1. A system controller for regulating one or more currents, the system controller comprising:a thermal detector configured to detect a temperature associated with the system controller and generate a thermal detection signal based at least in part on the detected temperature; and
a drive signal generator configured to receive the thermal detection signal and generate a drive signal based at least in part on the thermal detection signal to close or open a switch to affect a drive current associated with one or more light emitting diodes;
wherein the drive signal generator is further configured to:
in response to the detected temperature increasing from a first temperature threshold but remaining smaller than a second temperature threshold, generate the drive signal to keep the drive current at a first current magnitude, the second temperature threshold being higher than the first temperature threshold and the first current magnitude being kept constant between the first temperature threshold and the second temperature threshold; and
in response to the detected temperature increasing to become equal to or larger than the second temperature threshold, change the drive signal to reduce the drive current from the first current magnitude to a second current magnitude, the second current magnitude being smaller than the first current magnitude.