Smt Led
Smt Led
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| 2pc 7440 T20 42x 3528 SMD LED Amber Yellow Backup Reverse Tail Light Bulb DC 12V | ![]() |
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US $19.99 | 16m |
| 2pc H1 13x 5050 SMD SMT LED Super White HID Look Fog Driving Light Bulb DC 12V | ![]() |
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US $17.60 | 36m |
| 2pc 7443 T20 68x 3528 SMD SMT LED Super White Rear Side Marker Light Bulb DC 12V | ![]() |
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US $19.00 | 56m |
| 2 Ultra Blue 18 SMD H8 H11 LED Driving Fog Lights Bulbs | ![]() |
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US $29.74 | 1h 3m |
| 30 SMT SMD 37W LED 19 Rigid Cool White Light Strip 12VDC or 12VAC U Can Cut It | ![]() |
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US $14.95 | 1h 4m |
| 2pc 7443 T20 Dual Filament 68x 3528 SMD LED White Parking Park Light Bulb DC 12V | ![]() |
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US $19.00 | 1h 9m |
| 2pc H11 68x 3528 SMD SMT LED Super Bright White Fog Driving Light Bulb DC 12V | ![]() |
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US $35.20 | 1h 9m |
| 2pc 3157 Socket 18x 5050 3 Chip SMD SMT LED White Parking Park Light Bulb DC 12V | ![]() |
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US $14.50 | 1h 16m |
| 2 pc White 68 SMD 9006 HB4 LED Driving Fog Lights Bulbs | ![]() |
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US $33.99 | 1h 37m |
| 2pc 7440 7441 7444 992 T20 42x SMD LED Red Rear Turn Signal Light Bulb DC 12V | ![]() |
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US $17.60 | 1h 56m |
| 2 Car Xenon White 24 SMD SMT LED T20 Tail Light BULB | ![]() |
0 Bid | US $.99 | 1h 58m |
| 2pc 3157 T20 18x 5050 3 Chip SMD SMT LED White Brake Stop Tail Light Bulb DC 12V | ![]() |
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US $14.50 | 2h 16m |
| White 18 SMD H16 5202 LED Driving Fog Light Bulbs Chevy | ![]() |
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US $29.74 | 3h 15m |
| 2pc 7443 T20 Dual Contact 68x 3528 SMD LED Red Tail Light Rear Lamp Bulb DC 12V | ![]() |
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US $24.20 | 3h 36m |
| 1pc Xenon White 5 SMD T10 168 175 194 2825 LED License Dome Cargo Light Bulb | ![]() |
1 Bid | US $4.99 | 3h 41m |
| 10 pcs T10 194 168 W5W 10 SMD LED SMT Car Wedge Tail Light Lamp Bulb 12V Blue | ![]() |
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US $8.98 | 3h 56m |
| 10 pcs T10 194 168 W5W 10 SMD LED SMT Car Wedge Tail Light Lamp Bulb 12V Red | ![]() |
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US $8.09 | 3h 56m |
| 2pc 7443 T20 18x 5050 3 Chip SMD LED White Front Side Marker Light Bulb DC 12V | ![]() |
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US $18.20 | 4h 1m |
| 2x CAR 18 LED SMD SMT WHITE BULB 9005 HB3 FOG LIGHT 12V | ![]() |
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US $14.29 | 4h 14m |
| T10 LICENSE PLATE 8 LED WEDGE BULBS SMD SMT HID WHITE | ![]() |
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US $4.39 | 4h 15m |
| 2x 7440 T20 Xenon White 18 5050 SMD SMT LED Rear Turn Signal Light Bulb DC 12V | ![]() |
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US $17.99 | 4h 15m |
| 2x H1 6000K Xenon White 68 3528 SMD SMT LED Fog Driving Light Bulb DC 12V 2pc | ![]() |
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US $21.00 | 4h 15m |
| 2x 7440 T20 Amber Yellow 42 3528 SMD LED Backup Reverse Tail Light Bulb 12V 2pc | ![]() |
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US $23.10 | 4h 15m |
| 2x 7443 T20 Super Red 68 3528 SMD SMT LED Tail Light Rear Lamp Bulb DC 12V 2pc | ![]() |
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US $20.99 | 4h 15m |
