WRM Datasheet, PDF (1/3 Pages) Welwyn Components Limited – Mini Melf Resistors

Mini Melf
Resistors
WRM Series
• High reliability
• ^{Predictable pulse handling capability}
• ^{Tolerances down to 0.1%}
• ^{TCR down to 5 ppm/°C}
Welwyn Components
Electrical Data
Power rating at 70°C
Resistance range
Limiting element voltage
TCR
Resistance tolerance
Standard values
Thermal impedance
Ambient temperature range
Insulation resistance
Physical Data
Dimensions (mm) and weight (g)
Type
L
D
max
max
WRM 0102
2.2
1.1
WRM 0204
3.6
1.4
WRM 0207
6.0
2.2
watts
ohms
volts
ppm/°C
%
k/W
°C
ohms
WRM 0102
0.2
R22 – 2M21
150
15, 25, 50
250
WRM 0204
0.25
R22 – 10M
200
5, 15, 25, 50
0.1, 0.25, 0.5, 1.0, 2, 5
E24 & E96
200
-55 to +125
>10¹⁰
WRM 0207
0.4
R22 – 8M2
250
25, 50
140
D¹
K
Weight
max
min
1.1
0.35
0.01
1.4
0.5
0.02
2.2
1.1
0.08
L
D₁
D
L¹ K
Construction
A metal film is deposited onto a high dissipation ceramic
former to which tin plated teminating caps are fitted.
The resistor is adjusted to value by a helical cut in the film
and the body is protected by a lacquer coating.
Marking
Resistance values are colour coded with 4 or 5 bands
depending on type.
Terminations
Material
Plated steel cap.
Solderability The pure tin finish produces ageing free
contacts on which low melting solders can
be used. Dipped area shall be covered with
a smooth and bright solder coating after
3 seconds immersion at 215°C.
Solvent Resistance
The body protection and marking are resistant to all normal
industrial cleaning solvents suitable for printed circuit boards.
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: [phone] · Facsimile: [phone] · Email: [e-mail] · Website: www.welwyn-tt.com
A subsidiary of
TT electronics plc
Issue D · 09.06