High Voltage

Planar Dividers

4530 Series

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Issue B · 03.02

Welwyn Components

208

Application Notes

The terminations should not be bent closer than 1.5mm from

the body, and the recommended minimum bend radius is 1mm.

Due to the high voltage which can appear between the resistor

body and any adjacent metal part, resistors should be mounted

at an adequate distance from other conducting parts.

Temperature Category

Lower temperature category is -55°C, upper temperature

category is 125°C. Due to the possibility of surface

condensation it is recommended that high voltage is not

applied to resistors in conditions of high humidity.

Design Flexibility

The experience of Welwyn engineers has been used to design

this generation of high voltage planar resistors to be suitable

for a majority of applications. However, should an application

require particular consideration, Welwyn designers are

available to provide advice and where applicable, to

recommend a non-standard product. Special sizes, designs

etc, can be prototyped at short notice.

Non Standard Optional Features

The options listed below are some of the special features

which may be provided, subject to agreement.

Special substrate size.

Leadless version with palladium silver solder pads.

Special termination length, diameter and pitch.

Special designs for pulse applications.

Resistance value outside stated range.

Multiple dividers R1, R2, R3 etc.

Packaging

Packed in foam within a box.

Construction

A high quality alumina substrate is printed with a specially

selected high voltage resistor ink based on a ruthenium

oxide/glass system. A choice of protective systems is available.

Choice of Protection

As standard components are supplied conformally coated

with an epoxy resin. By special request components can be

supplied unprotected or with a screen printed epoxy

‘handling’ protection.

Terminations

Material

Solder-coated phosphor bronze lead-frame or

0.8mm dia, copper wire leads.

Solderability

Meets the requirements of IEC 115-1, Clause

4.17.3.2.

Marking

Legend marked with type reference, resistance value,

tolerance ratio and manufacturing date code.

5th digit:

1 refers to leadframe

2 refers to copper wire lead

6th digit:

2 refers to conformal coating

3 refers to screen printed protection

4 refers to unprotected components

Solvent Resistance

The marking and protection will withstand all commonly used

industrial cleaning solvents.

Maximum

Typical

Load: 1000 hours at 70°C

∆R%

5

0.3

Derating from rated power at 70°C

Zero at 125°C

Shelf life: 12 months at room temperature

∆R%

0.3

< 0.1

Temperature rapid change

∆R%

0.1

0.02

Resistance to solder heat

∆R%

0.05

0.02

4531, 4532

5

< 3

Voltage coefficient of resistance ppm/volt

4533, 4534

3

< 2

4535, 4536, 4537

1.5

< 1

Performance Data