WAH WANG HOLDINGS (HONG KONG) CO., LTD.
Factory
: WAH WANG OPTOELECTRONIC (SHENZHEN) CO LTD;
Wah Wang Data Sheet for 1W Power LED
(Care should be take to the heat release matter when using this High Power LED)
Color
Part No:
Warm White
WW-T503TH0-W2U
批准
审核
制定
牛焕东
梁华彪
林镇心
Tel
Fax
Web Site
: Unit 01, 19th Floor, Nanyang Plaza,
No.57 Hung To Road, Kwun Tong,
Kowloon, Hong Kong
: 852-2512 9939 (10 line)
: 852-2344 2398
: www.wahwang.com
S.D.N. or D.N. No.
:
Customer Name
:
Sample Approval Signature
:
Date
:
Address
1W Power LED Series
Version 3.0
Page 1 of 15
WAH WANG HOLDINGS (HONG KONG) CO., LTD.
Factory
: WAH WANG OPTOELECTRONIC (SHENZHEN) CO LTD;
Wah Wang High Power One Watt Series
Features
Super high Flux output
and high Luminance
Technical Datasheet
• Very long operating life
(up to
50k hours
High Power One Watt LED series is designed for high
• Designed for high
current operation and high flux output applications.
current operation
Furthermore, its thermal management characteristic is
•
Low
thermal resistance
better than other LED Solutions. By package SMD
• SMT solders ability
design and good thermal emission material.
• Lead Free product
• RoHS compliant
According to these advantages, it enables to apply various lighting
applications and design solution, automotive lighting, and large size LCD • No UV
•• Superior ESD protection
backlight etc.
•
Application
• Mobile phone flash
• Automotive interior /
exterior lighting
• Automotive signal lighting
• Automotive forward
lighting
• General Torch
• Architectural lighting
• LCD TV / Monitor Backlight
• Projector light source
• Traffic signals
• Task lighting
• Decorative / Pathway
lighting
• Remote / Solar powered
lighting
• Household appliances
1W Power LED Series
Version 3.0
Page 2 of 15
WAH WANG HOLDINGS (HONG KONG) CO., LTD.
Factory
: WAH WANG OPTOELECTRONIC (SHENZHEN) CO LTD;
Outline Dimensions
Dome Type
Notes:
1. All dimensions are in millimeter.
2. The anode side of the device is denoted by a hole in the lead frame. Electrical insulation between
the case and the board is required-slug of device is not electrically neutral. Do not electrically
connect either the anode or cathode to the slug.
3. All dimensions without tolerances are for reference only.
4. Caution must be used in handing this device to avoid damage to the lens surfaces that will reduce
optical efficiency.
1W Power LED Series
Version 3.0
Page 3 of 15
WAH WANG HOLDINGS (HONG KONG) CO., LTD.
Factory
: WAH WANG OPTOELECTRONIC (SHENZHEN) CO LTD;
Soldering
Pre-heat
Pre-heat time
Peak temperature
Soldering time
Condition
Reflow Soldering
Lead Solder
120~150℃
120sec. Max.
240℃ Max.
10sec. Max.
refer to
Temperatureprofile 1
Hand Soldering
Lead – free Solder
180~200℃
120sec. Max.
260℃ Max.
10sec. Max.
refer to
Temperatureprofile 2
Temperature
Soldering time
300℃ Max.
3sec. Max.
(one time only)
After reflow soldering rapid cooling should be avoided.
[Temperature-profile (Surface of circuit board)] Use the conditions shown to the under figure.
＜1 : Lead Solder＞
＜2 : Lead-free Solder＞
240°C Max.
10sec. Max.
2.5~5°C/sec.
Pre-heating
120~150°C
60sec. Max.
120sec. Max.
2.5~5°C/sec.
260°C Max.
10sec. Max.
1~5°C/sec.
Pre-heating
180~200°C
60sec. Max.
120sec. Max.
1~5°C/sec.
* Caution *
No second soldering recommended
1W Power LED Series
Version 3.0
Page 4 of 15
WAH WANG HOLDINGS (HONG KONG) CO., LTD.
Factory
: WAH WANG OPTOELECTRONIC (SHENZHEN) CO LTD;
Characteristics for 1W Warm White Power LED
Electro-Optical characteristics at IF=350mA, TA=25ºC
PART NO.
