| 摘要 |
A semiconductor pressure detector apparatus has a strain-electric signal conversion bridge which is composed of four semiconductor strain gauges, and an amplifier which serves to hold at a predetermined value the sum of currents flowing through the bridge. The midpoints of two arms constituting the bridge are respectively connected to the noninverting inputs of two negative feedback amplifiers. Outputs from the two negative feedback amplifiers are applied to a differential amplifier, and an output proportional to the difference of the outputs of the former amplifiers appears at an output terminal of the latter amplifier. A potential equal to potentials which appear at the midpoints of the two arms of the bridge when the bridge is in its balanced state at a predetermined temperature and under a predetermined pressure is generated by two resistances which are connected in series with a supply voltage, and the potential is applied through a switch to either of the inverting inputs of the two negative feedback amplifiers, whereby the zero-point temperature compensation of this apparatus is made. |
