| 摘要 |
PURPOSE:To lower a cost, by avoiding the smoothing capacitor of a chopper, and by using a smoothing choke serving also as the constant current choke of an inverter. CONSTITUTION:A power-supply device is provided with a chopper circuit 2 connected to a pulse width controlling circuit PWM, and a constant current push-pull type inverter 3, and from the secondary winding Ws of an output transformer T1, current is fed to a fluorescent lamp FL for a load. Then, a chopper switching element Qcp, a choke (inductor) Lcp, and said inverter 3 are connected in series. By the choke Lcp, the inverter 3 is constant-current-push-pull- formed, and ON/OFF-output from the chopper 2 is smoothed by the choke Lcp, and continuous DC output is fed to the inverter 3, and so the choke Lcp is worked also for smoothing the chopper 2. |
