| 摘要 |
To protect electromagnetic ballasts (2) against damage, driver circuits (1) for coupling the electromagnetic ballasts (2) to light circuits (3) comprising light emitting diodes are provided with rectifier bridges (11-14) for exchanging first current signals with the electromagnetic ballasts (2) and for providing second current signals to the light circuits (3), and with protection circuits (21-24, 25-27) for protecting the electromagnetic ballasts (3) against parameters of the first current signals obtaining values larger than threshold values. The parameters may be direct-current components of the first current signals and may be average values of rectified versions of the first current signals / peak values of the first current signals. The rectifier bridges (11-14) may comprise first diode elements. The protection circuits (21-24, 25-27) may comprise second diode elements serially coupled to the first diode elements. The protection circuit may comprise average value detectors (25) / peak value detectors (26) and may comprise switches (27) for, in response to detection results, interrupting the second current signals. |