WW-T503TH0-W2U
PK1-3/PL1-3
Colour rank
Parameter
Symbol
Luminous Flux (350mA)
Φv
Min
120
Correlated Color Temperature
CCT
CRI
Value
Typ
Unit
-
Max
140
-
3000
-
K
Ra
68
73
-
-
Forward Voltage
VF
2.8
-
3.6
V
View Angle
2Θ1/2
Absolute Maximum Ratings
Parameter
Lm
120
deg.
Symbol
Value
Unit
Continuous Forward Current
IF
350
mA
Peak Forward Current
IFP
500
mA
Reverse Voltage
VR
5
V
Power Dissipation
PD
1200
mW
Junction Temperature
Tj
125
℃
Operating Temperature
Topr
-25~+85
℃
Storage Temperature
Tstg
-40~+100
℃
*Notes:
[1] WW maintains a tolerance of ±10% on flux and power measurements.
[2] CCT ±5% tester tolerance and d ±1nm.
[3] X, Y co-ordinates maintain a tolerance of ±0.01.
[4] A tolerance of ±0.1V on forward voltage measurements
[5] View Angle maintains a tolerance of ±20°
* Caution
1. Please do not drive at rated current more than 5 sec. without proper heat sink
White color spectrum, TA=25ºC
1W Power LED Series
Version 3.0
Page 5 of 15
WAH WANG HOLDINGS (HONG KONG) CO., LTD.
Factory
: WAH WANG OPTOELECTRONIC (SHENZHEN) CO LTD;
Typical Optical/Electrical Characteristics Curves (Ta=25℃ Unless Otherwise Noted
)
<Figure 1:Forward Voltage vs. Forward Current, TA=25℃
450
400
电流(mA)
350
300
250
200
0
Forward
Voltage (V)
2.8
3.0
3.2
3.4
3.6
<Figure 2: Operating current & ambient temperature>
Operating Current vs Ambient Temperature
400
电流(mA)
350
300
250
200
150
100
0
0
20
40
60
6
80
100
120
0
Ambient
Temperature (°C)
140
160
16
0
<Figure 3. Forward current & relative luminous at Ta=25℃
160
Luminous Flux vs Operating Current
发光强度
140
120
100
80
60
40
20
0
Forward Current
(mA)
电流(mA)
1W Power LED Series
200
250
300
Version 3.0
350
400
Page 6 of 15
WAH WANG HOLDINGS (HONG KONG) CO., LTD.
Factory
: WAH WANG OPTOELECTRONIC (SHENZHEN) CO LTD;
<Figure 4：Forward Current VS Chromaticity Coordinate:TA=25℃ (Pure white)
Product Packaging Information
BIN CODE:***—**
1
2
**3 **
4
1：Order Rank
2：IV Rank (sheet 1)
3：Colour rank or Dominant wavelength rank (sheet 2)
4: VF rank (sheet 3)
1W Power LED Series
Version 3.0
Page 7 of 15
WAH WANG HOLDINGS (HONG KONG) CO., LTD.
Factory
: WAH WANG OPTOELECTRONIC (SHENZHEN) CO LTD;
Bin Code Definition for delivery
Sheet 1
BIN CODE
01
02
03
04
05
06
07
08
09
∮ VF (lm)
3-6
6-9
9-12
12-16
16-21
21-27
27-36
36-46
46-60
Class
A
C
J
K
L
E
F
H
M
BIN CODE
10
11
12
13
14
15
16
17
18
19
∮ VF (lm)
60-70
70-80
80-90
90-100
100-120
120-170
170-220
220-280
280-360
360-470
Class
D
B
Q
T
U
N
O
P
R
S
Sheet 2
1W Power LED Series
Version 3.0
Page 8 of 15
WAH WANG HOLDINGS (HONG KONG) CO., LTD.
