| 摘要 |
PURPOSE:To prevent the wasteful consumption of power by performing the display opration for a fixed time when display is required. CONSTITUTION:Through capacitor C is changed when power source switch 2 is turned on, the power source voltage is inputted to driving circuit 6 because transistor Tr1 is turned off until this charging advances to a certain degree, and the number of LEDs 8 according to this input voltage is lit to display the power source voltage. Transistor Tr1 is turned on after a fixed time, and all LEDs 8 are extinguished. When the oprator wants to perform display again, switches 4 and 4a are switched to the contact b side and are switched to the contact a side after discharging the charge of capacitor C, and then, LEDs are lit again for a fixed time. |
