| 摘要 |
PURPOSE:To constitute the titled device so that no noise is generated even if a thyristor control is executed, by controlling an electric conduction time by setting one period of an AC waveform as the minimum unit in accordance with a control element. CONSTITUTION:In an AC power control device for heating the glass in order to eliminate a cloud or an ice-drop, etc. adhering to the glass due to a difference between a room temperature and an open air temperature, a means for executing an electric conduction control by setting one period of an AC waveform as the minimum unit, and a means for determining an electric conduction period of the AC waveform in accordance with a control element are provided. For instance, a filter circuit 1 prevents an invasion of a noise from the outside, and a leakage of the noise to the outside from this device, and a power source circuit 2 converts an AC voltage to a DC voltage required for an operation of this device. A heater electric conduction time control circuit 4 adds a temperature of a window-pane, and an elapsed time from the time when a power source has been turned on, to a current supplied to a heater, and executes an electric conduction time control by setting one period of the AC waveform as the minimum unit. A gate signal generation time control circuit generates a gate signal required for controlling an electric conduction time extending over open period portion of a thyristor circuit 6. |
