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Inductors?*!

R

Raveninghorde

Jan 1, 1970
0
Anyone know a good supplier of off the shelf inductors?

I'm doing a battery charger design using a sepic converter. Got a daft
spec to meet of -55C storage with 0C to 45C operation.

All the specs I've checked give -40C for storage though one from
Coilcraft also gave -55C for operation??

I've tried Coiltronics, Coilcraft and Weurth.
 
P

Phil Allison

Jan 1, 1970
0
"Raveninghorde"
I'm doing a battery charger design using a sepic converter. Got a daft
spec to meet of -55C storage with 0C to 45C operation.


** Seems to me that even a well performing PSU might be damaged by
attempting to use it when its temp is -55C.

Better fit something that DISABLES the unit whenever the internal temp is
to low for safe operation - like a normally open bi-metal switch that
closes at 0C.



..... Phil
 
S

Spehro Pefhany

Jan 1, 1970
0
Not necessarily daft -- -55C storage is a pretty common mil spec
requirement; it comes from (I think) high-altitude unheated cargo bays.

The only thing that surprises me is that it isn't coupled with a -40C
operating spec, which is the usual MIL-SPEC system lower limit.

Could be limited by the battery rating.
At any rate, there should be parts out there, although they may cost $$.


Best regards,
Spehro Pefhany
 
R

Raveninghorde

Jan 1, 1970
0
Could be limited by the battery rating.



Best regards,
Spehro Pefhany

Many military batteries charge below 0C. For example Saft do some NiCd
cells which can be charged at -40C and are used in some UK batteries.

I found API Delevan do some standard inductors that will work.
Unfortunately I haven't found a coupled sepic inductor yet.
 
P

Phil Allison

Jan 1, 1970
0
"Raveninghorde"
Many military batteries charge below 0C. For example Saft do some NiCd
cells which can be charged at -40C and are used in some UK batteries.


** Kindly provide a link for that assertion - pal .

Since AFAIK it is IMPOSSIBLE to recharge a NiCd cell at a temp below
zero C.

Cos the little fuckers have got a crucial, tiny bit of water inside them
which MUST be in the liquid state.

Over to YOU ...




..... Phil
 
R

Raveninghorde

Jan 1, 1970
0
BTW pure water will supercool a surprisingly long way if it is free from
dust, but I would not want to rely on that. The electrolyte is caustic
potash which has a significantly lower freezing point.

Dissolved caustic potash depresses the freezing point of the water.
48% potassium hydroxide in aqueous solution remains liquid down to about
-11C see for example BASF datasheet.

http://www.inorganics.basf.com/p02/...Laugen)/Produktinformationen/Kalilauge#N10122
(be a miracle if that link survives)

NASA and various motorways agencies have published data of specific
NiCad batteries behaving OK in service at temperatures down to -15C.
The electrolyte must be liquid enough for ions to be mobile - when water
starts to crystallise out the remaining caustic becomes stronger and
harder to freeze so some channels remain open for conduction. I expect
irreversible damage and leaks are possible if they are hard frozen.

BTW I too doubt NiCads will charge very well at -40C.

Regards,
Martin Brown

Having checked my facts, the battery I was thinking about is specified
to charge at -31C not -40C.

I'll add no more due to commercial sensitivity.
 
P

Phil Allison

Jan 1, 1970
0
"Martin Brown Just Shat Himself "
BTW pure water will supercool a surprisingly long way if it is free from
dust, but I would not want to rely on that. The electrolyte is caustic
potash which has a significantly lower freezing point.

Dissolved caustic potash depresses the freezing point of the water.


** Who give a flying **** ?????????????

you ridiculous MASTURBATING BLOODY IDIOT !!


ALL NiCd makers warn NOT to attempt charging cells below 0C

and the FUCKING STUPID PILES OF SHIT

FUCKING EXPLODE WHEN YOU TRY !!!!!!!!!!


So go DROP DEAD

- you pathetic, ASD fucked moron !!!!!!!!!!





..... Phil
 
P

Phil Allison

Jan 1, 1970
0
"Raveninghorde"
Having checked my facts, the battery I was thinking about is specified
to charge at -31C not -40C.

I'll add no more due to commercial sensitivity.


** Why don't lying, know nothing, fucking trolling CUNTS like YOU

just go and get totally fucked ??


Eh ??



... Phil
 
M

MooseFET

Jan 1, 1970
0
Anyone know a good supplier of off the shelf inductors?

I'm doing a battery charger design using a sepic converter. Got a daft
spec to meet of -55C storage with 0C to 45C operation.

All the specs I've checked give  -40C for storage though one from
Coilcraft also gave -55C for operation??

I've tried Coiltronics, Coilcraft and Weurth.

Try www.picoelectronics.com. I used some from them many years back
that were inductors with two windings. You may have to work a little
at getting a full spec sheet from them.
 
R

Raveninghorde

Jan 1, 1970
0
"Raveninghorde"



** Why don't lying, know nothing,
SNIP


Eh ??



.. Phil

Public info here:

http://www.dstan.mod.uk/data/61/021/00000119.pdf

Section 25. 50 charge/discharge cycles. Test at -31C.

Section 17.4 states charger at 20C, battery at test temperature, max
charge time 5 hours.

That's a battery for a 1980's radio.

The batteries are available on Ebay if you want to see how they are
made.
 
P

PeterD

Jan 1, 1970
0
"Raveninghorde"


** Seems to me that even a well performing PSU might be damaged by
attempting to use it when its temp is -55C.

Better fit something that DISABLES the unit whenever the internal temp is
to low for safe operation - like a normally open bi-metal switch that
closes at 0C.



.... Phil

Or build in a small heater to keep the internal temperature above the
'magic' number! Lucky for you, in Oz, it never gets that cold! <g>
 
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