| 2x 7443 T20 Dual Contact Xenon White 68 SMD LED Tail Light Rear Lamp Bulb DC 12V | ![]() |
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US $22.60 | 4h 15m |
| 2x 9006 HB4 Xenon White 18 5050 3 Chip SMD SMT LED Fog Driving Light Bulb DC 12V | ![]() |
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US $21.99 | 4h 15m |
| 2x 7440 T20 Super Red 42 3528 SMD SMT LED Rear Turn Signal Light Bulb DC 12V 2pc | ![]() |
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US $21.00 | 4h 15m |
| 2x 7440 T20 Xenon White 18 5050 SMD LED Backup Reverse Tail Light Bulb DC 12V | ![]() |
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US $17.99 | 4h 15m |
| 2pc 3157 18x 5050 3 Chip SMD SMT LED White Tail Light Rear Lamp Bulb DC 12V Pair | ![]() |
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US $14.50 | 4h 17m |
| 5W White 68 SMD P13W LED Daytime Fog Lights Bulbs Chevy | ![]() |
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US $42.49 | 4h 25m |
| T10 WEDGE BULBS 2 PCS SMD SMT 12 LED HID WHITE L 1142 | ![]() |
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US $3.99 | 4h 34m |
| 2x Car Truck Vehicle 9006 HB4 3528 102 SMD SMT LED Head Light Fog DRL Bulb Lamp | ![]() |
0 Bid | US $11.99 | 4h 49m |
| 2pc 7443 T20 68x 3528 SMD SMT LED Super White Tail Light Rear Lamp Bulb DC 12V | ![]() |
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US $22.00 | 5h 16m |
| NEW 50 PCS PLCC 6 5050 Manual Control SMD SMT RGB LED | ![]() |
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US $26.00 | 5h 24m |
| 1156 BULB 2PCS SMT SMD 68 LED HID WHITE FOGLIGHT L 1111 | ![]() |
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US $12.90 | 5h 28m |
| Brand Hot 12V Car 9006 HB4 3528 102 SMD SMT LED White Light Bulb Head Lamp Fog Q | ![]() |
0 Bid | US $5.35 | 5h 50m |
| 12V Car 9006 HB4 3528 102 SMD SMT LED White Light Bulb Head Lamp Fog V1 | ![]() |
0 Bid | US $4.94 | 6h 25m |
| 2pc 7443 T20 68x 3528 SMD SMT LED Super White Stop Brake Tail Light Bulb DC 12V | ![]() |
1 Bid | US $17.20 | 7h 1m |
| 1 PCS H7 BULB SMT SMD 68 LED HID WHITE FOG CAR LIGHT | ![]() |
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US $4.89 | 8h 16m |
| New 0805 red smd smt led 200pcs | ![]() |
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US $12.99 | 9h 16m |
| New 0805 red smd smt led 500pcs | ![]() |
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US $28.99 | 9h 17m |
| New 0805 red smd smt led 1000pcs | ![]() |
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US $49.99 | 9h 17m |
| New 0805 red smd smt led 3000pcs | ![]() |
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US $138.99 | 9h 18m |
| 5 x 1206 Emerald Green Super Bright LED SMD SMT Bulb Lamp Light High Brightness | ![]() |
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US $1.48 | 9h 42m |
| 5 x 1206 Amber Super Bright LED SMD SMT Bulb Lamp Light High Brightness RoHs | ![]() |
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US $1.48 | 9h 42m |
| 5 x 1206 White Super Bright LED SMD SMT Bulb Lamp Light High Brightness RoHs | ![]() |
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US $1.48 | 9h 42m |
| 5 x 1206 RED Super Bright LED Chip SMD SMT Bulb Lamp Light High Brightness RoHs | ![]() |
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US $1.48 | 9h 42m |
| 5 x 1206 Yellow Green Super Bright LED SMD SMT Bulb Lamp Light High Brightness | ![]() |
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US $1.48 | 9h 42m |
| 5 x 1206 Blue Super Bright LED SMD SMT Bulb Lamp Light High Brightness RoHs | ![]() |
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US $1.48 | 9h 42m |
| 10 x 1206 Yellow Green Super Bright LED SMD SMT Bulb Lamp Light High Brightness | ![]() |
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US $1.83 | 9h 43m |
