Driver to drive?

[Mark Zenier]

In article <a69e22f6.0411041954.28fc388e@posting.google.com>,
Yzordderex <yzordderrex@verizon.net> wrote:

What is a L200c?

It's like a LM317 with an adjustable current limit. 5 pin TO-200.
Only about 12 watt power dissipation. From ST.

Mark Zenier mzenier@eskimo.com Washington State resident

 

[Pooh Bear]

Kevin Aylward wrote:

Pooh Bear wrote:
Kevin Aylward wrote:

Well, I am currently playing around with simulations of an audio amp
using state of the art bipolar (ft=50Mhz, 15A, 230V, 150W) and its a
no contest. Mosfets switch much faster. I can get 1000V/us (500W
@8ohms) with mosfets, only about 100V/us with bipolar.

And such slew rates are relevant to audio in *which* way ?


One-upmanship/specmanship. Its the challange dude.

Why do people Climb Mt. Everest?

Oh - OK then !

Graham

 

[Rich The Philosophizer]

On Sun, 07 Nov 2004 03:51:12 +0000, Ratch wrote:

Nothing wrong with being a prude if that is what you want to be. You
would not want to live in the US because most folks here consider homos
to be abnormal. That is what US society decided. You can say they are
wrong, but they control what happens in this democracy. Homos do have a
uphill course if they want to attain high public office, but that's fine
with me. They not only have to convince the public that they acknowledge
their perversion, but their actions in dealing with it will not ruffle
the feathers of the majority.

Where did you get your obsession with other people's sex lives?

Thanks,
Rich

 

[Rich The Philosophizer]

On Sun, 07 Nov 2004 15:56:54 +0000, Kevin Aylward wrote:

Pooh Bear wrote:
Kevin Aylward wrote:

Well, I am currently playing around with simulations of an audio amp
using state of the art bipolar (ft=50Mhz, 15A, 230V, 150W) and its a
no contest. Mosfets switch much faster. I can get 1000V/us (500W
@8ohms) with mosfets, only about 100V/us with bipolar.

And such slew rates are relevant to audio in *which* way ?


One-upmanship/specmanship. Its the challange dude.

Why do people Climb Mt. Everest?

Because somebody told them to?

Or sombebody told them not to?

Thanks,
Rich

 

[Terry Given]

Radiohead wrote:

I've just started to learn about matrix converters as part of my
university course, and I've been asked to decide which is the best
device to use in a matrix converter out of MOSFET, IGBT, Thyristor.

It looks to me like MOSFETs & IGBTs are the best but I'm not sure which
is the right answer. I'm thinking it might depend on the voltage &
current, and so there is no answer that is correct for all cases. Is
this right?

If any one has any experience of this I would appreciate your coments.
Many thanks.

I have yet to see a real product made with matrix converters. Prior to
the late 1990s, nobody in their right mind use FETs above about 600V
because Rdson was proportional to BVdss^2.6. That all changed (thanx
infineon, IR) but even so, its hard to get a decent 1000V FET, and even
then they are puny. It is trivial to obtain a 1kA 3.3kV IGBT, (or 2kA
1.2kV) which is puny compared to the thyristors you can buy - 6kV, 9kA
in a hockey puck isnt exactly huge. You should see the stacks of these
things used in MV MVA (yes, megavolt, megawatt) inverters and
rectifiers. The great thing about thyristors is (if you control the
energy) they fail short-circuit (if you dont control the energy they can
and do vaporize). So big inverters have many thyristors in series
(literally stacked one atop another), with many more than are required
to meet the voltage spec. That way, multiple devices can fail and the
inverter still works, and can be repaired at a convenient time. in NZ we
have a DC link between the south (lots of hydro power here) and north
(lots of consumers) islands; if the inverter at haywards blows up, 2/3
of the population pretty much goes without electricity until it works
again (gross oversimplification)

Clearly power level is important - at 6W 300V it would not be clever to
use IGBTs, but then a matrix converter would be a pretty stupid idea
anyway. GTO thyristors allow you to turn the darned things off, unlike
SCRs.

Matrix converters have the disadvantage of no DC bus (its their
advantage too), making it much more difficult to prevent inductive
overshoot - which kills IGBTs very quickly. This generally requires a
lot of snubbing, increasing size, cost, power dissipation etc. And of
course the switches need to be bidirectional, so there are a LOT of them.

Cheers
Terry

 

[Mike Page]

Fred Bloggs wrote:

Frank Bemelman wrote:

That's why it such a tragedy to see that this piece of shit is
elected for the *second* time. All Bush voters are ignorant peasants.
Fucking ignorant peasants. No fucking brains at all. Fucking
puppets on strings.


