From Japanese SMPS, looks like regular 1A rectifier diode. Labeled B320219
(the "02" is larger type than the others).

Can't find cross-reference. Any help would be greatly appreciated.

Thanks,
--
DaveC

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DaveC wrote:
From Japanese SMPS, looks like regular 1A rectifier diode. Labeled B320219
(the "02" is larger type than the others).

Can't find cross-reference. Any help would be greatly appreciated.

Any chance of reverse-engineering the bit of the circuit it is used in,
and producing a bit of a circuit diagram?

--
Sue

Palindr?me wrote:

DaveC wrote:
From Japanese SMPS, looks like regular 1A rectifier diode. Labeled B320219
(the "02" is larger type than the others).

Can't find cross-reference. Any help would be greatly appreciated.

Any chance of reverse-engineering the bit of the circuit it is used in,
and producing a bit of a circuit diagram?

It's probably not too tricky to acertain it's likely rating and speed by
judicious examination of where it lies in the gubbins.

Graham

Thus spake Palindr˜»me:

Any chance of reverse-engineering the bit of the circuit it is used in, and
producing a bit of a circuit diagram?

Not very good at this... just a component-test monkey (c:

But it (and its partner) seems to be across a c.t. winding of the SMPS
transformer. Electrolytic filter caps "downstream" from these are rated at
25v.

There are a dozen more of this type of diode in this SMPS, across other
trans. windings.

This is a multiple-voltage ps inside a 240v ac motor controller in a Japanese
printing press.

Thanks,
--
DaveC

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"DaveC" wrote in message
news.net...
Thus spake Palindr~»me:

Any chance of reverse-engineering the bit of the circuit it is used in,
and
producing a bit of a circuit diagram?

Not very good at this... just a component-test monkey (c:

But it (and its partner) seems to be across a c.t. winding of the SMPS
transformer. Electrolytic filter caps "downstream" from these are rated at
25v.

There are a dozen more of this type of diode in this SMPS, across other
trans. windings.

This is a multiple-voltage ps inside a 240v ac motor controller in a
Japanese
printing press.

Thanks,
--
DaveC

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If it's on the secondary side, it will not be a 'normal' 1A diode. It will
be a high speed Schottky type. If you try to use a standard silicon
rectifier diode, it will run very hot and fail, in short order.

Arfa

"DaveC" wrote in message
news.net...
From Japanese SMPS, looks like regular 1A rectifier diode. Labeled B320219
(the "02" is larger type than the others).

Can't find cross-reference. Any help would be greatly appreciated.

Thanks,
--
DaveC

This is an invalid return address
Please reply in the news group


If testing it shows slight reverse leakage - it could be a Shottky-barrier
type, Most DMMs have a diode forward voltage test if the Vf is less than
about 0.4V and more than 0.1V it almost certainly is SB, if its glass
encapsulated - consider the possibility it's a zener, these show Vf about
0.7V, regular diodes show about 0.6V and fast silicon types usually
somewhere around 0.55V.

But if any of these tests pass - it's probably OK anyway!

Thus spake ian field:

If testing it shows slight reverse leakage - it could be a Shottky-barrier
type, Most DMMs have a diode forward voltage test if the Vf is less than
about 0.4V and more than 0.1V it almost certainly is SB, if its glass
encapsulated - consider the possibility it's a zener, these show Vf about
0.7V, regular diodes show about 0.6V and fast silicon types usually somewhere

around 0.55V.

The other diode ("good" one) in the circuit measures 0.4v in DMM diode test
(Fluke meter). Not glass, epoxy (black stuff).

But if any of these tests pass - it's probably OK anyway!

Infinite both directions, according to diode test on the DMM.

Is SB type used as rectifier in SMPS? Or is vanilla Schottky used in this
application?

Thanks,
--
DaveC

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"DaveC" wrote in message
news.net...
Thus spake ian field:

If testing it shows slight reverse leakage - it could be a
Shottky-barrier
type, Most DMMs have a diode forward voltage test if the Vf is less than
about 0.4V and more than 0.1V it almost certainly is SB, if its glass
encapsulated - consider the possibility it's a zener, these show Vf about
0.7V, regular diodes show about 0.6V and fast silicon types usually
somewhere

around 0.55V.

The other diode ("good" one) in the circuit measures 0.4v in DMM diode
test
(Fluke meter). Not glass, epoxy (black stuff).

But if any of these tests pass - it's probably OK anyway!

Infinite both directions, according to diode test on the DMM.

Is SB type used as rectifier in SMPS? Or is vanilla Schottky used in this
application?

Thanks,
--
DaveC

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Is "the other one" with 0.4Vf identical to the one you've taken out?

Thus spake ian field:

Is "the other one" with 0.4Vf identical to the one you've taken out?

