JPS6466694A - Fluorescent display device - Google Patents

Abstract

PURPOSE: To drive so as to rapidly start the display of a fluorescent display tube with a power source application by inputting the output of an oscillating circuit starting operation with turning-on of a power source switch into a transformer and switching the output of the transformer to a high and low voltage side. CONSTITUTION: When a key switch 6 is put turned on, the oscillating circuit 1 starts oscillation, the high and low voltage are respectively made to appear in taps 21 and 22 of a secondary side coil 2b of the transformer 2. Although the charge to a capacitor 42 is started with turning-on of the key switch 6 in a timer circuit 4, a transistor 43 is not operated for a short time before the charge voltage rises up to a given level, therefore a contact between C1 and C2 is closed in a relay 3. By this way, filament 5 is rapidly heated with the application of the high voltage, the fluorescent tube is allowed to display in a short time after the key switch is put turned on. When the charge voltage to the capacitor 42 exceeds a given level, the transistor 43 is operated, and the contact between C1 and C2 is closed in the relay 3.