I know more than a few people who are frustrated to the point of so much
anxiety, depression, and distraction over the election and four more
years of Bush that they need therapy. I have never in my life seen this
level of discontent over a Presidential election. There is a very
serious and large scale problem here.

You really should get out more.

 

[Terry Given]

Ratch wrote:

"Fred Bloggs" <nospam@nospam.com> wrote in message
news:418B9DF8.5080006@nospam.com...


John Fields wrote:

On Fri, 05 Nov 2004 03:08:51 GMT, "Ratch" <Watchit@Comcast.net> wrote:



"John Larkin" <jjlarkin@highSNIPlandTHIStechPLEASEnology.com> wrote in
message news:udklo0h3gh5f79bsjvfusanuphhej3cqec@4ax.com...
On Thu, 04 Nov 2004 21:59:51 GMT, "Ratch" <Watchit@Comcast.net> wrote:


You behave the way you're wired, and so do they; it's only a toss of the
chromosomes that made you straight.

No one knows for sure if chromosomes are the reason or not. That's
immaterial. The point is that some people are not normal, but they have

a

obligation to society not to misbehave by exhibiting certain specific
abnormalities.


---
Like being Black?


Don't waste your time on him- this Ratch maggot traces to Minnesota- he
lies about seeing anyone walking around nude, men kissing in public, or
men holding hands.


This is a small world. While the above scenes are not predominate like
in Crisco, they do happen sometimes. Anyway the mass media keep us informed
about what happens elsewhere. And what goes no there will sooner or later
come here.

you seriously believe the shit that spews out your TV set? turn it off,
you'll feel yourself growing smarter by the minute. "mass" media is
precisely that - media for the masses. A quick look at a normal
distribution should be enough to show that half of all americans are at
or below average intelligence (which aint that high - an IQ of what,
105?). Mass media targets these people, with stupid stories about cats
and very small words. Nice, easy-to-recall soundbites, more like jingles
than than news.

He is a brainwashed moron suckered into joining the
religious right on this issue- Jerry Falwell routinely sends undercover
cameras into gay events and rallies to capture all this stuff on video
and then sells the garbage to his followers.


All vituperative speculation and untrue.

10 points for being the first person other than myself to use
"vituperative" in a post.

Ratch is the kind of moron
who gave us four more years- happy now?


Yes, it turned better that I hoped. Relatively little election conflict
and a gracious concession from the loser. Ratch

Nobody can blame the legal profession for this - its officially
self-inflicted.

Cheers
Terry

 

[Rich The Philosophizer]

On Sun, 07 Nov 2004 15:36:49 -0700, Mark Fergerson wrote:

Rich The Philosophizer wrote:

We hold these truths to be self-evident, that all men are created equal,
that they are endowed by their Creator with certain unalienable Rights,
that among these are Life, Liberty and the pursuit of Happiness. --That to
secure these rights, Governments are instituted among Men, deriving their
just powers from the consent of the governed, --That whenever any Form of
Government becomes destructive of these ends, it is the Right of the
People to alter or to abolish it, and to institute new Government, laying
its foundation on such principles and organizing its powers in such form,
as to them shall seem most likely to effect their Safety and Happiness.
Prudence, indeed, will dictate that Governments long established should
not be changed for light and transient causes; and accordingly all
experience hath shewn, that mankind are more disposed to suffer, while
evils are sufferable, than to right themselves by abolishing the forms to
which they are accustomed. But when a long train of abuses and
usurpations, pursuing invariably the same Object evinces a design to
reduce them under absolute Despotism, it is their right, it is their duty,
to throw off such Government, and to provide new Guards for their future
security.

- Excerpt from The Declaration Of Independence

So, you see? It's our _duty_ to overthrow the Cheney/Rumsfeld cartel and
their dummy, whom I'm understandably reluctant to say the name of in
such a "subversive" and yea verily "treasonous" post as this.

I used to think you could read. Note that it says "any
Form of Government", not "any particular seat-occupiers".

Well, speaking of comprehension, when the Form approaches the form

of a fascist regime, the people are supposed to prevent that, and
restore the form of their government to that of a democracy.

Better?

Thanks,
Rich

 

[john jardine]

"Pooh Bear" <rabbitsfriendsandrelations@hotmail.com> wrote in message
news:418DFDBE.D2AE46CE@hotmail.com...

john jardine wrote:

"Pooh Bear" <rabbitsfriendsandrelations@hotmail.com> wrote in message
news:418C837D.38906D0B@hotmail.com...
[clip]

Look at high power and there's hardly a pro-electron designation device to
be
seen. Mainly 'cos there aren't any of note. Indeed I'm barely aware of any
newish pro-electron designation types at all.