| 10 x 1206 Amber Super Bright LED SMD SMT Bulb Lamp Light High Brightness RoHs | ![]() |
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US $1.83 | 9h 43m |
| 10 x 1206 Emerald Green Super Bright LED SMD SMT Bulb Lamp Light High Brightness | ![]() |
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US $1.83 | 9h 43m |
| 10 x 1206 White Super Bright LED SMD SMT Bulb Lamp Light High Brightness RoHs | ![]() |
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US $1.83 | 9h 43m |
| 10 x 1206 Blue Super Bright LED SMD SMT Bulb Lamp Light High Brightness RoHs | ![]() |
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US $1.83 | 9h 43m |
| 10 x 1206 RED Super Bright LED Chip SMD SMT Bulb Lamp Light High Brightness RoHs | ![]() |
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US $1.83 | 9h 43m |
| 20 x 1206 Amber Super Bright LED SMD SMT Bulb Lamp Light High Brightness RoHs | ![]() |
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US $1.98 | 9h 43m |
| 20 x 1206 RED Super Bright LED Chip SMD SMT Bulb Lamp Light High Brightness RoHs | ![]() |
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US $1.98 | 9h 43m |
| 20 x 1206 Yellow Green Super Bright LED SMD SMT Bulb Lamp Light High Brightness | ![]() |
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US $1.98 | 9h 44m |
| 20 x 1206 White Super Bright LED SMD SMT Bulb Lamp Light High Brightness RoHs | ![]() |
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US $2.53 | 9h 44m |
| 20 x 1206 Blue Super Bright LED SMD SMT Bulb Lamp Light High Brightness RoHs | ![]() |
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US $2.53 | 9h 44m |
| 20 x 1206 Emerald Green Super Bright LED SMD SMT Bulb Lamp Light High Brightness | ![]() |
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US $2.53 | 9h 44m |
| 50 x 1206 RED Super Bright LED Chip SMD SMT Bulb Lamp Light High Brightness RoHs | ![]() |
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US $2.94 | 9h 44m |
| 50 x 1206 Yellow Green Super Bright LED SMD SMT Bulb Lamp Light High Brightness | ![]() |
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US $2.94 | 9h 44m |
| 50 x 1206 Amber Super Bright LED SMD SMT Bulb Lamp Light High Brightness RoHs | ![]() |
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US $2.94 | 9h 44m |
| 50 x 1206 Blue Super Bright LED SMD SMT Bulb Lamp Light High Brightness RoHs | ![]() |
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US $3.98 | 9h 44m |
| 50 x 1206 White Super Bright LED SMD SMT Bulb Lamp Light High Brightness RoHs | ![]() |
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US $4.48 | 9h 44m |
| 50 x 1206 Emerald Green Super Bright LED SMD SMT Bulb Lamp Light High Brightness | ![]() |
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US $4.48 | 9h 45m |
| 100 1206 RED Super Bright LED Chip SMD SMT Bulb Lamp Light High Brightness RoHs | ![]() |
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US $5.83 | 9h 45m |
| 100 x 1206 Yellow Green Super Bright LED SMD SMT Bulb Lamp Light High Brightness | ![]() |
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US $5.83 | 9h 45m |
| 100 x 1206 Amber Super Bright LED SMD SMT Bulb Lamp Light High Brightness RoHs | ![]() |
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US $5.83 | 9h 45m |
| 100 1206 Emerald Green Super Bright LED SMD SMT Bulb Lamp Light High Brightness | ![]() |
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US $6.63 | 9h 45m |
| 100 1206 White Super Bright LED SMD SMT Bulb Lamp Light High Brightness RoHs | ![]() |
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US $6.63 | 9h 45m |
| 100 x 1206 Blue Super Bright LED SMD SMT Bulb Lamp Light High Brightness RoHs | ![]() |
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US $6.63 | 9h 45m |
| 200 1206 RED Super Bright LED Chip SMD SMT Bulb Lamp Light High Brightness RoHs | ![]() |
