Calculation method about electronic selection

Dissipate heat ::
RTF = (TJ -TA)/PC -RTJ -RTC
RFF is the main basis for selection. Essence Hehehe is a semiconductor device, PC is parameter, RTC is a parameter, and the parameter of the RTC parameter parameter
(1) Calculation Calculation total thermal resistance RT: RT = (TJMAX-TA)/PC
2) Calculate the heat resistance heat resistance or ΔTFA: RTF = RT -RTJ -RTCΔTFA = RTF × PC
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For profile heatware, when Dual Thermostat the heat resistance or curve cannot be used
According to the above, the scattered temperature lift ΔTFA, and then the comprehensive coefficient of the heat sink α ::
α = 7.2 Single ψ2ψ3 {√√ [(TF-TA)/20]}
Mode::
对1–L/B effect on α
对2–H/B effect on α
写3-α α αα when describing width size and size;
√√ [(TF-TA)/20]-..-Describes the pair of alphaα that describes the highest surrounding surrounding;
The above parameters can be obtained.Switchgear cabinet and enclosure heaters
Calculate the surface power power power power power power power
Q0 = α × ΔTFA × 2H+B) × L
Based on single -sided or noodle rib rib piers N, PC ‘
Single -side: PC ‘= NQ0
Double: PC ‘= 2NQ0
PC ‘> PC can. Essence Essence
parameter::
RT – -, ℃, ℃/w;
RTJ–..-intraceapture internal heat resistance, ℃/w;
RTC- ..-interface thermal resistance between semiconductor and heat sink
RTF-, radiator, ℃/w;
tj -—— ℃, ℃, ℃;
TC-, semiconductor, ℃, ℃;
TF-─, radiator, ℃, ℃;
TA-─, ℃, ℃, ℃
PC- ..-Semiconductor use power, w;
ΔTFA – -, radiator, ℃, ℃