Many power devices of note are manufacturer part no type - like the MJs.
[]

Graham

Yes indeed. The pro-electron system is non existant once beyond the jelly

bean end of market.
It's historically yet another of those half arsed trade protection measures
that fell over at the first fence, leaving us stuck with it's flotsam.
(those damned IEC logic symbols and the German DIN standards also come to
mind)
regards
john

 

[Anders F]

"Mike Deblis" <mdeblis@hotmail.com> wrote in message
news:bc45f679.0411020757.58ab9f18@posting.google.com...

Hi,

I have a project that I want to have made commercially - maybe a
maximum of 1000 units, but only 50 to start with. I am not a
practicing engineer.

There are about 40 components - I want most to be SMD... no BGA, but a
few uSOP and mostly 0805 Rs & Cs (a couple of larger tant Cs). Some
non-standard, e.g. power connector & SMD inductor etc. I want SMD
because I want the unit to be compact... 2-layer PCB, 10mil traces,
FR4 with solder mask on both sides & silk screen one side (i.e. a very
standard board).

So, is PTH cheaper to make than SMD?

Probably not.

For a small board like this
(maybe 10cm x 10cm) what might I expect to pay for assembly?

Depends on volume and site!

Is it
worth going to the Far East for quotes

Not for 50pcs. If you do say +500: yes.

- what quality issues might
that entail? If there are one or two PTH devices on the board, does
this really complicate matters or is it incidental?

In Europe/US it will. More processes / work. In asia eastern europe it's
peanuts - don't worry!

I really would apprecate a few pointers about where to get started,
and experiences of using local vs. remote far East etc.)
fabricators...

Do a prototype "at home" to verify everything.

Check locally for small series. You'll get lots of problems
handling/communicating with far away people...

Cheers,
Anders

many thanks

Mike

 

[Rich Grise]

On Tue, 02 Nov 2004 13:15:21 +0000, Jim Yanik wrote:

"Kevin Aylward" <salesEXTRACT@anasoft.co.uk> wrote in
news:ADGhd.8285$Bk6.6374@fe2.news.blueyonder.co.uk:

John S. Dyson wrote:
In article <4186FAE0.3050604@nospam.com>,
Fred Bloggs <nospam@nospam.com> writes:


Tom Seim wrote:
There have been claims on SED that Kerry has never admitted to
committing atrocities in Vietnam. Well here is the transcript from
Kerry's appearance on "Meet the Press". You decide for yourself:

(Videotape, April 18, 1971):

MR. KERRY: There are all kinds of atrocities, and I would have to
say that, yes, yes, I committed the same kind of atrocities as
thousands of other soldiers have committed.

(End videotape)

You're are not very high up on the evolutionary ladder apparently.
What Kerry considered an atrocity after the war was considered
standard military action during the war.

John Kerry, being a commander, was obviously assisting in committing
and ordering atrocities. He admitted to complicity.

Whether or not anyone else is a combat veteran doesn't change the fact
that John Kerry has effectively claimed being a war criminal (his
words sanitized for legal reasons, obviously.) Voting for a war
criminal would be ethically and morally MUCH WORSE than voting for an
AWOL or draft dodger who went to Canada. The idea of someone who
knowingly PERSONALLY destroyed a familys means of earning a living,
or killing numerous family members because of (orders) being
president of the USA IN THESE MODERN TIMES is disgusting.

We don't need to let that war criminal, Kerry, become president.
Murdering for absolutely no reason, in the heat of war, and
destroying very poor peoples little huts is heinous. Kerry has
shown other abhorrent attitudes and behaviors.

John Kerry is obviously a bad, bad man. He might even be a very evil
man, but that isn't any persons' place to judge, but it appears to be
true.


I don't care, even if he was. Bush is worse. Bush is the most worthless
disgusting piece of shit to hold American office, in my view.

Kevin Aylward

So you hate Bush,and that clouds your judgement.

Well, we hate evil, and you love evil - whose judgement is "clouded"?

Thanks
Rich

 

[Pooh Bear]

Ken Smith wrote:

In article <0f0to0l5m6uc0s1e7214kccj4v79d1pd9b@4ax.com>,
Jim Thompson <thegreatone@example.com> wrote:
On Sun, 07 Nov 2004 20:15:12 GMT, Rich The Philosophizer
null@example.net> wrote:

On Sun, 07 Nov 2004 15:56:54 +0000, Kevin Aylward wrote:

Pooh Bear wrote:
Kevin Aylward wrote:

Well, I am currently playing around with simulations of an audio amp
using state of the art bipolar (ft=50Mhz, 15A, 230V, 150W) and its a
no contest. Mosfets switch much faster. I can get 1000V/us (500W
@8ohms) with mosfets, only about 100V/us with bipolar.

