| 摘要 |
A long life, low maintenance and low energy consumption-lighting device (15) for connection with an electrical socket within a housing of an exit sign comprises a string (35, 35, 60) of series connected light emitting diodes (38) connected in a circuit comprising a capacitor (55) for limiting the current flow through the light emitting diodes (38) and a resistor (40) to limit the surge current through the light emitting diodes (38). The resistor (40), capacitor (55) and light emitting diodes (38) are connected to the socket by one of several different standard light bulb bases (20), and are housed within a hollow translucent or transparent tube connected to the base (20). A surge suppression device (59), such as a TRANSZORB, may be connected in parallel with the resistor (40), capacitor (55) and light emitting diodes (38) to provide line transient protection for protecting the light emitting diodes (38) in response to transient voltage spikes. The lighting device (15) may be provided with a pair of series connected light emitting diode strings (35, 36) connected in parallel with one another, the diodes (38) in one string (35) being connected in opposite polarity to the diodes (38) in the other string (36). Additionally, the light emitting diodes (38) may be either discrete light emitting diodes (38) or die-on type light emitting diodes (100) mounted on one or both sides of a printed circuit board (105).
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