POWER-ON SYSTEM

PURPOSE:To stably turn ON and OFF the power source stably almost without being affected by an external noise, etc., by feeding a demagnetizing current or rush current which has a value several times as large as the stationary current consumption value of a display device and disconnecting the power source when there is no current consumption. CONSTITUTION:When the color CRT display device is powered ON, a current detection part 11 detects the current consumption of the display device 2 and sends it to a demagnetizing current discrimination part 12 and a power-OFF discrimination part 13. The demagnetizing current discrimination part 12 once detecting a current several times as large as a stationary consumed current like a demagnetizing current sends its information to a signal holding part 14 and holds it as the power-ON signal of the display device 2. The held signal is sent to a main switch part 15 and a controller 1 is powered ON. The power-OFF discrimination part 13, on the other hand, once detecting the display device 2 being powered OFF, i.e., no current consumption sends its information to the signal holding part 14, which resets the power-ON signal of the display device 2 that is held so far. The main switch part 15 turns OFF the power source of the controller 1 in response to the resetting of the signal from the signal holding part 14.