| 摘要 |
PURPOSE:To accurately detect snow, by preventing the deposition of snow by arranging a heater in close vicinity to one solar cell and comparing the outputs of a pair of solar cells. CONSTITUTION:The outputs of a pair of solar cells 2, 3 are equal under the same condition. A heater 4 is arranged in close vicinity to one solar cell 2 and always heated by the supply of a current from an external power source and the output the solar cell 2 is kept so far as there is solar radiation by snow melting even if snow falls to the solar cell 2. The outputs of the solar cells 2, 3 are compared by a comparator 5 and, if there is output difference, a snow detection signal is outputted to turn a relay switch ON and a contact 6a is closed and a snow melting heater or a snow melting means 7 such as a water sprinkler is operated. |
