A power conversion and control system suitable for use with solid-state lighting and conventional TRIAC dimmer switching includes an alternating current to direct current (AC-DC) converter configured to convert AC power from the AC mains to DC power and a controller configured to control dimming of a light-emitting load depending on the magnitude of a distorted AC voltage from an external TRIAC dimmer switch relative to the magnitude of the DC voltage Vdc produced by the AC-DC converter. To prevent the TRIAC in the external TRIAC dimmer switch from turning off in situations where the AC-DC converter is disconnected from the AC mains or not drawing any current from the AC mains, the power conversion and control system may further include circuitry that maintains the current through the TRIAC above its minimum holding current.