And such slew rates are relevant to audio in *which* way ?


One-upmanship/specmanship. Its the challange dude.

Why do people Climb Mt. Everest?

Because somebody told them to?
Or sombebody told them not to?

Thanks,
Rich

It only takes ~7V/uSec slew rate to reproduce 20KHz at 200W into 8
ohms.

So the only arguments for higher slew rate would be perhaps:

1) Scooting thru dead-band in the output... not necessary if you
actually know how to design an amplifier, instead of being a blowhard
;-)

2) Then there's the Class-D crowd :-(

3) The music is intended for dogs, cats or bats.

4) The design goal is for 10KW of audio

10 kW of 20 kHz ?

Sheesh ! Sadly can't hear that high any more. Maybe 10 kW would help ?


Graham ;-)

 

[Rich Grise]

On Mon, 08 Nov 2004 03:45:10 +0000, Ratch wrote:

"Rich The Philosophizer" <null@example.net> wrote in message
newsan.2004.11.07.19.17.16.689680@neodruid.org...
On Sun, 07 Nov 2004 03:51:12 +0000, Ratch wrote:

Nothing wrong with being a prude if that is what you want to be. You
would not want to live in the US because most folks here consider homos
to be abnormal. That is what US society decided. You can say they are
wrong, but they control what happens in this democracy. Homos do have a
uphill course if they want to attain high public office, but that's fine
with me. They not only have to convince the public that they acknowledge
their perversion, but their actions in dealing with it will not ruffle
the feathers of the majority.

Where did you get your obsession with other people's sex lives?

It's a concern, not an obsession. You should have asked, "Why are you
concerned with other peoples sex lives when they have strange proclivities,
and want the majority of society to approve their lifestyle and change laws
to coincide with their aberrant behavior?" Learn to ask the right
questions. Ratch


Thanks,
Rich

Ratch, print out this thread and take it to your physician.

Please.

Good Luck,
Rich

 

[Kevin Aylward]

Jim Thompson wrote:

On Sun, 07 Nov 2004 20:15:12 GMT, Rich The Philosophizer
null@example.net> wrote:

On Sun, 07 Nov 2004 15:56:54 +0000, Kevin Aylward wrote:

Pooh Bear wrote:
Kevin Aylward wrote:

Well, I am currently playing around with simulations of an audio
amp using state of the art bipolar (ft=50Mhz, 15A, 230V, 150W)
and its a no contest. Mosfets switch much faster. I can get
1000V/us (500W @8ohms) with mosfets, only about 100V/us with
bipolar.

And such slew rates are relevant to audio in *which* way ?


One-upmanship/specmanship. Its the challange dude.

Why do people Climb Mt. Everest?

Because somebody told them to?
Or sombebody told them not to?

Thanks,
Rich

It only takes ~7V/uSec slew rate to reproduce 20KHz at 200W into 8
ohms.

Ahh... but lets do some other numbers...

So the only arguments for higher slew rate would be perhaps:

Oh...

1) Scooting thru dead-band in the output... not necessary if you
actually know how to design an amplifier, instead of being a blowhard
;-)

You missed my comments on this then? You know, the bit about high slew
rate being a side effect?

Ok...

Consider an input differential pair. Using ***SUPERSPICE***, we can
compute the distortion as a function of offset. If the input stage is
supplying large currents to the miller cap for a HF signal, other
signals superimposed on this current will treat this current as an
unbalance/offset of the input pair. This results in the usally canceled
2nd harmonic to appear. What do the numbers say?

Well we get, with 10mv (optimistic at 20Khz, 50 volts out) in:

With 100ohm * 2 emitter resisters No emitter resister

Current per T 2nd Harmonic 2nd Harmonic

1.9ma/0.05ma -25db -20db
1.8ma/0.2ma -35db -22db
1.4ma/0.6ma -54db -29db
1.2ma/0.8ma -76db -35db
1.05/0.95ma -87 -47db
1ma/1ma -112db -90db

What do the numbers mean?

If we take the 1.9ma/0.05ma as the nominal slewing condition, the
distortion at that point is pretty horrendous. If we back of the slew to
almost half its maximum rating, 1.2ma/0.8ma, the no emitter resister
case still has quite a large distortion of -35db (1.7%). Of course
feedback will reduce this, but often there is not a lot of loop gain at
20K to do this. The emitter resister case gives a 40db improvement at
the *same* slew induced offset.

