| 摘要 |
<p>914,304. Measuring electrically. COMMISSARIAT A L'ENERGIE ATOMIQUE. Jan. 23, 1961 [Jan. 22, 1960], No. 2581/61. Class 40 (1). An indicator device for fluid-pressure pick-ups includes a stabilized power supply accommodated in a chassis, and an impedancematching device and an indicator unit equipped with a safety device arranged in replaceable drawers which fit into the chassis, both chassis and drawers having means for electrical connection to the elements which they contain. The slider 13 of a potentiometer 12 is secured to a pressure - sensitive member and forms the pick-up 10, which is plugged into a chassis K at 11. Power is supplied to a regulator transformer 1 through switches 3, permitting operation at different voltages, and gives an output voltage stable to within Œ1% for Œ15% variations in input voltage. This voltage is stepped-down at 4, rectified at 5, and further stabilized to better than Œ0.5% by a Zener diode arrangement 6. Drawer L, containing an impedance-matching device for adjusting the sensitivity and zero of the pick-up, fits into the chassis and is electrically connected so that the stabilized voltage is applied across potentiometer 14, through resistors 15, 16, 17. The stabilized voltage is also applied, through resistors 18, 19, across pick-up potentiometer 12. Drawer M contains an indicator 21 which is connected between slider 20 of potentiometer 14 and slider 13 of potentiometer 12, completing a Wheatstone bridge circuit. A safety device which indicates when a predetermined maximum pressure is reached is also included in drawer M and comprises a thyratron 7 having its grid 22 connected to the input to indicator 21. The grid is adjustably biased by potentiometer 23 and on firing actuates relay 24, which causes warning lamp 9 to light and may also operate control devices. A socket 28 is provided for a recording device and a third drawer N containing a regulator appliance may be provided. Switch 26 connects indicator 21 directly to the stabilized power supply for calibration. By replacing drawers L and M the device may be used over different pressure ranges and with pick-ups of different resistance.</p> |
