| 摘要 |
A method of operating a magnetically operated display unit that includes a frame of a color, a plate pivotably mounted on the frame which includes a first surface of a color different from that of the frame and a second surface of a color identical to that of the frame, a magnet embedded in the plate, a U-shaped ferromagnetic element mounted on the frame so that two tips of the magnet are located between two tips of the U-shaped ferromagnetic element, a solenoid mounted on the U-shaped ferromagnetic element and a light emitting diode mounted on the frame. The plate contains a cutout designed for receiving the light emitting diode and one of the tips of the U-shaped ferromagnetic element. The tip of the light emitting diode is located on a level between the plate and the tips of the U-shaped ferromagnetic element. The light emitting diode is visible sufficiently above the surface of the plate so that its light can shine on that surface. In the method of operation, two opposite currents are selectively directed through the solenoid to pivot the plate between opposite positions revealing its different colored sides and revealing or concealing the light emitting diode.
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