| 摘要 |
An electronic lighting device for simulating a flame, particularly a candle flame. In the preferred embodiment a set of three vertically spaced lamps are enclosed in a translucent bulb and are controlled by a signal generator circuit which independently turns three lamps on and off in a manner which simulates both the illumination distribution and the gas turbulence in a natural flame. The circuit includes a multistage static shift register which is used in a feedback mode to produce three mutually delayed pseudo-random pulse trains. One pulse train is used directly to control the uppermost lamp. The other pulse trains are combined with assymetric long-duty-cycle and short-duty-cycle clock signals. The resulting combined signals are used to drive the lower and middle lamps, respectively. The net result is that the lowermost lamp is brightest and flickers only dimly; the middle lamp is of intermediate brightness and appears to flicker more distinctly; and the upper lamp is on half the time and off half the time, on average, with the average brightness being less than either of the lower lamps and the flickering effect being more pronounced than that of either the lower or middle lamps.
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