Factory
BIN
PO1
PO2
PO3
PN1
PN2
PN3
PM1
PM2
PM3
PL1
PL2
PL3
PH4
: WAH WANG OPTOELECTRONIC (SHENZHEN) CO LTD;
CHR-X
CHR-Y
0.2827
0.2877
0.2946
0.2903
0.2776
0.2827
0.2903
0.286
0.2726
0.2776
0.286
0.2818
0.2903
0.2946
0.3022
0.2988
0.286
0.2903
0.2988
0.2954
0.2818
0.286
0.2954
0.292
0.2988
0.3022
0.3101
0.3076
0.2954
0.2988
0.3076
0.3051
0.292
0.2954
0.3051
0.3026
0.3076
0.3101
0.3162
0.3144
0.3051
0.3076
0.3144
0.3126
0.3026
0.3051
0.3126
0.3108
0.3481
0.3468
0.3648
0.3676
0.2827
0.2727
0.2808
0.2916
0.2926
0.2827
0.2916
0.3025
0.3026
0.2926
0.3025
0.3133
0.2916
0.2808
0.2892
0.301
0.3025
0.2916
0.301
0.3128
0.3133
0.3025
0.3128
0.3246
0.301
0.2892
0.2975
0.3102
0.3128
0.301
0.3102
0.3229
0.3246
0.3128
0.3229
0.3357
0.3102
0.2975
0.3035
0.3169
0.3229
0.3102
0.3169
0.3303
0.3357
0.3229
0.3303
0.3437
0.3919
0.3758
0.3894
0.4067
1W Power LED Series
TC(K)
BIN
8800-10000
PK1
8800-10000
PK2
8800-10000
PK3
7800-8800
PJ1
7800-8800
PJ2
7800-8800
PJ3
7000-7800
PI1
7000-7800
PI2
7000-7800
PI3
6500-7000
PI4
6500-7000
PH1
6500-7000
PH2
4500-5000
PH3
CHR-X
CHR-Y
0.3144
0.3162
0.3235
0.3225
0.3126
0.3144
0.3225
0.3215
0.3108
0.3126
0.3215
0.3206
0.3225
0.3235
0.3323
0.3323
0.3215
0.3225
0.3323
0.3323
0.3206
0.3215
0.3323
0.3324
0.3323
0.3323
0.3431
0.3443
0.3323
0.3323
0.3443
0.3456
0.3324
0.3323
0.3456
0.3468
0.3324
0.3324
0.3468
0.3481
0.3443
0.3431
0.3565
0.3593
0.3456
0.3443
0.3593
0.362
0.3468
0.3456
0.362
0.3648
0.3169
0.3035
0.3104
0.3246
0.3303
0.3169
0.3246
0.3388
0.3437
0.3303
0.3388
0.353
0.3246
0.3104
0.3183
0.3334
0.3388
0.3246
0.3334
0.3486
0.353
0.3388
0.3486
0.3636
0.3334
0.3183
0.3273
0.3435
0.3486
0.3334
0.3435
0.3596
0.3636
0.3486
0.3596
0.3758
0.3787
0.3636
0.3758
0.3919
0.3435
0.3273
0.3377
0.3549
0.3596
0.3435
0.3549
0.3721
0.3758
0.3596
0.3721
0.3894
Version 3.0
TC(K)
6000-6500
6000-6500
6000-6500
5500-6000
5500-6000
5500-6000
5000-5500
5000-5500
5000-5500
5000-5500
4500-5000
4500-5000
4500-5000
Page 9 of 15
WAH WANG HOLDINGS (HONG KONG) CO., LTD.
Factory
: WAH WANG OPTOELECTRONIC (SHENZHEN) CO LTD;
0.44
3500
0.42
3800
4500
4100
0.4
5000
PF3
PH4
0.36
PH2
0.32
0.32
PE1
PE2
PE3
PF1
PF2
PF3
PF2
PE1
PG2
PF1
PG1
PH1
0.34
BIN
PE2
PG3
0.38
PH3
PE3
0.34
CHR-X
CHR-Y
0.402
0.387
0.382
0.396
0.409
0.392
0.387
0.402
0.417
0.398
0.392
0.409
0.387
0.372
0.369
0.382
0.392
0.376
0.372
0.387
0.398
0.38
0.376
0.392
0.382
0.374
0.358
0.367
0.4
0.391
0.374
0.382
0.42
0.411
0.391
0.4
0.374
0.364
0.35
0.358
0.391
0.382
0.364
0.374
0.411
0.4
0.382
0.391
0.36
TC(K)
0.38
0.4
BIN
3500-3800
PG1
3500-3800
PG2
3500-3800
PG3
3800-4100
PH1
3800-4100
PH2
3800-4100
PH3
PH4
1W Power LED Series
0.42
CHR-X
CHR-Y
0.372
0.359
0.356
0.369
0.376
0.362
0.359
0.372
0.38
0.365
0.362
0.376
0.3443
0.3431
0.3565
0.3593
0.3456
0.3443
0.3593
0.362
0.3468
0.3456
0.362
0.3648
0.3481
0.3468
0.3648
0.3676
0.364
0.356
0.341
0.35
0.382
0.373
0.356
0.364
0.4
0.389
0.373
0.382
0.3435
0.3273
0.3377
0.3549
0.3596
0.3435
0.3549
0.3721
0.3758
0.3596
0.3721
0.3894
0.3919
0.3758
0.3894
0.4067
Version 3.0
0.44
TC(K)
4100-4500
4100-4500
4100-4500
4500-5000
4500-5000
4500-5000
4500-5000
Page 10 of 15
WAH WANG HOLDINGS (HONG KONG) CO., LTD.
