On 16/03/2016 17:48, The Natural Philosopher wrote:
On 16/03/16 17:17, Clive George wrote:
On 16/03/2016 16:55, The Natural Philosopher wrote:
On 16/03/16 15:36, Dave Liquorice wrote:
On Wed, 16 Mar 2016 01:14:21 -0700 (PDT), wrote:

Well happyish, after a few hours the transformer started to make
gentle frying noises, smell and be rather hot. Nothing else was
overly hot. Electrically leaking electrolytics would run hot
wouldn't
they?

Just depends how leaky they are. Often not.

Having let it cool down overnight I powered it up again this morning.
Started to make noises within 10 mins, brightness faded and display
became pin chusion / barrel distorted. Transformer hot and blank bit
of PCB that has a double 0.25uF 1500 VDC smoothing capacitor for the
-1000 V rail behind it was warm...

Have you looked at the price of 0.25uF 1500 VDC capacitors? First
hits I got where £50 each. NOS on ebay from the eastern block
countries are around USD30....

My inexpert eye cast over the datasheet tells me that a couple of
these might survive the
ripple.

http://www.digikey.co.uk/product-det...338-1167-ND/80
9460

0.22uf 1600 VDC £4.35 each but digikey want £12.00 shipping, mouser
cheaper but £12 shipping again. Element 14 £10 each plus shipping
from across the pond...

Blimey. I used to use those things and they were around 60p each.

here ya go. £2.69 each and nice polypropylenes

http://uk.farnell.com/kemet/phe845vy6220mr30l2/cap-film-pp-0-22uf-760vac-rad/dp/2456435?CMP=KNC-GUK-GEN-SHOPPING-KEMET&CAGPSPN=pla&gross_price=true&gclid=CIP6t8bVx csCFfMV0wodNaEEVw&mckv=riKTiWxl_dc|pcrid|781083779 49|&CAWELAID=120173390001549446



760v on a 1000v rail?

1500V DC. 760v AC

Fair enough :-)

On Wed, 16 Mar 2016 16:55:06 +0000, The Natural Philosopher wrote:


http://www.digikey.co.uk/product-det...338-1167-ND/80

9460

0.22uf 1600 VDC £4.35 each but digikey want £12.00 shipping,
mouser
cheaper but £12 shipping again. Element 14 £10 each plus
shipping
from across the pond...

Blimey. I used to use those things and they were around 60p each.

here ya go. £2.69 each and nice polypropylenes

http://uk.farnell.com/kemet/phe845vy6220mr30l2/cap-film-pp-0-22uf-760vac-rad/dp/2456435?CMP=KNC-GUK-GEN-SHOPPING-KEMET&CAGPSPN=pla&gross_price=true&gclid=CIP6t8bVx csCFfMV0wodNaEEVw&mckv=riKTiWxl_dc|pcrid|781083779 49|&CAWELAID=120173390001549446

Odd I follow that link and I get £1.27 each but I notice that it's
really a safety rated supression capacitor. But it has lead me
to:

http://uk.farnell.com/kemet/phe450rd...-film-pp-0-22u
f-1-6kv/dp/2495752

£2.99 but designed for SMPSUs TVs etc better able to handle the
ripple in a PSU?

--
Cheers
Dave.

On Tue, 15 Mar 2016 13:04:55 -0700 (PDT), jkn wrote:

North Pennines, hmm. I am on the South Coast ...

You should have mail, at least I've not had a bounce or a message
telling me it's still in the queue.

--
Cheers
Dave.

On 16/03/16 20:41, Dave Liquorice wrote:
On Wed, 16 Mar 2016 16:55:06 +0000, The Natural Philosopher wrote:


http://www.digikey.co.uk/product-det...338-1167-ND/80

9460

0.22uf 1600 VDC £4.35 each but digikey want £12.00 shipping,
mouser
cheaper but £12 shipping again. Element 14 £10 each plus
shipping
from across the pond...

Blimey. I used to use those things and they were around 60p each.

here ya go. £2.69 each and nice polypropylenes

http://uk.farnell.com/kemet/phe845vy6220mr30l2/cap-film-pp-0-22uf-760vac-rad/dp/2456435?CMP=KNC-GUK-GEN-SHOPPING-KEMET&CAGPSPN=pla&gross_price=true&gclid=CIP6t8bVx csCFfMV0wodNaEEVw&mckv=riKTiWxl_dc|pcrid|781083779 49|&CAWELAID=120173390001549446

Odd I follow that link and I get £1.27 each but I notice that it's
really a safety rated supression capacitor. But it has lead me
to:

http://uk.farnell.com/kemet/phe450rd...-film-pp-0-22u
f-1-6kv/dp/2495752

£2.99 but designed for SMPSUs TVs etc better able to handle the
ripple in a PSU?

Don't think you will have any issues at all with a non elecrolytic on
ripple rating. Suppression caps need to work at RF so they have very
good ESR at highish frequencies.


--
New Socialism consists essentially in being seen to have your heart in
the right place whilst your head is in the clouds and your hand is in
someone else's pocket.

On 14/03/2016 15:40, Dave Liquorice wrote:
My trusty Telequipment Serviscope S51A has decided it doesn't want to
play after being in the (dry) loft for cough years. On initial
power and warm up it did work apart from the X shift. Turned me back
to three seconds and the trace disappeared and the normal combination
of Y and X shift can't locate, even reflection/scattering, of the
beam. B-( Reseated all the valves but to avail, they all glow
nicely though.

Yes it's an antique but served my purposes well but I suspect it's
going to need extensive fault finding. So I'm thinking that a decent
budget modern 'scope is on the cards. Not looking for anything
special The S51A only went up to 3 Mc/s and maximum of 1 uSec/cm.

Anyone got recommends/avoids for makers or models?

If you can live with audio and moderate ultrasonic frequencies only then
the software Daqarta (sp?) is hard to beat for turning a PC soundcard
into a two channel oscilloscope/spectrum analyser and signal generator
(the latter works forever even if you don't register it).

http://www.daqarta.com/

No connection with the guy - only a satisfied user. It is great for
displaying a live music signal to an audience for demos.

The only risk is connecting your PCs soundcard to the DUT.

--
Regards,
Martin Brown

In article , says...

On 14/03/2016 15:40, Dave Liquorice wrote:

Anyone got recommends/avoids for makers or models?


I bought one of these recently - http://www.ebay.co.uk/itm/291559198787
seems reasonable for the price, albeit I hadn't used a scope for nearly
as long as yours was in your loft, and even then I only had need of one
very occasionally.


or, if you don't need the logic analyser option, save £15 with this version:

http://www.ebay.co.uk/itm/HANTEK-602...igital-Storag-
Oscilloscope-2-Channels-20MHz-48MSa-s-/271543870829?hash=item3f3946a56d

--

Terry

---
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