. Archives of physical medicine and rehabilitation . volt, thepower is I volt-ampere or I watt. (746watts equal I horsepower.) If 50amperes flow under a potential differ-ence of 1 1 0 volts, the power is 50\110 or 5500 watts. An electrictoaster consuming 550 watts when op-erated on I I 0 volts has a current of 5amperes flowing through it. When,therefore, the voltage used to drive 10milliamperes through an x-ray tube is20,000 volts, the power supplied thetube is proportional to 10 1000 V20,000 or 200 watts. The productdoes not give the exact value of thepower in watts because although thecurren
. Archives of physical medicine and rehabilitation . volt, thepower is I volt-ampere or I watt. (746watts equal I horsepower.) If 50amperes flow under a potential differ-ence of 1 1 0 volts, the power is 50\110 or 5500 watts. An electrictoaster consuming 550 watts when op-erated on I I 0 volts has a current of 5amperes flowing through it. When,therefore, the voltage used to drive 10milliamperes through an x-ray tube is20,000 volts, the power supplied thetube is proportional to 10 1000 V20,000 or 200 watts. The productdoes not give the exact value of thepower in watts because although thecurrent may be the correct averagevalue, the voltage value in general isnot the average, but probably the max-imum (crest) value during a half speaking, however, rve ma])compare the amounts of energv sup-plied a tube each second under differ-ent condit ons h^ comparing the prod-ucts of the effective crest voltage be-tUeen its terminals times the currentflowing through it. Now the so-called capacity of anoutfit refers to the maximum energy. F/G. 30 114 per second it is capable of supplyinx-iay tube. (The word capacity isnot a very happy one, as in electricalscience capacity has a very definite anddistinctly different meaning. SeeSection 33.) It is usually expressedby giving the value of the maximumcunent which can be supplied a tube,under a specified back-up. For ex-ample, in advertising literature one findsstatements such as the following: Acertan unit is capable of energizingthe 30 ma. 5-inch Coolidge Tube; theoutput of another is rated at 250 a 6-inch back-up between statements do not mean that thetransformer may not be able to maintaina much higher voltage across a tubethon the one stated. For example, inconnection with the second of these out-fits, the catalogue states further thatthe maximum spark gap betweenpoints is 12 inches. Should highervoltages (than those corresponding toa 6-inch gap) be utilized, a corre-spondingly smaller current would
Size: 1771px × 1411px
Photo credit: © Reading Room 2020 / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookauthoramerican, bookcentury1900, bookdecade1920, bookyear1920
