Flameproof Power

Metal Film Resistors

MFP Series

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Issue D · 03.06

Welwyn Components

144

Application Notes

1. If the resistors are to dissipate full rated power, it is

recommended that the terminations should not be

soldered closer than 4mm from the body.

2. Due to operating temperature limitations imposed by some

pcb materials, derating may be necessary. An estimate of

the temperature rise to be expected can be calculated

using the thermal impedance figures given under Electrical

Data.

3. MFP resistors an also be supplied pre-formed.

b

6

6

5

≤ 1.4 mm

Figure 1

Packaging

MFP resistors are normally supplied tape packed ready for

loading onto automatic sequencing and insertion machines.

The standard taping method and critical dimensions are

shown in Figure 1.

Component wires will not protrude beyond the outside edge

of the tapes.

Alternative packaging available by request.

Lead Formed resistors can also be supplied. Standard options

of Lancet, Radial and Goalpost forming are shown in lead

Form Information section.

Maximum

Load at rated power : 1000 hours at 70°C

∆R %

5

Shelf life : 12 months at room temperature

∆R %

2

Derating from rated power at 70°C

∆R %

zero at 155°C

Climatic

∆R %

3

Climatic category

50/155/56

Temperature rapid change

∆R %

0.5

Resistance to solder heat

∆R %

0.5

Voltage proof

volts

500 min

Performance Data

Type

MFP1

MFP2

Ammo pack

5000

2000

Standard Quantities Per Package

Type

MFP1

MFP2

b (mm)

52

68