Factory
: WAH WANG OPTOELECTRONIC (SHENZHEN) CO LTD;
Sheet 4
BIN
PD4
PD3
PD2
PD1
PC4
PC3
PC2
PC1
CHR-X
CHR-Y
0.435
0.417
0.411
0.427
0.427
0.411
0.405
0.42
0.42
0.405
0.399
0.412
0.412
0.399
0.395
0.407
0.45
0.435
0.427
0.441
0.441
0.427
0.42
0.433
0.433
0.42
0.412
0.426
0.426
0.412
0.407
0.42
0.429
0.42
0.405
0.413
0.413
0.405
0.39
0.398
0.398
0.39
0.375
0.381
0.381
0.375
0.365
0.37
0.436
0.429
0.413
0.419
0.419
0.413
0.398
0.403
0.403
0.398
0.381
0.388
0.388
0.381
0.37
0.375
1W Power LED Series
TC(K)
BIN
3250-3500
PB4
3250-3500
PB3
3250-3500
PB2
3250-3500
PB1
3050-3250
PA4
3050-3250
PA3
3050-3250
PA2
3050-3250
PA1
CHR-X
CHR-Y
0.466
0.45
0.441
0.457
0.457
0.441
0.433
0.449
0.449
0.433
0.426
0.44
0.44
0.426
0.42
0.432
0.482
0.466
0.457
0.472
0.472
0.457
0.449
0.464
0.464
0.449
0.44
0.454
0.454
0.44
0.432
0.446
0.44
0.436
0.419
0.423
0.423
0.419
0.403
0.408
0.408
0.403
0.388
0.392
0.392
0.388
0.375
0.378
0.444
0.44
0.423
0.426
0.426
0.423
0.408
0.412
0.412
0.408
0.392
0.395
0.395
0.392
0.378
0.381
Version 3.0
TC(K)
2800-3050
2800-3050
2800-3050
2800-3050
2650-2800
2650-2800
2650-2800
2650-2800
Page 11 of 15
WAH WANG HOLDINGS (HONG KONG) CO., LTD.
Factory
: WAH WANG OPTOELECTRONIC (SHENZHEN) CO LTD;
Sheet5
BIN CODE
B01
B02
B03
B04
B05
B06
B07
B08
B09
B10
B11
VF(V)
1.8-2.0
2.0-2.2
2.2-2.4
2.4-2.6
2.6-2.8
2.8-3.0
3.0-3.2
3.2-3.4
3.4-3.6
3.6-3.8
3.8-4.0
BIN CODE
B21
B22
B23
B24
B25
B26
B27
B28
B29
B30
B31
VF(V)
5.8-6.0
6.0-6.2
6.2-6.4
6.4-6.6
6.6-6.8
6.8-7.0
7.2-7.2
7.2-7.4
7.4-7.6
7.6-7.8
7.8-8.0
BIN CODE
C01
C02
C03
C04
C05
C06
C07
C08
C09
C10
C11
VF(V)
1.8-2.1
2.1-2.4
2.4-2.7
2.7-3.0
3.0-3.3
3.3-3.6
3.6-3.9
3.9-4.2
4.2-4.5
4.5-4.8
4.8-5.1
BIN CODE
C21
C22
C23
C24
C25
C26
C27
C28
C29
C30
C31
VF(V)
7.8-8.1
8.1-8.4
8.4-8.7
8.7-9.0
9.0-9.3
9.3-9.6
9.6-9.9
9.9-10.2
10.2-10.5
10.5-10.8
10.8-11.1
Remarks:
1. Customer can opt for any color with respective bin above.
2. X/Y refers to the CIE1931 chromaticity diagram;
3. Co-ordinates X, Y have a tolerance of ± 0.01.
Reliability:
1) Test Items and Results:
Standard Test Method
Note
Number of
Damaged
1000hrs
0/22
Ta=-40℃
1000hrs
0/22
Ta=100℃
1000hrs
0/22
1000hrs
0/22
10 cycles
0/22
100 cycles
0/22
2 times
0/22
No.
