| 摘要 |
PROBLEM TO BE SOLVED: To realize long term continuous use friendly to environment, using a solar battery, over 10 years, while restraining consumption of a primary battery. SOLUTION: A temperature sensor 1 is connected to a main body portion 32 having a display screen 7, a display circuit 8, an electric power source 10 and a temperature measuring circuit 5 to constitute a digital thermometer 30. The temperature measuring circuit 5 processes a signal from the temperature sensor 1 to transmit information to the display circuit 8. A signal from the temperature measuring circuit 5 is processed in the display circuit 5 to display temperature information and other information on the display screen 7. The power source circuit 10 supplies a current to the display circuit 8 and the temperature measuring circuit 5, and has a switching circuit 20 for conducting switching between a current supplied from the solar battery 11 and a current supplied from the primary battery 15 to be adopted selectively. The supply of the current from the primary battery 15 is turned on in the switching circuit 20, when the current from the solar battery 11 gets to a set voltage (1.4V) or less, and the supply of the current from the primary battery 15 is turned off to be supplied from the solar battery 11, in the case other than that. COPYRIGHT: (C)2006,JPO&NCIPI
|
