6 Thermal Measures

AN2242

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6

Thermal Measures

In order to check the design reliability, a thermal mapping by means of an IR Camera was

done. Here below the thermal measures of the component board side at nominal input voltage

are shown. Some pointers visible on the pictures have been placed across key components or

components showing high temperature. The correlation between measurement points and

components is indicated on the right of both figures.

Figure 27. 115Vac-Max Load

Figure 28. 230Vac-Max Load

The thermistor, bridge and output diodes temperature rise are compatible with the reliable

operation of the components. Resistor R7 may need a bigger package to decrease its thermal

resistance. All other components of the board are working within the temperature limits

assuring a reliable long term operation of the power supply.

A 83.70°C E= 0.95

R1 (NTC)

B 58.29°C E= 0.95

D1 (BRIDGE)

C 116.60°C E= 0.95

R7 (CLAMP)

D 75.67°C E= 0.95

T1 (WINDING)

E 73.64°C E= 0.95

T1 (FERRITE)

F 98.34°C E= 0.95

D2

G 73.85°C E= 0.95

D10

H 69.91°C E= 0.95

D12

A 94.63°C E= 0.95

R7 (CLAMP)

B 69.85°C E= 0.95

T1 (WINDING)

C 67.62°C E= 0.95

T1 (FERRITE)

D 97.50°C E= 0.95

D2

E 76.15°C E= 0.95

D10

F 69.29°C E= 0.95

D12