Maker Pro
Maker Pro

Need the topology for a current to current SMPS, not voltage tovoltage SMPS

J

John S

I CAN short circuit the current source, but I CANNOT afford to shunt off
POWER. As in, 'unused' power removed to somewhere else.

Okay, gotcha. Well, at 100% duty cycle, your minimum output power would
be about .05*5 or about 250mW with a 100R load. Will your load
resistance never get higher than that?
 
R

RobertMacy

Okay, gotcha. Well, at 100% duty cycle, your minimum output power would
be about .05*5 or about 250mW with a 100R load. Will your load
resistance never get higher than that?

changed the circuitry so the the current supply is around 0.335 and the
compliance is around 1kV, so a dead short still stops most of the power.

It's just I'm used to 'opening' a circuit to stop power, but opening the
circuit takes everything through horrific power levels on the way to
'OFF', other parts get the brunt. so a short should work - especially a
switch to gnd with less than 1 ohm impedance.
 
J

Joerg

RobertMacy said:
changed the circuitry so the the current supply is around 0.335 and the
compliance is around 1kV, so a dead short still stops most of the power.

It's just I'm used to 'opening' a circuit to stop power, but opening the
circuit takes everything through horrific power levels on the way to
'OFF', other parts get the brunt. so a short should work - especially a
switch to gnd with less than 1 ohm impedance.


How horrific depends on the time it takes to full open. Burning off 335W
for a few microseconds isn't such a big deal.
 
[email protected] wrote:
[email protected] wrote:
[...]

There are automotive electronics that work quite well, mostly in
Japanese cars. In the end it boils down to the reliability ratings of
the various entities in the know.
Things change. A lot!

That's what Maxim kept telling people :)

Touché. The difference is Maxim keeps proving that while things
change, management doesn't.


There was another guy who promised change. Actually hope and change. I
never saw the hope part and he made a royal mess.

Sign up for Obamacare yet? ;-)
However, I've been involved in many different markets at many
different levels, over the years. It's a *big* field. There is no
reason to do the same thing for forty years. Impossible, actually.

Not impossible. I met people who worked in one particular field such as
engine control units for over 30 years. I'd have a hard time doing that,
after being a consultant for this long.
ECUs have changed more than a little in 30 years. They will change
drastically, again, over the next ten. ...
Sure, incremental change. Same in medical ultrasound which is my home
turf. But ... after we built a flagship product in the late 80's and the
satellite R&D location was closed afterwards I wasn't too unhappy that I
could jump into consulting for the first time, and do something else.


... Hell, you'd have a hard time
showing up for work with your pants on, after being a consultant that
long. ;-)
As a consultant I get to wear shorts all summer long. When a web
conference with bigshots is coming up I have a "dress shirt on duty"
hanging in the lab closet :)
In my last job I was the only one who wore long pants from April to
October. Everyone else in Engineering wore T-shirts year 'round. I
can't do that. I wear long-sleeved shirts (Oxfords, preferred) even
for mowing the lawn.

I am just the opposite. I wear shorts and T-shirts as long as I can.
Only in really cold weather it's lumberjack shirts and jeans. For a
winter coat or jacket it almost would have to drop to below 0F.

Sure, I wear shorts[*] around the house, with Oxfords. I just can't
stand wearing T-shirts or even short-sleeved shirts. Spent a week at
the beach in September in swim trunks and oxford shirt. ;-)


Yikes. That is something I find odd. However, in places like Singapore
people even wear shorts with dress shirts and ties. But short sleeves.

I didn't get burned. ;-)

Haven't owned a short-sleeved shirt in at least 45 years (maybe in
high school - before I bought my own clothes).

I rarely deal with either buttons or shoe laces. Both are archaic wastes of
time.

Don't like pull over clothes of any kind. I have a few pullover
sweaters and sweatshirts but I rarely wear them. I really only need
something covering my shoulders and arms. Cardigans work, but aren't
currently in style so they're impossible to find.

Without laces, my shoes would fall off. Shoes without laces wouldn't
go on.
 
R

RobertMacy

How horrific depends on the time it takes to full open. Burning off 335W
for a few microseconds isn't such a big deal.

but when left OPEN there are components that still get huge amounts of
wattage AND high voltage! So, getting to OPEN fast just means the full
brunt is applied sooner not that you pass through a 'danger' zone and then
you are ok as it goes totally open. OPEN is the ABSOLUTELY worst case
condition for all those parts.

The lowest losses and lowest voltages on the components occur when trying
to drive a dead short. mV and mW
 
On Mon, 21 Oct 2013 19:59:06 -0400, [email protected] wrote:

[email protected] wrote:
[email protected] wrote:
[...]

There are automotive electronics that work quite well, mostly in
Japanese cars. In the end it boils down to the reliability ratings of
the various entities in the know.
Things change. A lot!

That's what Maxim kept telling people :)

Touché. The difference is Maxim keeps proving that while things
change, management doesn't.


There was another guy who promised change. Actually hope and change. I
never saw the hope part and he made a royal mess.

Sign up for Obamacare yet? ;-)

However, I've been involved in many different markets at many
different levels, over the years. It's a *big* field. There is no
reason to do the same thing for forty years. Impossible, actually.

