve, the inputs of these first electronic control means of the first electro-valve (1) and the phase shifting circuits (12) being connected to the output of the threshold detector (11) by a common connection point (C) and that the electronic control means (3, 4) allocated to the electro-valves (1, 2) have, at the electro-valve cut-off supply, a shift equal to 2 pi/n, n representing the number of electro-valves used. |