Test Item
1
Steady State
Operating Life
2
Low Temperature
Storage
JEITA ED-4701
3
High Temperature
Storage
JEITA ED-4701
4
Temperature
Humidity Storage
JEITA ED-4701
Ta=60℃
100 103
RH=90%
5
Thermal Shock
JEITA ED-4701
100 103
Test Conditions
If=350mA
Ta=25℃
200 202
200 201
JEITA ED-4701
300 307
0℃
~ +100℃
5min~ 15sec ~ 5min
H：+100℃ 30min.
6
Temperature Cycle
JEITA ED-4701
100 105
∫ : +25℃ 5min.
L：－40℃ 30min
JEITA ED-4701
7
Solder Heat
300 301
Tsld=260℃, 10sec
(Max.)
Failed Conditions
Item
Symbol
Test Condition
Min.
Max.
Forward Voltage
VF
IF =350mA
--
*U.S.L×1.1
Reverse Current
IR
VR =5V
--
*U.S.L×2.0
Luminous Intensity
IV
IF =350mA
**L.S.L×0.7
--
1W Power LED Series
Version 3.0
Page 12 of 15
WAH WANG HOLDINGS (HONG KONG) CO., LTD.
Factory
: WAH WANG OPTOELECTRONIC (SHENZHEN) CO LTD;
*U.S.L.: Upper Standard Level
** L.S.L.: Lower Standard Level
Bin Range
Luminous intensity
Bin Code
T
Min. (lm)
90
Max. (lm)
100
U
120
140
1W Power LED Series
Version 3.0
Page 13 of 15
WAH WANG HOLDINGS (HONG KONG) CO., LTD.
Factory
: WAH WANG OPTOELECTRONIC (SHENZHEN) CO LTD;
PRECAUTION IN USE
Storage
1.
2.
3.
Recommended storage environment:
i. Temperature:
5oC ~ 30oC (41oF ~ 86oF)
ii. Humidity:
60% RH Max.
Recommend the use of drying cabinet storage.
Recommended storage time: 1 month
(LEDs stored over 1 month require baking treatment (Use 2. as below) before using)
Use
1.
2.
3.
4.
Please check the Humidity indicator card after opening of sealed vapor/ESD (Picture 1.) If the 40% circle color is still blue, the
product could normal use. Otherwise, 40% circle color is pink; please follow below Baking treatment before normal use.
Baking treatment : Open-static bag, the product and reel dial out from the Static bag, and then 75±5℃ for 8 hours baking treatment.
o
After de-sealed, LEDs must be used within 12 hours (under conditions ≤ 30 C, ≤ 60% RH)
Remaining product be sealed in time, recommend storage in dry cabinet storage. It requires baking treatment before re-sealed.
Handling Precautions
Compare to epoxy encapsulant that is hard and brittle, silicone is softer and flexible. Although its characteristic
significantly reduces thermal stress, it is more susceptible to damage by external mechanical force . As a result,
1. Handle the component along the side surface by using forceps or appropriate tools.
2. Do not directly touch or handle the silicone lens surface. It may damage the internal circuitry
3. Do not stack together assembled PCBs containing LEDs. Impact may scratch the silicone lens or damage
Soldering
A. Reflow Process
Reflow Soldering
Lead Solder
120~150℃
120sec. Max.
240℃ Max.
10sec. Max.
refer to
Temperaturep ofile 1
Pre-heat
Pre-heat time
Peak temperature
Sol ering time
Condition
Lead – free Solder
180~200℃
120sec. Max.
260℃ Max.
10sec. Max.
refe to
Tempera u eprofile 2
After reflow soldering rapid cooling should be avoided.
