| 摘要 |
1,274,329. Measuring temperature electrically. BARMAG BARMER MASCHINENFABRIK A.G. Dec. 18, 1969 [Dec. 24, 1968], No.61665/69. Heading G1N. Apparatus for transmitting a voltage representative of temperature from a rotatable body when it is at rest comprises four stationary induction coils 30, 31, 32, 33 arranged to receive signals from two induction coils 22, 23 mounted on a rotatable plate 21 the arcuate spacing between opposed faces e.g. 30<SP>1</SP>, 31<SP>1</SP> of the stationary coils being greater than that between opposed ends 24, 25 of the rotatable coils so that whatever the relative dispositions of the rotatable and stationary coils there is always at least one stationary coil in effective communication with a rotatable coil even when the plate is stationary. The circuit for deriving signals from the apparatus uses thermistors 13, 14 connected in a Wien-Robinson bridge to provide across rotatable coil 18 an A.C. output signal representative in magnitude and phase of bridge unbalance which signal is coupled to stationary coil 20. The bridge is energized by rotatable coil 17 coupled with stationary coil 19 and includes fixed resistors 15, 16. A coil 30 or 31 and another 32 or 33 is selected by a switch (37, 38) Fig. 5 (not shown) with a relay coil (40) actuated from a photodetector (42) Fig. 5 (not shown) which determines the position of the rotatable coils and selects those rotatable coils in optimum communication with stationary coils. The switch is disabled during rotation of the coils by the output voltage from a tachogenerator (43) which is applied to the amplifier (41) to block it. |
