Note that not all luminous intensity points in Table 1.1 are
specified. Therefore, the first step in calculating the minimum
luminous flux is to estimate the luminous intensity values for
the unspecified coordinates (e.g., 5L, 5U and 15L, 10U). A
reasonable assumption is that the luminous intensities of the
unspecified points are equal to the average values of the
luminous intensities of the four adjacent points. Using these
assumptions, the minimum luminous intensities of all of the
unspecified points are shown in Table 1.2. Next the zonal
constant integration is calculated by adding the luminous
intensity values in each horizontal band (e.g., 10U, 5U, etc.)
and multiplying by the zonal constant. Finally, the total lumi
nous flux of the signal lamp is simply equal to the sum of the
luminous flux values for each horizontal band. For example,
referring to the 10U row of Table 1.2, the luminous flux
emitted within the horizontal band (from 7.5° to 12.5°) is
equal to:
Φ
V
≅
(1
+
10
+
17
+
24
+
26
+
42
+
26
+
24
⎛
4
π
2
⎞
+
17
+
10
+
1)
⎜
2
⎟
cos (10
°
)
⎝
72
⎠
Φ
V
≅
(1
+
10
+
17
+
24
+
26
+
42
+
26
+
24
+
17
+
10
+
1) (0.00750)
Φ
V
≅
(198) (0.00750)
≅
1.48lm
Table 1.1 Minimum photometric design guidelines for a single compartment amber rear turn signal. All values in the
table are in candela (cd). Note: Maximum luminous intensity at any point is 750 cd.
20 L
10U
5U
H
5D
10D
15
10 L
50
65
5L
26
V
110
5R
26
10R
50
20R
15
130
130
110
130
65
50
15
15
50
26
26
Table 1.2 Zonal constant integration of minimum photometric design guidelines for a single compartment amber
rear turn signal. Note: Parentheses indicate estimated minimum luminous intensity of unspecified points.
25 L
15U
10U
5U
H
5D
10D
15D
(1)
(1)
(2)
(1)
(1)
20 L
(1)
(10)
15
(20)
15
(10)
(1)
15 L
(2)
(17)
(30)
(39)
(30)
(17)
(2)
10 L
(2)
(24)
50
65
50
(24)
(2)
5L
(3)
26
(79)
130
(79)
26
(3)
V
(4)
(42)
110
130
110
(42)
(4)
5R
(3)
26
(79)
130
(79)
26
(3)
10R
(2)
(24)
50
65
50
(24)
(2)
15R
(2)
(17)
(30)
(39)
(30)
(17)
(2)
20R
(1)
(10)
15
(20)
15
(10)
(1)
(1)
(1)
(2)
(1)
(1)
25R
Sum
20
198
460
642
460
198
20
Zonal
Constant
7.36e 3
7.50e 3
7.59e 3
7.62e 3
7.59e 3
7.50e 3
7.36e 3
Total, lm
Flux
lm
0.15
1.48
3.49
4.89
3.49
1.48
0.15
15.13
Using a similar approach, zonal constant integrations for
most commonly used automotive signal lamps were calcu
lated and are shown in Tables 1.3 and 1.4. The minimum
luminous flux requirements for U.S. signal lamps are shown
in Table 1.3. The minimum luminous flux requirements for
European signal lamps are shown in Table 1.4. The values
shown are based on the minimum photometric guidelines for
single compartment lamps.
The specifications for U.S. motor vehicle signal lamps are
written by the Society of Automotive Engineers (SAE). These
publications are published in SAE publication HS 34 titled
SAE Ground Vehicle Lighting Standards Manual,
which is
updated annually. The primary signal lamp specifications for
passenger cars are as follows:
Parking Lamps (Front Position Lamps)
Tail Lamps (Rear Position Lamps) For Use
on Motor Vehicles Less Than 2032 mm in
Overall Width
SAE J586
Stop Lamps for Use on Motor Vehicles Less
Than 2032 mm in Overall Width
SAE J588
Turn Signal Lamps for Use on Motor Vehicles
Less Than 2032 mm in Overall Width
SAE J592
Clearance, Side Marker, and Identification Lamps
SAE J914
Side Turn Signal Lamps for Vehicles Less Than
12 m in Length
SAE J1319
Fog Tail Lamp (Rear Fog Light) Systems
SAE J1957
Center High Mounted Stop Lamp Standard for
Vehicles Less Than 2032 mm in Overall Width
SAE J2087
Daytime Running Lamps For Use on Motor
Vehicles
7
SAE J222
SAE J585
SuperFlux LEDs in Automotive Application Brief AB20 1 (5/04)
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