[Temperature-profile (Surface of circuit board)] Use the conditions shown to the under figure.
＜1 : Lead Solder＞
＜2 : Lead-free Solder＞
240°C Max.
10sec. Max.
2.5~5°C/sec.
Pre-heating
120~150°C
60sec. Max.
120sec. Max.
260°C Max.
10sec. Max.
1~5°C/sec.
Pre-heating
180~200°C
60sec. Max.
120sec. Max.
1~5°C/sec.
2.5~5°C/sec.
B. Manual Soldering Process
Hand Soldering
Temperature
Soldering time
350℃ Max.
3sec. Max.
(one time only)
a. For prototype builds or small series production runs it is possible to place and solder the LED by hand.
b. Dispense thermal conductive glue or grease on the substrates and follow its curing specifications. Gently press LED housing to closely
connect LED and substrate.
c. It is recommended to hand solder the leads with a solder tip temperature of 280°C for less than 3 second, at a time with a soldering iron
of less than 25W. Solder at intervals of two seconds or more.
d. Take caution and be aware that damaged products are often a result of improper hand soldering technique.
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WAH WANG HOLDINGS (HONG KONG) CO., LTD.
Factory
: WAH WANG OPTOELECTRONIC (SHENZHEN) CO LTD;
Rework
1. Customer must finish rework within 5 sec under 260℃
2. The head of iron cannot touch the resin
3. Twin-head type is preferred.
Cleaning :
The conditions of cleaning after soldering:
An alcohol-based solvent such as lsopropyl Alcohol(IPA) is recommended.
Temperature Time:<50℃*30sec,or <30℃*3min
Ultra sonic cleaning:<15W/bath; Bath volume:1liter max.
Curing:100 max,<3min
Cautions of Pick and Place:
It should be avoided to load stress on the resin during high temperature.
Avoid rubbing or scraping the resin by any object.
Electric-static may cause damage to the component. Please confirm that the equipment is grounding well. Using an ionizer fan is
recommended.
Cautions of Design and Applications:
It should be done to connect with a current-limiting serial resistor. Avoid to drive reverse voltage over the specifications on LED when
ON/OFF. Any application should refer to the specifications of absolute maximum ratings.
The dimensions of the recommended soldering pattern may mot meet every users. Please confirm and study before designing the
soldering pattern in order to obtain the best performance of soldering.
Do not contact with any component on the assembly board.
Static Electricity:
These products are so sensitive to static electricity charge so that all equipment and machinery must be properly grounded and it is
recommended to use a wristband or anti-electrostatic glove when handing the SMD LED.
Particularly if any over-current and over-voltage which exceed the Absolute Maximum Ratings of LED applied, the more energy may cause
damage or possibly result in electrical destruction of the Products.
A protection design should be installed in the LED driving circuit, which does not exceed the max. rating for surge current during on/off
switching.
A tip if soldering iron is requested to be grounded .An ionizer should be installed when risk of static generation is high.
If the countermeasures mentioned above are implemented, LED can work well.
Users are required to check those countermeasures when problems occur by static electricity charge
Other:
Damaged SMD LED will show unusual characteristics such as leak current remarkably low current. Increase, turn-on voltage becomes
lower and the SMD LED get unlighted at low current.
In automatic mounting of the SMD LEDs on printed circuit boards, any bending and pulling forces or shock against the SMD LEDs shall be
kept min. to prevent them from expanding or electrical failures and mechanical damages of the devices.
Illustration & Application:
The SMD LED taping is much smaller than leaded components, thus enable smaller size, applications, etc. higher packing density,
reduced storage space and finally smaller equipment board to be obtained. Besides, lightweight makes them ideal for miniature
The products described in this brochure are intended only for standard applications or general electronic equipment such as :
1. Telecommunication: indicator and backlight in telephone and fax.
2. Automotive: backlight in dashboard and switch.
3. LCD: Flat backlight for LCD, switch and symbol.
Notes for designing:
Care must be taken to provide the current limiting resistor in the circuit so as to drive the Wah Wang LEDs within the rated figures. Also,
caution should be taken not to overload Wah Wang LEDs with instantaneous voltage at the turning ON and OFF of the circuit.
When using the pulse drive care must be taken to keep the average current within the rated figures. Also, the circuit should be
designed so as be subjected to reverse voltage when turning off the Wah Wang LEDs.
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