101 op-amp design tells us that to increase the slew rate, by say,
reducing the compensation capacitor requires the gm to be reduced in
order to get the same unity gain point, e.g. adding in emitter
resisters. The above numbers suggest that a slew rate of around twice
the large signal limit is a good starting point. Above that, the
distortion, *if* emitter resisters are used, falls off to
insignificance.

In this typical example, to keep the same loop gain, the slew rate with
no resisters would be around 100oms/25ohms = 4 times less. That is,
given an amp that was already stable and slewing at 20khz without
emitter resisters, adding the resisters to reduce HF distortion will
result in a slew of 80khz.

So, the side effect of achieving large slew rates by a usual addition of
gm reduction is to automatically minimise HF distortion or vice versa

Kevin Aylward
salesEXTRACT@anasoft.co.uk
http://www.anasoft.co.uk
SuperSpice, a very affordable Mixed-Mode
Windows Simulator with Schematic Capture,
Waveform Display, FFT's and Filter Design.

 

[Andrew Holme]

Terry Given <my_name@ieee.org> wrote

5V
+--+
| |
K__ )
/\ (
-- )
A | (
| | Relay
+--+

The problem is that if device (EM lock) is connected, MCU will hang
after 1 day. I am saying that it hang since PC connected to it using
serial port unable to receive or send signal.

If the device is not connected, it works fine. At this point (and in
mydesperation to explain this) I thought that somehow the relay 12V
output is giving interference to the MCU. Since the relay is normally
open, the 12V current is there almost all the time.

Two things:

Fistly, stick a "freewheeling" (catch) diode across the relay coil,
cathode to +5V - I have modified your diagram suitably. When you turn
the transistor off (P1.7 = 0) Lenz's law makes the collector voltage
shoot quite high - the catch diode clamps it to 5.7V, allowing the
energy stored in the relay coil to flow back into the +5V supply.
Without the catch diode, the transistor may well fail.

I second this.

Just one thing - the energy doesn't flow into the supply. The diode
short-circuits the back EMF. The energy is dissipated in the coil and
the diode.

Secondly, look at your "gnd" connection. I would twist gnd, P1.7 and +5V
together, and connect them all up at the micro (put the 10k there).

If the problem persists, and your load will tolerate it, you could
write a test program which rapidly toggles the output. If you can
reproduce the problem more frequently (<1 day) it may be easier to
investigate. You you can look on the MCU power supply with a 'scope
and see if you have any glitches.

 

[John S. Dyson]

In article <pan.2004.11.01.22.51.20.581959@example.net>,
Rich Grise <rich@example.net> writes:

On Mon, 01 Nov 2004 13:46:11 -0800, Winfield Hill wrote:

Tom Seim wrote...

Site now directed to Air America Radio.

No, it's redirected to http://www.amerika.com, which is
someplace else, with a set of anti-Bush links arranged
in a cricle about the amerika.com symbol, a big W with
a slash through it.

Air America Radio is simply the link that happens to be
on top of the circle of links.

Guess they didn't like the way the polls are going!

Who are the amerika.com folks anyway? And who was
www.realpolitics.com before they got hacked? Or are/
were they really the same as amerika.com all along?

Just from looking at a couple of links, it looks like sort of
a coalition of people who know that Bush must go.

The lefty/liars keep on forgetting that there is a right way

of doing things and the wrong way (that is, the unethical, illegal
and/or immoral way is apparently the leftist way -- given the
behavior of the American leftist.)

Remember, Kerry is a proven, dangerous liar. Did you see the
old interview of Kerry (on Sunday TV) where he admitted to
war crime type behavior (or lied about it -- pick which one?)

Yes. The proven fact is that Kerry is a liar, likely without

any consciousness (like alot of lefties.) Remember, for the left
it is almost always the ends justifies the means when they
are on their demonic crusades against freedom, religion
and other aspects of life that should allow some tolerance
for others. Truly, the American left is incredibly doctorinare
and has little toleration or respect for others. I do tolerate
most leftist ideals, where I can accept the influence of the left
with a live or let live attitude, except when their baby killing
advocacy espouses its secular (and probably moral) evil with their
advocacy for killing the 100% innocent human beings, very seldom
strongly advocating the life sparing alternatives. (Every dead
innocent American black, white, brown, baby is a success for
the American leftist baby killers!!!) They are truly non discriminatory
in their lack of respect for the lives of little, innocent babies.

John