Document Number: 28108

www.vishay.com

Revision: 04-Aug-09

89

MKT 370

DC Film Capacitors

MKT Radial Potted Type

Vishay BCcomponents

HEAT CONDUCTIVITY (G) AS A FUNCTION OF (ORIGINAL) PITCH AND CAPACITOR BODY THICKNESS IN mW/°C

POWER DISSIPATION AND MAXIMUM COMPONENT TEMPERATURE RISE

The power dissipation must be limited in order not to exceed the maximum allowed component temperature rise as a function of

the free ambient temperature.

The power dissipation can be calculated according type detail specification “HQN-384-01/101: Technical Information Film

Capacitors”.

The component temperature rise (

ΔT) can be measured (see section “Measuring the component temperature” for more details)

or calculated by

ΔT = P/G:

• ΔT = Component temperature rise (°C)

• P = Power dissipation of the component (mW)

• G = Heat conductivity of the component (mW/°C)

MEASURING THE COMPONENT TEMPERATURE

A thermocouple must be attached to the capacitor body as in:

The temperature rise is given by

ΔT = T

To avoid radiation or convection, the capacitor should be tested in a wind-free box.

Maximum allowed component temperature rise (

ΔT)

Maximum allowed component temperature rise (

ΔT)

(mm)

HEAT CONDUCTIVITY (mW/°C)

PITCH 5 mm

2.5

2.5

3.5

3.0

4.5

4.0

6.0

5.5

- 60

- 20

20

60

100

T

16

12

8

4

0

- 60

- 20

20

60

100

T

16

12

8

4

0

Thermocouple