Electrically detected magnetic resonance (EDMR) measurements of bulk silicon carbide (SiC) crystals, which have wide band-gaps, were conducted. A high-power ultraviolet light-emitting diode was used as a low-noise light source to excite excessive carriers. Under light irradiation, EDMR spectra of a 4H-SiC wafer (8-mm wide, 8-mm long) at an ESR frequency of 900 MHz was obtained with a g-value of 2.000 +/-0.003, indicating that the major recombination center was a vacancy. EDMR spectra were observed at all detection phases of magnetic field modulation. The spectrum observed at in-phase (0 degrees) was a single line; at out-of-phase (90 degrees), the different spectrum was observed.