Yes, same markings. They're apparently a backward-connected set of rectifiers
across a SMPS ct transformer secondary.

Thanks,
--
DaveC

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DaveC wrote:

Thus spake Palindr˜»me:

Any chance of reverse-engineering the bit of the circuit it is used in, and
producing a bit of a circuit diagram?

Not very good at this... just a component-test monkey (c:

But it (and its partner) seems to be across a c.t. winding of the SMPS
transformer. Electrolytic filter caps "downstream" from these are rated at
25v.

You mean the anode ( or cathode ) of the diode is directly connected to a
reservoir cap ? It'll be a rectifier on the secondary side. It needs to be a high
speed type and from your mention of 25V, I'd probably use a 200V part ( for
safety's sake ). Current rating - you say it looks like 1A - would suggest a
UF4003 replacement. Are you sure about the current rating though ?
http://www.chipdocs.com/datasheets/d...CC/UF4001.html

Graham

Arfa Daily wrote:

"DaveC" wrote in message
news.net...
Thus spake Palindr~»me:

Any chance of reverse-engineering the bit of the circuit it is used in,
and
producing a bit of a circuit diagram?

Not very good at this... just a component-test monkey (c:

But it (and its partner) seems to be across a c.t. winding of the SMPS
transformer. Electrolytic filter caps "downstream" from these are rated at
25v.

There are a dozen more of this type of diode in this SMPS, across other
trans. windings.

This is a multiple-voltage ps inside a 240v ac motor controller in a
Japanese
printing press.

Thanks,
--
DaveC

This is an invalid return address
Please reply in the news group

If it's on the secondary side, it will not be a 'normal' 1A diode. It will
be a high speed Schottky type.

Not necessarily Shottky actually. ( btw - is it *meant* to have a 'c' in it or
not ? )

If you try to use a standard silicon
rectifier diode, it will run very hot and fail, in short order.

Oh I don't know. A subcontractor once fitted a 1N4004 where I'd specified a
UF4004 on a lightly loaded secondary. It ran for many hours before failing !

They did it second time round too ! I reckon that purchasing looked at the part
number and reckoned they could substitute. Lovely stuff working with Asians.

Funny thing was, my colleagues looked glum since it was our first smps design. I
( in my infinite wisdom ! ) smelt a rat and went to it almost straight off. It
was shorted. Just made the thing go into hiccup mode.

Graham

Thus spake Pooh Bear:

http://www.chipdocs.com/datasheets/d...CC/UF4001.html

(That's a paid-subscription link...)

Re. the current rating, I'm just comparing the unit in question with a
non-schottky, vanilla 1A rectifier. They are similar in size.

Thanks,
--
DaveC

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DaveC wrote:

Thus spake ian field:

If testing it shows slight reverse leakage - it could be a Shottky-barrier
type, Most DMMs have a diode forward voltage test if the Vf is less than
about 0.4V and more than 0.1V it almost certainly is SB, if its glass
encapsulated - consider the possibility it's a zener, these show Vf about
0.7V, regular diodes show about 0.6V and fast silicon types usually somewhere

around 0.55V.

The other diode ("good" one) in the circuit measures 0.4v in DMM diode test
(Fluke meter). Not glass, epoxy (black stuff).

But if any of these tests pass - it's probably OK anyway!

Infinite both directions, according to diode test on the DMM.

Is SB type used as rectifier in SMPS? Or is vanilla Schottky used in this
application?

SB = Shottky barrier. Techy speak for 'shottky'.

Graham

DaveC wrote:

Thus spake Pooh Bear:

http://www.chipdocs.com/datasheets/d...CC/UF4001.html

(That's a paid-subscription link...)


Yabbut.... It gave a list of UF400x devices which I didn't find anywhere else
quickly. You can get the data easily with a bit of common sense. Oh sod it.....
http://www.fairchildsemi.com/pf/UF/UF4003.html get the pdf

Re. the current rating, I'm just comparing the unit in question with a
non-schottky, vanilla 1A rectifier. They are similar in size.

I ask for a reason. Do you know the current draw on the supply ? It pays to fit
a beefier device if unsure.

Graham

DaveC wrote:
Thus spake Pooh Bear:


http://www.chipdocs.com/datasheets/d...CC/UF4001.html


(That's a paid-subscription link...)

Re. the current rating, I'm just comparing the unit in question with a
non-schottky, vanilla 1A rectifier. They are similar in size.

The thickness of the wires coming out is often a better indication than
the size of the body.

IIUC, you aren't going into production with this thing, just trying to
get it working. So you can afford to err on the side of safety and put
in a well over-spec'ed schottky, even though a much lower spec'ed (i.e.
lot cheaper) device would be fine too.

