A trailing edge phase control dimmer circuit for controlling alternating current, AC, power to a load, the circuit including: a switching circuit for controlling delivery of AC power to the load by conducting power to the load in an ON state and not conducting power to the load in an OFF state; and a switching control circuit for controlling a turn-OFF and a turn-ON of the switching circuit at each cycle of the AC to control switching of the ON and OFF states of the switching circuit, wherein the switching control circuit is adapted to control the turn-OFF of the switching circuit by controlling a turn-OFF transition of the switching circuit between the ON state and the OFF state of the switching circuit, the switching control circuit further includes a dv/dt feedback circuit for controlling a turn-OFF transition profile by returning at least some dv/dt feedback current generated by the switching circuit back to the switching circuit, the dv/dt feedback circuit is configured to control said at least some dv/dt feedback current over the turn-OFF transition so as to reduce a rate of change of at least an initial region of the turn-OFF transition profile to minimise harmonics generation by the switching circuit, the switching circuit includes two MOSFETs (Q4, Q5) to control the turn-OFF and the turn-ON at each half cycle of the AC respectively, and wherein the switching control circuit provides gate drive control of the MOSFETs (Q4, Q5) to control the turn-OFF transition of the MOSFETs (Q4, Q5), a turn-OFF transition time is proportional to a discharge time of a MOSFET gate capacitance of the MOSFETs (Q4, Q5), the switching control circuit includes a second transistor configured to be pulled low to cause discharge of the MOSFETs gate capacitance via a third resistor with a selected resistance to select the discharge time of the MOSFET gate capacitance, the dv/dt feedback circuit includes a third transistor to direct said at least some dv/dt feedback current through a first capacitor with a selected capacitance to the gates of the MOSFETs (Q4, Q5) when sufficient voltage across a fourth resistor with a selected resistance occurs in the switching control circuit, characterised in that the switching control circuit includes an RC network connected between the third transistor and the gates of the MOSFETs (Q4, Q5). a switching circuit for controlling delivery of AC power to the load by conducting power to the load in an ON state and not conducting power to the load in an OFF state; and a switching control circuit for controlling a turn-OFF and a turn-ON of the switching circuit at each cycle of the AC to control switching of the ON and OFF states of the switching circuit, wherein the switching control circuit is adapted to control the turn-OFF of the switching circuit by controlling a turn-OFF transition of the switching circuit between the ON state and the OFF state of the switching circuit, the switching control circuit further includes a dv/dt feedback circuit for controlling a turn-OFF transition profile by returning at least some dv/dt feedback current generated by the switching circuit back to the switching circuit, the dv/dt feedback circuit is configured to control said at least some dv/dt feedback current over the turn-OFF transition so as to reduce a rate of change of at least an initial region of the turn-OFF transition profile to minimise harmonics generation by the switching circuit, the switching circuit includes two MOSFETs (Q4, Q5) to control the turn-OFF and the turn-ON at each half cycle of the AC respectively, and wherein the switching control circuit provides gate drive control of the MOSFETs (Q4, Q5) to control the turn-OFF transition of the MOSFETs (Q4, Q5), a turn-OFF transition time is proportional to a discharge time of a MOSFET gate capacitance of the MOSFETs (Q4, Q5), the switching control circuit includes a second transistor configured to be pulled low to cause discharge of the MOSFETs gate capacitance via a third resistor with a selected resistance to select the discharge time of the MOSFET gate capacitance, the dv/dt feedback circuit includes a third transistor to direct said at least some dv/dt feedback current through a first capacitor with a selected capacitance to the gates of the MOSFETs (Q4, Q5) when sufficient voltage across a fourth resistor with a selected resistance occurs in the switching control circuit, characterised in that the switching control circuit includes an RC network connected between the third transistor and the gates of the MOSFETs (Q4, Q5).