Not impossible. I met people who worked in one particular field such as
engine control units for over 30 years. I'd have a hard time doing that,
after being a consultant for this long.
ECUs have changed more than a little in 30 years. They will change
drastically, again, over the next ten. ...
Sure, incremental change. Same in medical ultrasound which is my home
turf. But ... after we built a flagship product in the late 80's and the
satellite R&D location was closed afterwards I wasn't too unhappy that I
could jump into consulting for the first time, and do something else.


... Hell, you'd have a hard time
showing up for work with your pants on, after being a consultant that
long. ;-)
As a consultant I get to wear shorts all summer long. When a web
conference with bigshots is coming up I have a "dress shirt on duty"
hanging in the lab closet :)
In my last job I was the only one who wore long pants from April to
October. Everyone else in Engineering wore T-shirts year 'round. I
can't do that. I wear long-sleeved shirts (Oxfords, preferred) even
for mowing the lawn.

I am just the opposite. I wear shorts and T-shirts as long as I can.
Only in really cold weather it's lumberjack shirts and jeans. For a
winter coat or jacket it almost would have to drop to below 0F.

Sure, I wear shorts[*] around the house, with Oxfords. I just can't
stand wearing T-shirts or even short-sleeved shirts. Spent a week at
the beach in September in swim trunks and oxford shirt. ;-)


Yikes. That is something I find odd. However, in places like Singapore
people even wear shorts with dress shirts and ties. But short sleeves.

I didn't get burned. ;-)

Haven't owned a short-sleeved shirt in at least 45 years (maybe in
high school - before I bought my own clothes).

I rarely deal with either buttons or shoe laces. Both are archaic wastes of
time.

Don't like pull over clothes of any kind. I have a few pullover
sweaters and sweatshirts but I rarely wear them. I really only need
something covering my shoulders and arms. Cardigans work, but aren't
currently in style so they're impossible to find.

Me opposite. T-shirts and sweat shirts.
Without laces, my shoes would fall off. Shoes without laces wouldn't
go on.

People like Adidas used to make good velcro shoes, but they don't any
more. So I buy running shoes and replace the laces with Yankz elastic
laces, to convert them to slip-ons. Added advantage is that they don't
come untied.

Those are neat. I'll have to try a set or two.
 
J

Joerg

RobertMacy said:
but when left OPEN there are components that still get huge amounts of
wattage AND high voltage! So, getting to OPEN fast just means the full
brunt is applied sooner not that you pass through a 'danger' zone and
then you are ok as it goes totally open. OPEN is the ABSOLUTELY worst
case condition for all those parts.

The lowest losses and lowest voltages on the components occur when
trying to drive a dead short. mV and mW


Yeah, if it still wants to dump current at 1kV "open" isn't going to
work. I thought the thing was allowed to turn off in that case.

Without knowing what exactly you are doing all we can do it take
potshots at the problem.
 
P

Phil Hobbs

Easier to move, than clean? ;-)
Something like that. Mostly it's just always being in the middle of
several things at once.

Cheers

Phil Hobbs

--
Dr Philip C D Hobbs
Principal Consultant
ElectroOptical Innovations LLC
Optics, Electro-optics, Photonics, Analog Electronics

160 North State Road #203
Briarcliff Manor NY 10510

hobbs at electrooptical dot net
http://electrooptical.net
 
G

George Herold

Speaking of bizarre anachronisms, we recently watched the new
"Much Ado About Nothing", in modern dress but original Shakespearian dialogue,
filmed in b+w in a suburban LA house. Lots of cell phones and neckties.
Disconcerting but good.
A Joss Whedon production I think, my wife and daughter love Joss Whedon.

George H.
 
J

josephkk

John said:
On 10/19/2013 6:36 PM, Joerg wrote:
[...]


I'd like to get into beer brewing some day. When I did that last time as
a student in Germany I almost had more fun that when designing
electronics (which I did a lot while studying for my masters). Nowadays,
after designing the umpteenth switch mode converter that can get a bit
old. It's only fun if there is something in the mix where people have
said "it can't be done". That's when my fun level meter goes to 120%.


I dunno, Joerg. Isn't brewing sort of like watching paint dry? My desire
is that you poke something and can get an almost immediate response. I
obviously don't have your patience. Which is also my shortcoming.


For brewing one must have patience. Occasionally stuff has to just sit
there for a couple of weeks, your gear must be squeaky clean and
sterilized, you can't cut corners. Else you might ruin a day's worth of
work in minutes. When we brewed beer back in my university days we were
rather busy for a whole day and then again when it was time to bottle.
But we made sure there was a crate left over from last time and that
none of us had to drive that evening.

Yeah, I know. But, I can't sit still for a day let alone a couple of
weeks. I would die from boredom. I'm just not up to it. Others see it as
a challenge. It is why we are so diverse. Thanks, Momma (Nature), for that.

When i run a batch, it is almost like a couple of holidays a few weeks
apart. That is the main reason it is a hobby. Whip up the brew, go back
to electronics and whatever else for a couple of weeks, bottle it up or
set it up on tap or most likely both. The bottles are for friends that
can't just come over any time. I do require that the bottles be returned
to use again.

?-)
 
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