| 摘要 |
<p>To allow an electronic ballast (3) of a fluorescent tube lamp or a similar lamp to be replaced by a light emitting diode circuit (2) without removing the electronic ballast (3) a driver (1) is provided with a first circuit (10) for detuning a resonant tank of the electronic ballast (3). The first circuit (10) comprises a serial connection of a capacitor (11) and a bidirectional switch (12). The serial connection is coupled to the electronic ballast (3) for receiving an alternating current signal. The driver (1) is provided with a second circuit (20) for providing a direct current signal to the light emitting diode circuit (2). The second circuit (20) comprises a rectifier with inputs coupled to the serial connection and with outputs coupled to the light emitting diode circuit (2). Further the driver (1) is provided with a third circuit (30) for providing a control signal to the first circuit (10) for controlling an amount of power supplied to the light emitting diode circuit (2).</p> |
