Weir 413 - Circuit diagram - UK Vintage Radio Repair and Restoration Discussion Forum

mark_in_manc · 21st Apr 2013, 8:42 am

hi Folks

I have a Weir 413 0-30v PSU with a fault. I found some info on this thread

https://www.vintage-radio.net/forum/showthread.php?t=56278

but the circuit diagram here, though having some similarities to my unit, is not the same - mine is all discretes, no op amps.

I wonder if anyone has any other info on these? I have two - the 413D (-15 0 +15v) works, but the 413 (0 30v) does not, so info on the latter would be especially useful.

Thanks
Mark

Radio Wrangler · 21st Apr 2013, 8:54 am

That peculiar graphical representation of pushbutton combinations is something I've seen before. It's on a Marconi supply of about the same size at work.

It's earlier than those Weir units, but very similar. Don't have any info on it, just a supply bought in an ex-government (think of it as a tax refund) lot.

I wonder if Weir took over the designs from Marconi, and later modernised them? If so, you might find info on your unit by searching for Marconi Instruments.

It's a useful low noise supply.

David

Refugee · 21st Apr 2013, 10:24 am

Look out for the connections between the terminal posts and the internal wiring.
They blow the currant limit transistor to open circuit

It is a pain getting access to the terminal posts for a repair too.

Refugee · 21st Apr 2013, 10:27 am

I did not get any further than you when looking for the circuit diagram.

Dickie · 21st Apr 2013, 10:33 am

Marconi Instruments originally badge-engineered them as TF2153, TF2154 and TF2155 and I guess when Weir updated the designs MI did not continue with them. I've got circuits and will scan them when I've got time but you might find something's already out there.

Refugee · 21st Apr 2013, 2:03 pm

It is the "D" models that we can't find the circuit diagrams for. They may well be later than the Marconi models. They are the ones with center zero outputs for OP amps and so on.
I had to work without a manual in order to fix mine.

mark_in_manc · 21st Apr 2013, 5:25 pm

Richard - I'd very much appreciate that. I've found versions on the web for sale, so a scan would obviously help me out a lot. No rush!
Thanks
Mark

mark_in_manc · 22nd Apr 2013, 1:09 pm

...well, I did the sensible thing and went and spoke to the electrical technician in the university building outside of which I pulled my duff PSU from the skip.

A rather low-res scan is attached of the correct manual and circuit diagrams. If you really need a better one I have a good photocopy and may be able to think of a way to get one to you.

Mods - I don't think I can change the thread title. If it were possible to change it to 'Weir 403 413 423 circuit diagram', it would reflect better the information now to be found within!

cheers
Mark

Radio Wrangler · 22nd Apr 2013, 1:29 pm

I've saved a copy too to help dissuade Murphy from jinxing the one at work

Thanks,
David

Refugee · 22nd Apr 2013, 3:23 pm

Cheers for the scan Mark.

The scan is good and clear enough for information. The "D" option part was missing from the scan I had.

Dickie · 23rd Apr 2013, 8:12 pm

The Marconi version is very similar but my handbook has a sheet of component changes up to 1978 which may be of use. Sorry about the quality.

mark_in_manc · 28th Apr 2013, 2:43 pm

Oops.

The fault on my unit meant it worked OK from 0v to about 1/3 FSD, and then shot off to the full supply rail.

So I got all sorts of fancy ideas about the control circuit and probed around for ages, writing down voltages here there and everywhere.

And then I checked the 50K main pot, which was o/c about 1/3 of the way through its travel.

I had a huge 10 turn 100k pot in the box - guess I can put 100K in // with it. So now it works, with super-fancy hi-res volt setting capabilities...

