| 摘要 |
<p>PURPOSE:To improve environment resistance such as temperature characteristics and radio wave resisting characteristics highly accurately by integrating a constant-temperature controlling circuit, a zero/span circuit and a voltage- frequency converter circuit on a same semiconductor chip. CONSTITUTION:A hot wire 11 which receives the wind caused by an air flow and detects the flow rate of the wind is connected to the outside of a one chip control circuit 40 and provided in an air flow path wherein the flow rate is to be measured. Driving power is imparted with a transistor 10. A cold wire 12 for measuring the temperature of the air is provided at the outside and arranged in the air path like the hot wire 11. A circuit part as one chip is provided in the control circuit 40. The parts of a constant temperature control circuit 1, a zero/span circuit 2 and voltage controlled oscillator 3 are integrated at this part. In this way, the temperature compensation becomes easy, and the sufficient environment resistance can be readily imparted.</p> |
