| 摘要 |
848,548. Supply systems for discharge lamps. LUMALAMPEN A.B. Dec. 20, 1956 [Dec. 21, 1955], No. 38899/56. Class 38 (4). In a resonant circuit for operating a hot cathode discharge lamp, a transformer 4-6 has its windings closely coupled so that resistance /temperature changes of the heaters 7, 8 cause like changes in potential across the tube 1, thus limiting the voltage to below the striking value when the heaters are cold. A choke 3, capacitor 2, and transformer primary winding 4 are connected in series across an A.C. supply. The secondary windings 5-6 are directly connected to the heaters 7, 8, also across the capacitortransformer combination 2, 4. The parameters of the circuit are arranged, so that initially the voltage across the tube is about 260 volts, i.e. below the striking value, rising to 300 volts with the heaters hot, thus igniting the tube, this voltage then dropping owing to the shunting effect of the discharge current. Constructional details of the components are given, also circuits for series and parallel twin tube circuits. |
