| 摘要 |
An attachment to a traffic light apparatus for indicating duration of a current traffic light signal comprises a panel that consists of a plurality of lamps which are electrically connected in parallel to a source of power supply and are controlled by a clock signal from the traffic light apparatus via a central processing unit and a controller. Each lamp is connected to the power supply line via an individual relay, the contacts of which are opened and closed under control of commands from the aforementioned central processing unit via the controller. The indication panel is divided into a plurality of color cells. Each cell contains a lamp. On the oncoming traffic side each cell is closed with a transparent color plate that defines the color of the light with which the cell is illuminated when the lamp is lit. The color cells may have different arrangements such as an alternating order in each row or the same color of cells in each row with alternation of vertical or horizontal rows. When a green light signal is switched on, at the initial moments green lamps are lit in all the cells. With the laps of time, however, the green lamps are switched off in a stepwise manner, e.g., from the top to the bottom of the indication panel, so that a viewer sees a gradually decreased rectangular green image.
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