Smt Led
Smt Led
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| 2pc 7440 Amber Yellow Spider Lite 24 SMD LED Front Turn Signal Light Bulb DC 12V | ![]() |
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US $24.20 | 28m |
| 2pc 7443 T20 18x 5050 3 Chip SMD SMT LED White Daytime Running light Bulb DC 12V | ![]() |
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US $18.20 | 38m |
| 2pc 1157 Bay15d 68 3528 SMD SMT LED Super White Tail Light Rear Lamp Bulb DC 12V | ![]() |
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US $18.99 | 38m |
| 2x 1157 Bay15d Super Red 68 3528 SMD SMT LED Parking Park Light Bulb DC 12V 2pc | ![]() |
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US $21.50 | 1h 9m |
| 2x 7440 T20 Amber Yellow 42 3528 SMD LED Backup Reverse Tail Light Bulb 12V 2pc | ![]() |
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US $23.10 | 1h 9m |
| 2pc 7443 T20 68x 3528 SMD SMT LED Super White Rear Turn Signal Light Bulb DC 12V | ![]() |
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US $19.00 | 1h 38m |
| 2pc 7440 Amber Yellow Spider Lite 24 SMD LED Rear Turn Signal Light Bulb DC 12V | ![]() |
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US $24.20 | 1h 49m |
| 2pc H1 25x 3528 SMD SMT LED Super White HID Look Fog Driving Light Bulb DC 12V | ![]() |
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US $16.50 | 2h 14m |
| 2pc 9006 HB4 Xenon White HID Look 18 5050 SMD SMT LED Fog Driving Light Bulb 12V | ![]() |
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US $25.30 | 2h 14m |
| 2pc 7443 T20 18x 5050 3 Chip SMD SMT LED White Tail Light Rear Lamp Bulb DC 12V | ![]() |
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US $18.20 | 2h 14m |
| 2pc 7440 Spider Lite 24 SMD LED Amber Yellow Rear Turn Signal Light Bulb DC 12V | ![]() |
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US $27.99 | 2h 14m |
| T10 Bulbs SMT SMD 5 LED Wedge White L 1037 | ![]() |
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US $4.95 | 2h 21m |
| T10 Bulbs SMT SMD 9 LED Wedge White L 1038 | ![]() |
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US $4.95 | 2h 21m |
| 2 Xenon White 4 SMD 1210 2825 175 LED Interior Dome Lights Bulbs | ![]() |
3 Bids | US $4.50 | 2h 24m |
| 2 Ultra Blue 18 SMD 1157 7528 LED Brake Lights Bulbs | ![]() |
0 Bid | US $15.99 | 2h 24m |
| 2 Ultra Blue 18 SMD 1157 LED Turn Signal Lights Bulbs | ![]() |
0 Bid | US $15.99 | 2h 24m |
| Xenon White 5 SMD 1210 2825 175 LED Car Interior Dome Lights Bulbs | ![]() |
0 Bid | US $4.99 | 2h 25m |
| 2pc 7440 T20 18x 5050 3 Chip SMD LED White Rear Turn Signal Light Bulb DC 12V | ![]() |
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US $18.20 | 3h 29m |
| 2pc 9006 HB4 68x SMD SMT LED Super Bright White Fog Driving Light Bulb DC 12V | ![]() |
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US $31.00 | 3h 53m |
| 2x H1 Socket 6000K Xenon White 68 3528 SMD SMT LED Fog Driving Light Bulb DC 12V | ![]() |
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US $24.20 | 4h 3m |
| T10 WEDGE BULBS 2 PCS SMD SMT 9 LED HID WHITE L 1143 | ![]() |
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US $1.55 | 4h 6m |
| 2pc 7443 T20 18x 5050 3 Chip SMD SMT LED White Stop Brake Tail Light Bulb DC 12V | ![]() |
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US $15.00 | 4h 18m |
| GU10 48 LED SMT 192 Lumen White Light BulbAC 110V | ![]() |
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US $10.66 | 4h 33m |
| Bulbs White 194 168 T10 158 SMD SMT 5 LED Light NEW 10 | ![]() |
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US $5.99 | 4h 53m |
| 2x 7440 T20 Xenon White 18 5050 SMD LED Backup Reverse Tail Light Bulb DC 12V | ![]() |
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US $14.99 | 5h 9m |
| PAR30 30 SMT LED Cool White Flood 6 Watts 120 230VAC for Track or Recessed Light | ![]() |
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US $19.95 | 5h 13m |
