Welwyn Panclimatic Resistors - UK Vintage Radio Repair and Restoration Discussion Forum

M0FYA Andy · 4th Dec 2010, 11:53 am

Has anyone got any information on the Welwyn series of "Panclimatic" resistors, ideally a Welwyn datasheet or catalogue?

They are usually seen in test equipment, but as I have quite a lot I'm wondering about using them for more general applications.
They come in a range of physical sizes, it would be useful to know the power and voltage rating of each size.
On some it is possible to see a spiral under the black paint - are they a carbon film type of construction?

Thanks for any help,
Andy

ronbryan · 4th Dec 2010, 12:59 pm

Andy

The High Stability Panclimatic Protected (to DEF-5112) C20 series are:-

Type, Rating at 70C, Limiting Voltage.
C20 0.125W, 200V
C21 0.25W, 250V
C22 0.5W, 350V
C23 0.75W, 500V
C24 1.0W, 800V
C25 2.0W, 1500V

C13 1.0W, 800V
C14 2.0W, 1600V

All are humitity class H6

The resistive element is a pyrolitic carbon film deposited on to a high ceramic rod. The desired resistance is obtained by cutting a helical groove through the film.

Welwyn Electric Catalogue 1970-71, pages 40 and 41

Ron

M0FYA Andy · 4th Dec 2010, 2:32 pm

Ron,
Thanks for that, some very useful information.

Has anyone got experience of using this type for general use? I imagine they are a bit inductive for RF use, but should be fine for audio?

Andy

Graeme Murphy · 7th Dec 2010, 12:14 am

No experience of using/making them but I do work for said employer !
I can remember these being made when I started work way back in the late 1970's. A rather expensive component if I remember rightly.

glowinganode · 9th Dec 2010, 12:05 am

Here are some from stock, the second one down is a C22. None of the others are marked, but I can probably work out which is which.
Also a Salmon pink version and a Painton device both of identical size (and power dissipation I assume) the the one above.
Rob.

M0FYA Andy · 9th Dec 2010, 8:37 am

Does the black or salmon pink paint imply a different range with different characteristics? I usually associate pink resistors with high stability types, but I assume the black ones are also high stability as they were used extensively in test equipment.

Andy

Graeme Murphy · 13th Apr 2011, 12:43 pm

Catalogue found !
I will post the data tonight.

Graeme Murphy · 13th Apr 2011, 11:21 pm

As promised, this data is reproduced from the product catalogue of Welwyn Electric Limited 1968-1969.

M0FYA Andy · 14th Apr 2011, 7:11 am

Very useful data!
Many thanks,
Andy

4th Dec 2010, 11:53 am	#1
M0FYA Andy Nonode Join Date: May 2007 Location: Preston, Lancashire, UK. Posts: 2,511	Welwyn Panclimatic Resistors Has anyone got any information on the Welwyn series of "Panclimatic" resistors, ideally a Welwyn datasheet or catalogue? They are usually seen in test equipment, but as I have quite a lot I'm wondering about using them for more general applications. They come in a range of physical sizes, it would be useful to know the power and voltage rating of each size. On some it is possible to see a spiral under the black paint - are they a carbon film type of construction? Thanks for any help, Andy

4th Dec 2010, 12:59 pm	#2
ronbryan Octode Join Date: Jan 2003 Location: Guildford, Surrey, UK. Posts: 1,959	Re: Welwyn Panclimatic Resistors Andy The High Stability Panclimatic Protected (to DEF-5112) C20 series are:- Type, Rating at 70C, Limiting Voltage. C20 0.125W, 200V C21 0.25W, 250V C22 0.5W, 350V C23 0.75W, 500V C24 1.0W, 800V C25 2.0W, 1500V C13 1.0W, 800V C14 2.0W, 1600V All are humitity class H6 The resistive element is a pyrolitic carbon film deposited on to a high ceramic rod. The desired resistance is obtained by cutting a helical groove through the film. Welwyn Electric Catalogue 1970-71, pages 40 and 41 Ron

4th Dec 2010, 2:32 pm	#3
M0FYA Andy Nonode Join Date: May 2007 Location: Preston, Lancashire, UK. Posts: 2,511	Re: Welwyn Panclimatic Resistors Ron, Thanks for that, some very useful information. Has anyone got experience of using this type for general use? I imagine they are a bit inductive for RF use, but should be fine for audio? Andy

7th Dec 2010, 12:14 am	#4
Graeme Murphy Tetrode Join Date: Oct 2009 Location: Blyth, Northumberland, UK. Posts: 62	Re: Welwyn Panclimatic Resistors No experience of using/making them but I do work for said employer ! I can remember these being made when I started work way back in the late 1970's. A rather expensive component if I remember rightly.

9th Dec 2010, 12:05 am	#5
glowinganode Octode Join Date: Apr 2009 Location: Aylesbury, Buckinghamshire, UK. Posts: 1,522	Re: Welwyn Panclimatic Resistors Here are some from stock, the second one down is a C22. None of the others are marked, but I can probably work out which is which. Also a Salmon pink version and a Painton device both of identical size (and power dissipation I assume) the the one above. Rob. Attached Thumbnails __________________ We have done so much, for so long, with so little, we are now qualified to do anything with nothing.

9th Dec 2010, 8:37 am	#6
M0FYA Andy Nonode Join Date: May 2007 Location: Preston, Lancashire, UK. Posts: 2,511	Re: Welwyn Panclimatic Resistors Does the black or salmon pink paint imply a different range with different characteristics? I usually associate pink resistors with high stability types, but I assume the black ones are also high stability as they were used extensively in test equipment. Andy

13th Apr 2011, 12:43 pm	#7
Graeme Murphy Tetrode Join Date: Oct 2009 Location: Blyth, Northumberland, UK. Posts: 62	Re: Welwyn Panclimatic Resistors Catalogue found ! I will post the data tonight.

13th Apr 2011, 11:21 pm	#8
Graeme Murphy Tetrode Join Date: Oct 2009 Location: Blyth, Northumberland, UK. Posts: 62	Re: Welwyn Panclimatic Resistors As promised, this data is reproduced from the product catalogue of Welwyn Electric Limited 1968-1969. Attached Thumbnails

14th Apr 2011, 7:11 am	#9
M0FYA Andy Nonode Join Date: May 2007 Location: Preston, Lancashire, UK. Posts: 2,511	Re: Welwyn Panclimatic Resistors Very useful data! Many thanks, Andy