| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a flow detection device capable of reducing detection errors by suppressing each temperature change of a resistor for setting the conversion rate and a capacitor for conversion. <P>SOLUTION: This flow detection device 10 is constituted of a bridge circuit 11, a V/F conversion circuit 19, or the like. In the V/F conversion circuit 19, an analog signal outputted from the bridge circuit 11 is converted into a current, and a capacitor 18 is charged by the current. Meanwhile, the capacitor 18 is discharged, each time a charge voltage of the capacitor 18 reaches a prescribed voltage. The V/F conversion circuit 19 outputs a digital signal, having a frequency corresponding to the analog signal based on the charge voltage of the capacitor 18. Here, the conversion rate of V/I conversion is set by the resistance value of the resistor 17, and the resistor 17 and the capacitor 18 are mounted separately, as long as a heat mitigation domain portion for mitigating heat transfer from a power transistor TR1 on a ceramic substrate 22 on which the bridge circuit 11 and the V/F conversion circuit 19 are mounted. <P>COPYRIGHT: (C)2009,JPO&INPIT</p> |
