Power Metal
Film Resistors
MF-S Series
www.bitechnologies.com www.irctt.com www.welwyn-tt.com
General Note
TT electronics reserves the right to make changes in product specification without notice or liability.
All information is subject to TT electronics’ own data and is considered accurate at time of going to print.
© TT electronics plc
01.13
· Small size for power rating
· Range of 4 sizes: 0.5 watt to 3 watt at 70°C
· Flameproof protection
Power Metal
Film Resistors
MF-S Series
Small size for power rating
Range of 4 sizes: 0.5 watt to 3 watt at 70˚C
Flameproof protection
MF1/2S MF1S MF2S MF3S
Standard values
Power rating at 70° C watts 0.5 1.0 2.0 3.0
0R1 – 1M
500
140 110 80 60
-55 to 155
700
350
< 10Ω :350 10Ω :150
E24 preferred
General Note
Welwyn Components reserves the right to make changes in product specification without notice or liability.
All information is subject to Welwyn’s own data and is considered accurate at time of going to print.
© Welwyn Components Limited · Bedlington, Northumberland NE22 7AA, UK
Telephone: +44 (0) 1670 822181 · Facsimile: +44 (0) 1670 829465 · Email: info@welwyn-tt.com · Website: www.welwyn-tt.com
Electrical Data
Issue C · 01.06
A subsidiary of
TT electronics plc
Welwyn Components
147
Dimensions (mm) & Weight (g)
PCB Min.
mounting
bend
Type L Mx D Max f min d nom centres radius Wt.nom
MF1/2S 21.0 0.6 1.02 0.6 0.3
MF1S 19.6 0.8 12.7 1.2 0.5
MF2S 17.8 0.8 18.4 1.2 0.9
MF3S 23.8 0.8 20.3 1.2 1.1
Physical Data
L
Df
d
10.2
03.08
Resistance range ohms
Limiting element voltage volts
TCR ppm/° C
Isolation voltage volts
Resistance tolerance %
Thermal impedance ° C/watt
Ambient temperature range ° C
<
1Ω : 5
<
>1Ω : 1, 2, 5
6.2
+0 -0.5
2.5
+0 -0.25
9.0
+0 -0.6
3.6
+0.5 -0
12.5
+0 -2.1
4.2
+0.8 -0
14.5
+0.6 -0
5.3
+0 -0.4
d
+0.01 -0.06
L D
Power Metal
Film Resistors
MF-S Series
Small size for power rating
Range of 4 sizes: 0.5 watt to 3 watt at 70˚C
Flameproof protection
MF1/2S MF1S MF2S MF3S
Standard values
Power rating at 70° C watts 0.5 1.0 2.0 3.0
0R1 – 1M
500
140 110 80 60
-55 to 155
700
350
< 10Ω :350 10Ω :150
E24 preferred
General Note
Welwyn Components reserves the right to make changes in product specification without notice or liability.
All information is subject to Welwyn’s own data and is considered accurate at time of going to print.
© Welwyn Components Limited · Bedlington, Northumberland NE22 7AA, UK
Telephone: +44 (0) 1670 822181 · Facsimile: +44 (0) 1670 829465 · Email: info@welwyn-tt.com · Website: www.welwyn-tt.com
Electrical Data
Issue C · 01.06
A subsidiary of
TT electronics plc
Welwyn Components
147
Dimensions (mm) & Weight (g)
PCB Min.
