| 摘要 |
<p>An illuminated sign (10) has a plurality of series connected light emitting diodes (22) arranged to form a perceivable intelligence and a control circuit (40) to supply power to the series connected diodes and maintain a battery (134) in a charged condition from line power and, during power failures, to supply power to the series connected diodes. The control circuit illuminates the diodes continuously during normal operation and a multivibrator (48) alternately switches the diodes on and off during a power failure.</p> |
