| 摘要 |
<p>PURPOSE:To detect even a slight wind velocity with good sensitivity by connecting four thermistors in a bridge form, covering said thermistors mounted opposite side respectively with a wind preventing hood to generate a self-heat or providing a heater to heat said thermistors. CONSTITUTION:To thermistors Th1-Th4 of the same characteristic and rating, resistors r1, r2 are added for the current adjustment to construct a bridge circuit and the power source voltage is applied to generate self-heat. For the thermistors Th2, Th3 at the opposing sides of the bridge, the wind preventing hood is provided. Even if wind exists, wind does not face as the thermistors Th2, Th3 have a wind preventing hood, but the thermistors Th1, Th4 are faced by wind to be cooled, so that the resistance value of the thermistors becomes large, and the current flows through the transistors Tr1, Tr2 and the detectng output from the output teminal C is obtained. Instead of providing the wind preventing hood, the heater resistor allowed to dispose in the vicinity of the thermistor.</p> |