| 2pc 7443 T20 68x 3528 SMD SMT LED Super White Tail Light Rear Lamp Bulb DC 12V | ![]() |
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US $19.00 | 5h 19m |
| 2pc H11 68x 3528 SMD SMT LED Super Bright White Fog Driving Light Bulb DC 12V | ![]() |
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US $31.99 | 5h 43m |
| 50p 1206 SMD SMT BRIGHT BLUE LED LAMP LIGHT 1000mcd | ![]() |
2 Bids | US $.06 | 5h 47m |
| 2pc H1 13x 5050 SMD SMT LED Super White HID Look Fog Driving Light Bulb DC 12V | ![]() |
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US $14.30 | 6h 58m |
| 2pc 3157 Amber Yellow 68 3528 SMD SMT LED Brake Stop Tail Light Bulb DC 12V Set | ![]() |
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US $23.10 | 6h 58m |
| 2x 3157 Super Red 68 3528 SMD SMT LED Parking Park Light Bulb DC 12V 2pc Set New | ![]() |
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US $24.20 | 7h 9m |
| 2pc 3157 Amber Yellow 68 3528 SMD SMT LED Back up Reverse Tail Light Bulb DC 12V | ![]() |
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US $23.10 | 7h 13m |
| PAR30 30 SMT LED Warm White Flood 6 Watts 120 230VAC for Track or Recessed Light | ![]() |
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US $19.95 | 7h 38m |
| 100PCS 3528 PLCC 2 SMD SMT LED 1300MCD white | ![]() |
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US $6.64 | 8h 10m |
| 2pc 7443 T20 Dual Contact 68 3528 SMD LED Red Rear Side Marker Light Bulb DC 12V | ![]() |
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US $24.20 | 9h 9m |
| 2x 7440 T20 Xenon White 18 5050 SMD SMT LED Rear Turn Signal Light Bulb DC 12V | ![]() |
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US $14.99 | 9h 9m |
| 2x 7443 T20 Super Red 68 3528 SMD SMT LED Rear Side Marker Light Bulb DC 12V 2pc | ![]() |
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US $20.99 | 9h 24m |
| 100 Pcs SMD SMT LED 0805 White Blue Red Green Yellow 20 pcs each Assortment | ![]() |
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US $11.50 | 9h 42m |
| 100 Pcs SMD SMT LED 0603 White Blue Red Green Yellow 20 pcs each Assortment | ![]() |
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US $11.50 | 9h 44m |
| 2 Bulbs Pair White 194 168 T10 SMD SMT 5 LED Light NEW | ![]() |
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US $1.00 | 9h 49m |
| 50p 1206 SMD SMT WARM WHITE LED LAMP LIGHT 2300mcd | ![]() |
1 Bid | US $.01 | 10h 44m |
| 5pcs Red 1210 PLCC 2 Super Bright Car Vehicle DASH SMD SMT LED Lamp Light Bulb | ![]() |
1 Bid | US $.99 | 11h 47m |
| 10x Bulbs White 194 168 T10 SMD SMT 8 LED Car Light 12V | ![]() |
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US $13.59 | 12h 14m |
| 5PCS Green 1210 PLCC 2 Super Bright Car Boat DASH SMD SMT LED Lamp Light Bulb | ![]() |
0 Bid | US $.99 | 12h 31m |
| 5pcs Yellow 1210 PLCC 2 Super Bright Car Boat DASH SMD SMT LED Lamp Light Bulb | ![]() |
2 Bids | US $1.04 | 12h 45m |
| 2pcs T10 168 194 25 SMD SMT LED HID White Wedge Bulbs | ![]() |
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US $5.79 | 12h 56m |
| 2pcs T10 W5W 168 194 25 SMD SMT LED Blue Wedge Bulbs | ![]() |
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US $5.79 | 12h 57m |
| 2pcs T10 168 194 17 SMD SMT LED HID White Wedge Bulbs | ![]() |
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US $23.92 | 13h 3m |
| 5pc White 1210 PLCC 2 Super Bright Car Vehicle DASH SMD SMT LED Lamp Light Bulb | ![]() |
4 Bids | US $2.25 | 13h 4m |
| 1000pcs White 1206 Super Bright SMD SMT LED Lamp Light | ![]() |
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US $58.00 | 13h 24m |
| 5pcs Blue 1210 PLCC 2 Super Bright Car Boat DASH SMD SMT PCB LED Lamp Light Bulb | ![]() |
2 Bids | US $1.04 | 13h 26m |
| 1000pcs Green 1206 Super Bright SMD SMT LED Lamp Light | ![]() |
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US $39.95 | 13h 27m |