21st Apr 2013, 8:42 am	#1
mark_in_manc Octode Join Date: Nov 2011 Location: Manchester, UK. Posts: 1,896	Weir 413 - Circuit diagram hi Folks I have a Weir 413 0-30v PSU with a fault. I found some info on this thread https://www.vintage-radio.net/forum/showthread.php?t=56278 but the circuit diagram here, though having some similarities to my unit, is not the same - mine is all discretes, no op amps. I wonder if anyone has any other info on these? I have two - the 413D (-15 0 +15v) works, but the 413 (0 30v) does not, so info on the latter would be especially useful. Thanks Mark

21st Apr 2013, 8:54 am	#2
Radio Wrangler Moderator Join Date: Mar 2012 Location: Fife, Scotland, UK. Posts: 23,463	Re: Weir 413 - Circuit diagram That peculiar graphical representation of pushbutton combinations is something I've seen before. It's on a Marconi supply of about the same size at work. It's earlier than those Weir units, but very similar. Don't have any info on it, just a supply bought in an ex-government (think of it as a tax refund) lot. I wonder if Weir took over the designs from Marconi, and later modernised them? If so, you might find info on your unit by searching for Marconi Instruments. It's a useful low noise supply. David __________________ Can't afford the volcanic island yet, but the plans for my monorail and the goons' uniforms are done

21st Apr 2013, 10:24 am	#3
Refugee Dekatron Join Date: Apr 2012 Location: Worksop, Nottinghamshire, UK. Posts: 5,590	Re: Weir 413 - Circuit diagram Look out for the connections between the terminal posts and the internal wiring. They blow the currant limit transistor to open circuit It is a pain getting access to the terminal posts for a repair too. Attached Thumbnails

21st Apr 2013, 10:27 am	#4
Refugee Dekatron Join Date: Apr 2012 Location: Worksop, Nottinghamshire, UK. Posts: 5,590	Re: Weir 413 - Circuit diagram I did not get any further than you when looking for the circuit diagram.

21st Apr 2013, 10:33 am	#5
Dickie Octode Join Date: Sep 2004 Location: St. Albans, Hertfordshire, UK. Posts: 1,498	Re: Weir 413 - Circuit diagram Marconi Instruments originally badge-engineered them as TF2153, TF2154 and TF2155 and I guess when Weir updated the designs MI did not continue with them. I've got circuits and will scan them when I've got time but you might find something's already out there. __________________ Regards, Richard, BVWS member

21st Apr 2013, 2:03 pm	#6
Refugee Dekatron Join Date: Apr 2012 Location: Worksop, Nottinghamshire, UK. Posts: 5,590	Re: Weir 413 - Circuit diagram It is the "D" models that we can't find the circuit diagrams for. They may well be later than the Marconi models. They are the ones with center zero outputs for OP amps and so on. I had to work without a manual in order to fix mine.

21st Apr 2013, 5:25 pm	#7
mark_in_manc Octode Join Date: Nov 2011 Location: Manchester, UK. Posts: 1,896	Re: Weir 413 - Circuit diagram Richard - I'd very much appreciate that. I've found versions on the web for sale, so a scan would obviously help me out a lot. No rush! Thanks Mark

22nd Apr 2013, 1:29 pm	#9
Radio Wrangler Moderator Join Date: Mar 2012 Location: Fife, Scotland, UK. Posts: 23,463	Re: Weir 413 - Circuit diagram I've saved a copy too to help dissuade Murphy from jinxing the one at work Thanks, David __________________ Can't afford the volcanic island yet, but the plans for my monorail and the goons' uniforms are done

22nd Apr 2013, 3:23 pm	#10
Refugee Dekatron Join Date: Apr 2012 Location: Worksop, Nottinghamshire, UK. Posts: 5,590	Re: Weir 413 - Circuit diagram Cheers for the scan Mark. The scan is good and clear enough for information. The "D" option part was missing from the scan I had.

28th Apr 2013, 2:43 pm	#12
mark_in_manc Octode Join Date: Nov 2011 Location: Manchester, UK. Posts: 1,896	Re: Weir 413 - Circuit diagram Oops. The fault on my unit meant it worked OK from 0v to about 1/3 FSD, and then shot off to the full supply rail. So I got all sorts of fancy ideas about the control circuit and probed around for ages, writing down voltages here there and everywhere. And then I checked the 50K main pot, which was o/c about 1/3 of the way through its travel. I had a huge 10 turn 100k pot in the box - guess I can put 100K in // with it. So now it works, with super-fancy hi-res volt setting capabilities...