Interpretation ID: nht93-3.20

DATE: April 26, 1993

FROM: John Womack -- Acting Chief Counsel, U.S. Department of Transportation, NHTSA

TO: T. Kouchi -- Director, Stanley Electric Co., Ltd.

TITLE: None

ATTACHMT: Attached to letter dated 4-2-93 from T. Kouchi to Paul Jackson Rice

TEXT: This responds to your letter of April 2, 1993, to Paul Jackson Rice, the former Chief Counsel of this agency.

You refer to Mr. Rice's letter of December 30, 1992, which you interpret as saying that "any device that contains more than three lighted sections, or LEDs, need only comply with the requirements prescribed for three lighted sections." You consider "that the lamps having three lighted sections described in the attached drawing No. 1 & No. 2 need only comply with the photometric requirements prescribed for three lighted sections." You ask "if our idea is appropriate."

We confirm your interpretation with respect to drawing No. 1, which appears essentially the same as covered by Mr. Rice's interpretation. With respect to drawing No. 2, this lamp appears to be composed of a panel of LEDs flanked by two incandescent bulbs. When the LED panel alone is operated, or when it is operated in conjunction with either one or both of the incandescent bulbs the requirements applicable to three lighted sections will apply. However, each bulb is regarded as being a single light source so that if the bulbs are operated individually, only the requirements for single lighted sections apply.

If the bulbs are operated simultaneously to perform the same function, the requirements for two lighted sections apply. However, if the bulbs are operated simultaneously to perform different functions, the single lighted section requirements apply and all other requirements such as contrast ratios (e.g., the 1:5 for tail and stop lamps) must be met.