An apparatus for controlling power consumption of a light source in a mobile projector, comprising: a power calculation unit (41, 61) arranged to calculate power consumption of the light source; and a current adjustment unit (42, 62) arranged to compare the power calculated by the power calculation unit with a preset power value (W0, WATT_SET) and to automatically adjust a current flowing to the light source according to the comparison, wherein the light source comprises Red, Green, and Blue, RGB, LEDs, and wherein the current adjustment unit (42, 62) further comprises: a comparator arranged to calculate a difference (ΔW=W-W0) between the preset power value (W0, WATT SET) and a total power consumption of the light source; a dimming unit arranged to time-sequentially output values corresponding to the respective RGB LEDs to adjust respective currents of the RGB LEDs by adding/subtracting the difference calculated by the comparator to/from preset current values of the respective RGB LEDs to output resultant values, and outputting the resultant values corresponding to the respective RGB LEDs to maintain a ratio of the preset current values (RSET, GSET, BSET) of the respective RGB LEDs; and a switching unit arranged to receive the output values of the dimming unit, to change the voltages output to the respective RGB LEDs according to the output values, and to time-sequentially adjust the voltages output to maintain the total power consumption as the preset power value. a power calculation unit (41, 61) arranged to calculate power consumption of the light source; and a current adjustment unit (42, 62) arranged to compare the power calculated by the power calculation unit with a preset power value (W0, WATT_SET) and to automatically adjust a current flowing to the light source according to the comparison, wherein the light source comprises Red, Green, and Blue, RGB, LEDs, and wherein the current adjustment unit (42, 62) further comprises: a comparator arranged to calculate a difference (ΔW=W-W0) between the preset power value (W0, WATT SET) and a total power consumption of the light source; a dimming unit arranged to time-sequentially output values corresponding to the respective RGB LEDs to adjust respective currents of the RGB LEDs by adding/subtracting the difference calculated by the comparator to/from preset current values of the respective RGB LEDs to output resultant values, and outputting the resultant values corresponding to the respective RGB LEDs to maintain a ratio of the preset current values (RSET, GSET, BSET) of the respective RGB LEDs; and a switching unit arranged to receive the output values of the dimming unit, to change the voltages output to the respective RGB LEDs according to the output values, and to time-sequentially adjust the voltages output to maintain the total power consumption as the preset power value. a comparator arranged to calculate a difference (ΔW=W-W0) between the preset power value (W0, WATT SET) and a total power consumption of the light source; a dimming unit arranged to time-sequentially output values corresponding to the respective RGB LEDs to adjust respective currents of the RGB LEDs by adding/subtracting the difference calculated by the comparator to/from preset current values of the respective RGB LEDs to output resultant values, and outputting the resultant values corresponding to the respective RGB LEDs to maintain a ratio of the preset current values (RSET, GSET, BSET) of the respective RGB LEDs; and a switching unit arranged to receive the output values of the dimming unit, to change the voltages output to the respective RGB LEDs according to the output values, and to time-sequentially adjust the voltages output to maintain the total power consumption as the preset power value.