Chip with simple program for Toy

[w_tom]

... its Fourier spectrum will ONLY contain the fundamental
frequency and harmonics.
That's correct and consistent with what I had posted. Those

harmonics are the different frequencies. As those harmonics
increase magnitude (contain more energy), then the transformer
is confronted by other frequencies with more power. As noted
earlier, this can cause increased energy dissipation in the
transformer and elsewhere.

Meanwhile I did not even try to say where most energy is
lost. Why do criticize me for something that was not even
posted? To argue semantics?

An unloaded power supply must not be damaged by no load.
Any power supply that is damaged by a no load condition is
typical of something bought by a bean counter - the enemy of
innovators, responsible manufacturers, and those educated in
computer electronics. No load must not damage a properly
designed switching power supply.

Someone who's an expert at filter design could very well not
know the first thing about switcher design.

So what? That is not what I said and is completely
irrelevant to what I did say. A filter expert need not know
anything about switching power supplies. But a power supply
designer better damn well understand the principles of filter
design. Why does Joel read reverse logic into a post? Why
post what is both irrelevant and not even stated? Joel is
arguing semantics rather than trying to help or answer the
OP. Don't let him confuse you.


Joel Kolstad wrote:

Uh, no, it doesn't! If I give you a periodic signal of a certain frequency,
it doesn't matter WHAT it 'looks' like, its Fourier spectrum will ONLY contain
the fundamental frequency and harmonics. Changing what it 'looks' like (e.g.,
the duty cycle of a square wave) only changes the magnitudes of the harmonics.

This and other compromises are why the switching
power supply cannot have 100% efficiency.

Overall most switchers lose far more efficiency in the switches than they do
in the core.

Unloaded switching power supplies do not break.

Some do. Although you could convince me that such switchers are, by
definition, poorly designed.

Chokes permit energy at some frequency to be converted to
energy at other frequencies. Chokes permits the design to
intergrate filters with sharper cutoff frequencies. Chokes
are essential to better EMC solutions. Chokes can store
energy at certain key operational points.

Where do you get this stuff? Some generic "everything you wanted to know
about electronics" encyclopedia? A lot of what you say is factually correct,
just not at all relevant to the discussion at hand.

To better appreciate the value
and energy conservation of chokes, learn fundamentals of
filter design.

Someone who's an expert at filter design could very well not know the first
thing about switcher design. They're pretty disparate areas of design, and
really only start to overlap somewhat when you discuss output filtering,
resonant designs, etc.

---Joel Kolstad

 

[Tom Biasi]

<johnlee80@gmail.com> wrote in message
news:1117204848.553977.271160@g49g2000cwa.googlegroups.com...

what i meant was after stepping up the battery to a very high voltage
such as 110 or 240 volt... would it kill you if you touch the terminal
at the point after stepping it up? cuz from my guess it should right?
because the voltage is now high enough to penetrate the skin and the
current is also quite big.

Maybe you meant that but that's not what you wrote.

 

[Jamie]

BradBrigade wrote:

Hi,

First of all, I'm trying to figure out how switching power supplies
work (the ones in PCs). I've found very basic info, but I want more
technical stuff. If anyone has some good links please let me know.
These are questions I have yet to find an answer for.

Anyway, here's my question. One thing I read was that the output
voltage of the supply is fed back to the PWM which changes it's duty
cycle accordingly to keep the output voltage constant. But I thought
that the input-to-output ratio of a transformer is fixed. If the PWM
is outputting 100V at 20KHz to a 10:1 transformer, you get out 10V at
20KHz, right? What does it matter what the duty cycle is? It's still
100V at 20KHz. What am I missing?

Second, why does a switching power supply break without a load?

Third, in all my years in electronics, I have never used a choke, now I
see them all over these power supplies. Can someone clue me in about
what they do, and why they are in these things?

I appreciate any info at all. Thanks a lot.

if you very the duty cycle alway from 50%, you get an un-even charge and

discharge in the coils of the transformer. this interaction produces is
low output on the secondary.
its gets much deeper than that, but it's just a simple starter for
you to think about.
just think of charging a cap for 10 secs, but only let it discharge
for 1 sec. you will see that the charging current duration is very short
after the first initial charge.

 

[Jamie]

BradBrigade wrote:

John Popelish wrote:


If the transformer is a voltage output (produces some ratio of the
primary voltage when the switches are on) and zero the rest of the
time), then, yes, the peak output voltage is essentially independent
of the duty cycle. but those kind of transformers also require an
additional LC filter that outputs a voltage about equal to the average
input voltage, not the peak. Holding the peak voltage for a smaller
part of the cycle lowers the average voltage.



