| 摘要 |
<p>1,239,065. Pure fluid analogue circuits. GENERAL ELECTRIC CO. Nov. 19, 1968 [Nov.29, 1967], No.54813/68. Heading G3H. A pure fluid analogue circuit produces an output pressure which is inversely proportional to the frequency of an oscillating input signal. The circuit comprises a digital amplifier 6 which shapes the random signal #P i to a square wave form signal #P 1 , a proportional amplifier 13 fed with signal #P 1 , and having an inductance 16 connected across its outputs 14, 15 to produce a modified signal #P 2 which is fed to an amplifier 17 which acts as a full wave rectifier producing a signal P o having an average amplitude inversely proportional to the average amplitude of signal #P 2 . Signal P o is fed through a resistor 19 and capacitance 20 to one control orifice of a final proportional amplifier 21 which has a variable bias control 22 and which produces an output pressure #P 0 which varies inversely with the frequency of signal #P i . In a modification Fig.2 (not shown) the centre point of inductance 16 is vented to atmosphere. In another modification (not shown) amplifier 13 is dispensed with. The specification sets out optimum dimensions for the circuit elements and states that they can be built into an integrated circuit.</p> |
