| 摘要 |
<p>The fluid flow control system has a rotating flow meter (1) which is fixed in a pipe (2) through which the fluid flows. The flowmeter (1) is controlled by a brake motor (3) which is an electrical step by step motor. This motor is connected by a shaft (4) and an endless screw (5) to a tangent wheel (6) directly coupled to the flow meter (1). Variation of motor speed is achieved by a frequency synthesiser (7) which is controlled by digital data from a central unit such as computer or microprocessor. The synthesiser controls the step by step motor (3) it being connected to the latter by an amplifier (8). The frequency synthesiser is controlled by a variable pilot frequency to which is a function of a magnitude such as a fluid temp., PH value or of colour.</p> |
