Wheatstone bridge with compensation for a temperature gradient between the main resistances of the bridge and application thereof in a pressure sensor having strain gauges

摘要

PCT No. PCT/FR96/01933 Sec. 371 Date Jun. 3, 1998 Sec. 102(e) Date Jun. 3, 1998 PCT Filed Dec. 4, 1996 PCT Pub. No. WO97/21083 PCT Pub. Date Jun. 12, 1997The output voltage of a Wheatstone bridge type electrical circuit comprising four main resistances (J1 to J4) having substantially the same ohmic value, R, and substantially the same temperature coefficient of resistance, alpha , is made independent of temperature differences existing between the branches of the bridge by addition, in each of the branches, of a compensation element (r1 to r4) in series with the main resistance, each compensation element being physically located very close to a main resistance situated in one of the adjacent branches of the bridge so as to have the same temperature as that main resistance. The compensation elements have the same ohmic value r and the same temperature coefficient of resistance beta , with R alpha =r beta , r being less than R and, preferably, r/R