| 摘要 |
PURPOSE:To miniaturize a lighting circuit board and reduce the cost by forming additional functions into modules, and standardizing the board. CONSTITUTION:When the power voltage is applied to a PWMIC 1 and an on/off control circuit 5 is turned on, the operation is started to control a chopper transistor 2 so that the output set by a dimming control resistor 4 is attained, and the output voltage is stabilized. A module board 21 mounted with part items on both faces is fixed by solder 23 on a main board 24 mounted with part items via metal pins 22 at end sections of the board. Part or all of additional functions separate from the portion of the lighting function of a fluorescent lamp 12 are formed into modules in a modular section 10, and the board 21 is standardized. The additional functions are the dimming function, overcurrent detecting function, DC/DC converter function, on/off function, and power control function. The standardized board 21 is overlapped on the board 24, thus the board 24 is miniaturized, and the cost is reduced. |
