| 摘要 |
An electronic transformer for driving a load (L) from a mains signal comprises an ignition capacitor (Cs), an input stage (10) for loading the ignition capacitor (Cs) from the mains signal, and a switching output stage (12) for driving the load (L). The output stage (12) is switcheable (Ta, Tb) as a function of the charge loaded on said ignition capacitor (Cs), and a charge amplifier stage (18) is interposed between the ignition capacitor (Cs) and the switching output stage (12). A loading resistor (Rs) is coupled with the ignition capacitor (Cs) for loading the ignition capacitor (Cs) from said mains signal, and a controllable (14) switch (Td) permits to selectively short-circuit the ignition capacitor (Cs) and put the electronic transformer at standby. The presence of the charge amplifier stage (18) permits to reduce the capacitance value of the ignition capacitor (Cs) and to increase the value of the loading resistor (Rs), thereby reducing power absorption at standby. |