mounting
bend
Type L Mx D Max f min d nom centres radius Wt.nom
MF1/2S 21.0 0.6 1.02 0.6 0.3
MF1S 19.6 0.8 12.7 1.2 0.5
MF2S 17.8 0.8 18.4 1.2 0.9
MF3S 23.8 0.8 20.3 1.2 1.1
Physical Data
L
Df
d
10.2
03.08
Resistance range ohms
Limiting element voltage volts
TCR ppm/° C
Isolation voltage volts
Resistance tolerance %
Thermal impedance ° C/watt
Ambient temperature range ° C
<
1Ω : 5
<
>1Ω : 1, 2, 5
6.2
+0 -0.5
2.5
+0 -0.25
9.0
+0 -0.6
3.6
+0.5 -0
12.5
+0 -2.1
4.2
+0.8 -0
14.5
+0.6 -0
5.3
+0 -0.4
d
+0.01 -0.06
L D
Power Metal
Film Resistors
MF-S Series
www.bitechnologies.com www.irctt.com www.welwyn-tt.com
General Note
TT electronics reserves the right to make changes in product specification without notice or liability.
All information is subject to TT electronics’ own data and is considered accurate at time of going to print.
© TT electronics plc
01.13
Flameproof Power
Metal Film Resistors
MF-S Series
© Welwyn Components Limited Bedlington, Northumberland NE22 7AA, UK
Telephone: +44 (0) 1670 822181 · Facsimile: +44 (0) 1670 829465 · Email: info@welwyn-tt.com · Website: www.welwyn-tt.com Issue C · 01.06
Welwyn Components
148
Application Notes
1. If the resistors are to dissipate full rate 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. Lead Formed resistors can also be supplied. Standard
options of Lancet, Radial and Goalpost forming are shown
in lead Form Information section. b
f1f2
66
c
Body location f 1 – f 2 1.4 mm
Figure 1
Packaging
The preferred method of packaging is taped and ammo
packed, see figure 1 for critical dimensions.
Alternative packaging is available by special request.
Marking
MF Series resistors are colour coded with 5 bands for 1%
tolerance or 4 bands for other tolerances. IEC 62 colours
are used.
Solvent Resistance
The body protection and marking are resistant to all normal
industrial cleaning solvents suitable for printed circuits.
Flammability
The resistors will not burn or emit incandescent particles
under any condition of applied temperature or power
overload.
Construction
The resistance element is a precisely controlled thin film of
metal alloy on a high purity ceramic core, protected by a
cement coating applied so that terminations remain
completely clear.
This permits a well defined body length, (clean lead to clean
lead dimension L).
Terminations
Material Solder-coated copper wire.
Strength The terminations meet the requirements of
IEC 68.2.21
Solderability The terminations meet the requirements of
IEC 115-1, Clause 4.17.3.2
Maximum
Load: 1000 hours at 70˚C 5%R
Shelf life: 12 months at room temperature 1%R
Derating from rated power at 70˚C C˚551taorez%R
Climatic 1%R
Climatic category 40/125/56
Temperature rapid change 5.0%R
Resistance to solder heat 5.0%R
Performance Data
03.08
cbepyT
MF1/2S52 2 5 0.5
5 0.5
5 0.5
10 0.5
52 2
52 2
67 2
MF1S
MF2S
MF3S
Power Metal
Film Resistors
MF-S Series
www.bitechnologies.com www.irctt.com www.welwyn-tt.com
General Note
TT electronics reserves the right to make changes in product specification without notice or liability.
All information is subject to TT electronics’ own data and is considered accurate at time of going to print.
© TT electronics plc
01.13
Flameproof Power
Metal Film Resistors
MF-S Series
© Welwyn Components Limited Bedlington, Northumberland NE22 7AA, UK
Telephone: +44 (0) 1670 822181 · Facsimile: +44 (0) 1670 829465 · Email: info@welwyn-tt.com · Website: www.welwyn-tt.com Issue C · 01.06
Welwyn Components
148
03.08
Ordering Procedure
Example: MF3S at 3.3 kilohms and 5% tolerance in ammo pack box of 1000 pieces –
M F 3 S – 3 K 3 J I
Type
Value (use IEC62 code)
Tolerance (use IEC62 code)
F
1%
J
5%
G
2%
Packing
Ammo
MF1/2S
5000/box
Standard
MF1S
2500/box
MF2S
1500/box
MF3S
1000/box