| 1000pcs Green 0805 Super Bright SMD SMT LED Lamp Light | ![]() |
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US $39.90 | 13h 28m |
| 100X Blue 0805 Super Bright DASH SMD SMT LED Lamp Light | ![]() |
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US $6.90 | 13h 29m |
| 1000pcs Green 0603 Extra Bright SMD SMT LED Lamp Light | ![]() |
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US $39.80 | 13h 29m |
| 100X Blue 0603 Super Bright DASH SMD SMT LED Lamp Light | ![]() |
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US $6.85 | 13h 30m |
| 1000pcs Blue 1206 Super Bright SMD SMT LED Lamp Light | ![]() |
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US $58.00 | 13h 32m |
| 10pcs Blue 1210 PLCC 2 Super Bright Car Boat DASH SMD SMT LED Lamp Light Bulb | ![]() |
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US $1.98 | 13h 35m |
| 10pcs Blue 1206 Super Bright SMD SMT LED Lamp Light | ![]() |
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US $1.95 | 13h 36m |
| 10x Green 0805 Extra Bright SMD SMT DASH LED Lamp Light | ![]() |
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US $1.95 | 13h 46m |
| 10x Green 0603 Extra Bright SMD SMT DASH LED Lamp Light | ![]() |
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US $1.96 | 13h 47m |
| 100White 0805 Super Bright Dash SMD SMT LED Lamp Light | ![]() |
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US $6.90 | 14h 9m |
| 100White 0603 Super Bright Dash SMD SMT LED Lamp Light | ![]() |
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US $6.85 | 14h 10m |
| 20 pcs POWER TOP SMD SMT PLCC 2 1210 3528 white LED | ![]() |
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US $3.74 | 14h 35m |
| 50 pcs POWER TOP SMD SMT PLCC 2 1210 3528 white LED | ![]() |
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US $5.24 | 14h 40m |
| 54x33cm Car Vechile H7 18 LED SMD SMT Xenon Fog Headlight Headlamp Replacement | ![]() |
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US $8.59 | 14h 43m |
| 100 pcs POWER TOP SMD SMT PLCC 2 1210 3528 white LED | ![]() |
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US $7.49 | 14h 44m |
| 200 pcs POWER TOP SMD SMT PLCC 2 1210 3528 white LED | ![]() |
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US $11.99 | 14h 48m |
| 1000 pcs POWER TOP SMD SMT PLCC 2 1210 3528 white LED | ![]() |
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US $54.00 | 14h 49m |
| 10pc White 1210 PLCC 2 Super Bright Car Vehicle DASH SMD SMT LED Lamp Light Bulb | ![]() |
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US $1.98 | 14h 51m |
| 10PC Green 1210 PLCC 2 Super Bright Car Vehicle DASH SMD SMT LED Lamp Light Bulb | ![]() |
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US $1.98 | 15h 11m |
| FRI LED 12 Super White 12V SMD SMT DOME DOOR BOX CAR LIGHT 7D | ![]() |
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US $4.61 | 15h 16m |
| 10pc Blue 0805 Super Bright DASH SMD SMT LED Lamp Light | ![]() |
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US $2.50 | 15h 22m |
| 10pc Blue 0603 Super Bright DASH SMD SMT LED Lamp Light | ![]() |
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US $2.45 | 15h 23m |
| 20 pcs SMD SMT PLCC 2 1210 3528 Warm white light LED | ![]() |
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US $3.74 | 15h 24m |
| 1Car 9 SMD SMT Led Xenon Fog RED H3 Bulb Light 12VH3R | ![]() |
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US $10.95 | 15h 31m |
| 100pcs Yellow 0805 Super Bright SMD SMT LED Lamp Light | ![]() |
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US $4.90 | 15h 32m |
| FRI LED 24 Super White 12V SMD SMT DOME DOOR BOX CAR LIGHT | ![]() |
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US $5.64 | 15h 32m |
| 100pcs Yellow 0603 Super Bright SMD SMT LED Lamp Light | ![]() |
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US $4.88 | 15h 33m |
| 100pcs Green 0805 Extra Bright SMD SMT LED Lamp Light | ![]() |