Any idea why it failed?

--
Sue

Thus spake Palindr˜»me:

Any idea why it failed?

Nope. There are 4 identical controllers. They've all been purring along for
near 10 years without a hiccup.
--
Please, no "Go Google this" replies. I wouldn't
ask a question here if I hadn't done that already.

DaveC

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Thus spake Pooh Bear:

SB = Shottky barrier. Techy speak for 'shottky'.

Not to get too bogged down in terminology, but
sb = schottky barrier = schottky ?

Thanks,
--
DaveC

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Please reply in the news group

Thus spake Pooh Bear:

I ask for a reason. Do you know the current draw on the supply ? It pays to
fit a beefier device if unsure.

Like this?:
http://www.nteinc.com/specs/500to599/pdf/nte580.pdf

I need it today and nte is the only maker available locally over-the-counter.


Thanks,
--
DaveC

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DaveC wrote:

Thus spake Palindr˜»me:

Any idea why it failed?

Nope. There are 4 identical controllers. They've all been purring along for
near 10 years without a hiccup.

Stuff gives up after a while sometimes !

Graham

DaveC wrote:

Thus spake Pooh Bear:

SB = Shottky barrier. Techy speak for 'shottky'.

Not to get too bogged down in terminology, but
sb = schottky barrier = schottky ?

Yes. The barrier bit is optional if you like. It's about the junction inside the
device. Like pn junctions. Except this one is a barrier. If one cares to be
verbose, ordinary silicon diodes could be called junction diodes.

Graham

DaveC wrote:

Thus spake Pooh Bear:

I ask for a reason. Do you know the current draw on the supply ? It pays to
fit a beefier device if unsure.

Like this?:
http://www.nteinc.com/specs/500to599/pdf/nte580.pdf

I need it today and nte is the only maker available locally over-the-counter.

That ought to do it !

Who *are* these NTE ppl anyway ?

OH ! On account of it being a CT winding, you should also replace it's 'friend'
on the other half with the same type really.

Graham

"DaveC" wrote in message
news.net...
Thus spake ian field:

Is "the other one" with 0.4Vf identical to the one you've taken out?

Yes, same markings. They're apparently a backward-connected set of
rectifiers
across a SMPS ct transformer secondary.

Thanks,
--
DaveC

This is an invalid return address
Please reply in the news group


The 0.4Vf likely suggests a SB diode

"Pooh Bear" wrote in message
...

Arfa Daily wrote:

"DaveC" wrote in message
news.net...
Thus spake Palindr~»me:

Any chance of reverse-engineering the bit of the circuit it is used
in,
and
producing a bit of a circuit diagram?

Not very good at this... just a component-test monkey (c:

But it (and its partner) seems to be across a c.t. winding of the SMPS
transformer. Electrolytic filter caps "downstream" from these are rated
at
25v.

There are a dozen more of this type of diode in this SMPS, across other
trans. windings.

This is a multiple-voltage ps inside a 240v ac motor controller in a
Japanese
printing press.

Thanks,
--
DaveC

This is an invalid return address
Please reply in the news group

If it's on the secondary side, it will not be a 'normal' 1A diode. It
will
be a high speed Schottky type.

Not necessarily Shottky actually. ( btw - is it *meant* to have a 'c' in
it or
not ? )


Yeah, OK, it may well not actually be a diode with Schottky barrier
topology. I was using the term in a service engineer's generic way to
indicate a high speed fast recovery diode, as opposed to a low speed
grunting silicon junction diode - the OP's 'normal' diode that he speaks
of.

And yes, being named after German physicist Walter H Schottky, there is a "
c " in it ...


If you try to use a standard silicon
rectifier diode, it will run very hot and fail, in short order.


Oh I don't know. A subcontractor once fitted a 1N4004 where I'd specified
a
UF4004 on a lightly loaded secondary. It ran for many hours before failing
!

They did it second time round too ! I reckon that purchasing looked at the
part
number and reckoned they could substitute. Lovely stuff working with
Asians.

Funny thing was, my colleagues looked glum since it was our first smps
design. I
( in my infinite wisdom ! ) smelt a rat and went to it almost straight
off. It
was shorted. Just made the thing go into hiccup mode.

Graham


I reckon that the key to this one is that it was lightly loaded. A 1N4004
certainly won't stand up to SMPS frequencies for long, if loaded to more
than a few tens of mA. In fact I think you were very lucky that it did stand
up to it for as long as you say. Even the proper article fail regularly. I
change many secondary rectifiers that have failed short circuit in DVD
player switchers. Anyway, whatever. I stand by my original reply that the
diode will not be a 'standard' silicon one, and the fitting of a standard
one would likely result in short order re-failure.

Arfa