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US $10.53 | 9h 45m |
| 200 x 1206 Amber Super Bright LED SMD SMT Bulb Lamp Light High Brightness RoHs | ![]() |
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US $10.53 | 9h 46m |
| 200 x 1206 Yellow Green Super Bright LED SMD SMT Bulb Lamp Light High Brightness | ![]() |
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US $10.53 | 9h 46m |
| 200 1206 White Super Bright LED SMD SMT Bulb Lamp Light High Brightness RoHs | ![]() |
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US $12.63 | 9h 46m |
| 200 1206 Emerald Green Super Bright LED SMD SMT Bulb Lamp Light High Brightness | ![]() |
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US $12.63 | 9h 46m |
| 200 x 1206 Blue Super Bright LED SMD SMT Bulb Lamp Light High Brightness RoHs | ![]() |
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US $12.63 | 9h 46m |
| 300 x 1206 Amber Super Bright LED SMD SMT Bulb Lamp Light High Brightness RoHs | ![]() |
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US $15.68 | 9h 46m |
| 300 1206 RED Super Bright LED Chip SMD SMT Bulb Lamp Light High Brightness RoHs | ![]() |
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US $15.68 | 9h 46m |
| 300 x 1206 Yellow Green Super Bright LED SMD SMT Bulb Lamp Light High Brightness | ![]() |
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US $15.68 | 9h 46m |
| 300 1206 White Super Bright LED SMD SMT Bulb Lamp Light High Brightness RoHs | ![]() |
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US $18.38 | 9h 46m |
| 300 x 1206 Blue Super Bright LED SMD SMT Bulb Lamp Light High Brightness RoHs | ![]() |
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US $18.38 | 9h 47m |
| 300 1206 Emerald Green Super Bright LED SMD SMT Bulb Lamp Light High Brightness | ![]() |
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US $18.38 | 9h 47m |
| 500 x 1206 Yellow Green Super Bright LED SMD SMT Bulb Lamp Light High Brightness | ![]() |
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US $25.88 | 9h 47m |
| 500 x 1206 Amber Super Bright LED SMD SMT Bulb Lamp Light High Brightness RoHs | ![]() |
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US $25.88 | 9h 47m |
| 500 1206 RED Super Bright LED Chip SMD SMT Bulb Lamp Light High Brightness RoHs | ![]() |
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US $25.88 | 9h 47m |
| 500 x 1206 Blue Super Bright LED SMD SMT Bulb Lamp Light High Brightness RoHs | ![]() |
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US $27.88 | 9h 47m |
| 500 1206 Emerald Green Super Bright LED SMD SMT Bulb Lamp Light High Brightness | ![]() |
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US $27.88 | 9h 47m |
| 500 1206 White Super Bright LED SMD SMT Bulb Lamp Light High Brightness RoHs | ![]() |
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US $27.88 | 9h 47m |
| 1000 x 1206 Amber Super Bright LED SMD SMT Bulb Lamp Light High Brightness RoHs | ![]() |
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US $44.38 | 9h 47m |
| 1000 1206 Yellow Green Super Bright LED SMD SMT Bulb Lamp Light High Brightness | ![]() |
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US $44.38 | 9h 48m |
| 1000 1206 RED Super Bright LED Chip SMD SMT Bulb Lamp Light High Brightness RoHs | ![]() |
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US $44.38 | 9h 48m |
| 1000 1206 Emerald Green Super Bright LED SMD SMT Bulb Lamp Light High Brightness | ![]() |
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US $54.88 | 9h 48m |
| 1000 1206 White Super Bright LED SMD SMT Bulb Lamp Light High Brightness RoHs | ![]() |
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US $54.88 | 9h 48m |
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