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US $4.90 | 15h 56m |
| 10p White 1206 Super Bright Dash SMD SMT LED Lamp Light | ![]() |
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US $1.95 | 15h 58m |
| 10p White 0805 Super Bright Dash SMD SMT LED Lamp Light | ![]() |
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US $2.50 | 15h 59m |
| 10p Green 1206 Super Bright Dash SMD SMT LED Lamp Light | ![]() |
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US $1.95 | 16h 16m |
| 100 Green 0603 Extra Bright SMD SMT DASH LED Lamp Light | ![]() |
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US $4.88 | 16h 28m |
| 100pc Red 0805 Extra Bright DASH SMD SMT LED Lamp Light | ![]() |
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US $4.90 | 16h 34m |
| 100pc Red 0603 Super Bright DASH SMD SMT LED Lamp Light | ![]() |
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US $4.88 | 16h 35m |
| 2x 1156 Bau15S Ba15s 20 SMD SMT 5050 LED AUTO SIGNAL TURN LIGHT Bulbs AMBER | ![]() |
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US $18.99 | 16h 39m |
| 2x 7443 T20 W21W 20 SMT 5050 LED Auto Backup Side Stop Brake Light Bulbs RED | ![]() |
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US $18.99 | 16h 39m |
| 10x White 0603 Super Bright Dash SMD SMT LED Lamp Light | ![]() |
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US $2.45 | 16h 48m |
| 20 x POWER TOP SMD SMT PLCC 2 1210 3528 Blue LED light | ![]() |
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US $3.74 | 17h 2m |
| 10pcs Yellow 1210 PLCC 2 Super Bright Car Boat DASH SMD SMT LED Lamp Light Bulb | ![]() |
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US $1.98 | 17h 8m |
| 10pcs Yellow 1206 Super Bright SMD SMT LED Lamp Light | ![]() |
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US $1.95 | 17h 9m |
| 50 x POWER TOP SMD SMT PLCC 2 1210 3528 Blue LED light | ![]() |
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US $5.99 | 17h 15m |
| 100 x POWER TOP SMD SMT PLCC 2 1210 3528 Blue LED light | ![]() |
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US $7.49 | 17h 16m |
| 200 x POWER TOP SMD SMT PLCC 2 1210 3528 Blue LED light | ![]() |
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US $11.99 | 17h 16m |
| 500 x POWER TOP SMD SMT PLCC 2 1210 3528 Blue LED light | ![]() |
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US $17.24 | 17h 16m |
How does Juction temperature work?
Tj = Ta + Rj-a x P
Help me on explaining this.
Let say the system is an SMT LED, how to calculate and why?
Rj(a) - thermal resistance at ambient temp
Ta = ambient temperature
Power = total power requirement of device
You will find values of Rj in the datasheet of device - provide Ta at around 25 degrees for initial start up of circuit. Provide power requirements of your device - the one you will be providing.
Junction Temperature is used to study the performance characterstics of an I.C/component at different level of temperatures. Manufacturers provide you Ambient Temperature performance Ch's of internal thermal resistance, current, voltage, you decide the power requirements - then you calculate the junction temperature. It may be noted performance decreases with increase in J. LED may not be very suitable to study these effects in detail - better take mosfet or IGBT - read the datasheets - Consider IRF Z44N mosfet - it can provide you 49A @55 volts @ 25 degrees cent - but with increase in temperature say 175 degrees cent, - the thermal resistance (drain to source) increase - you will see more power losses and the mosfet will heat more.
Also, the formula you mentioned is used to design the heat sink design.
Pls check http://www.irf.com/technical-info/papers.html - they have provided detailed theory behind Tj, thermal resistance in their TN's
Also check TN's, DN's from fairchild, Texas Instruments, Linfinity
T10 BMW 2 White SMD LED bulb i26