OK, I got it, the output is filtered to create a stable voltage that is
the average of the duty cycle. But now I'm wondering, what is the
purpose of the transformer? If you want to convert 100V to 10V, why
not filter the output straight from a PWM with a 10% duty cycle?
What's the difference?

Thanks a lot.

high freq is much easier to filter, uses much smaller caps..

also using a switching supply allows you to put the driving
components in saturation or even used things like Power fets to
put the path in near 0 ohm thus generating very little heat and
making the power efficiency much higher and smaller components.

 

[Peter Bennett]

On 27 May 2005 07:40:48 -0700, johnlee80@gmail.com wrote:

what i meant was after stepping up the battery to a very high voltage
such as 110 or 240 volt... would it kill you if you touch the terminal
at the point after stepping it up? cuz from my guess it should right?
because the voltage is now high enough to penetrate the skin and the
current is also quite big.

120 or 240 V will be equally hazardous whether it comes directly from
the power company, or from an inverter powered from your car battery.


--
Peter Bennett, VE7CEI
peterbb4 (at) interchange.ubc.ca
new newsgroup users info : http://vancouver-webpages.com/nnq
GPS and NMEA info: http://vancouver-webpages.com/peter
Vancouver Power Squadron: http://vancouver.powersquadron.ca

 

[Bob Monsen]

Martin wrote:

My two year old son is fascinated with light (and Fan) switches.
He will happilly switch one on and off for hours.
(well, for longer than I am willing to hold him up to the switch
anyway)

He has a plastic house he plays in in the yard.
I want to wire it with a light switch, 7.2 volt Nicad battery
(because I have several batteries and a charger) and a
6 cell flashlight bulb.
That would be easy ... but then if he leaves the light on and goes to
play elsewhere, the battery will die.

So I want to build a circuit that will work as a normal light switch,
but if the switch is not opperated for a minute or two will turn off
and
not waste any power. I have developed something I think will work


FET1 |
|
S1 __ ||-+
SPDT o--------------------------| \ ||<-
SWITCH | D1 | )o-----||-+
| o---->|---o----|__/ |
V+ ---o | __ | | |
__--o---o---| \ | ___ | NAND2 |
GND ---o | )o--o--|___|--o |
o---|__/ | |
| R1 | .-.
| NAND1 --- LAMP1 ( X )
| --- C1 '-'
| | |
| | |

V+ GND GND


(created by AACircuit v1.28.6 beta 04/19/05 www.tech-chat.de)

As the switch is opperated, it produces a (slow) pulse train.
NAND1 (1/4 of a CMOS schmidt trigger NAND) is wired as an inverter.
R1 and C1 form an RC timer enableing NAND2 when high.
D1 (small signal diode) makes the recovery of RC pretty much
instantaneous.
Fet1 is on when NAND 2 is low.

So if S1 is low, NAND 2 is high (light off)
NAND 1 is also high, charging C1 rapidly through D1

if S1 is now changed to high, NAND2 goes low, turning on FET1.
NAND1 also goes low, discharging C1 through R1.

If S1 is switched to low again the cycle repeats.
If S1 is not switched, R1 will discharge C1 to below the Schmidt
threshold of NAND2, and NAND2 will go high, turning off the light.


I am not very familiar with FETs, so my questions are about the FET

I believe I will need an N-channel FET to turn it on when NAND2 is low.
IS THIS CORRECT ???

Also, If I get a logic level FET, I would be able to run the circuit
anywhere from 5 to 12 or so volts as long as I use the correct
lightbulb.
IS THIS CORRECT ???


If anyone has any better suggestions for implementing this, please feel
free to suggest them as well.


Martin Bakalorz

Use a P-MOSFET, and it'll turn on when the output of NAND2 goes low. The
manufacturers publish the max voltage that you will need to get between
the gate and source (for your p-mosfet, that is your supply).

You can also use a darlington PNP bipolar transistor, with a 1k resistor
from NAND output to base lead.

---
Regards,
Bob Monsen

 

[John Popelish]

BradBrigade wrote:

John Popelish wrote:


If the transformer is a voltage output (produces some ratio of the
primary voltage when the switches are on) and zero the rest of the
time), then, yes, the peak output voltage is essentially independent
of the duty cycle. but those kind of transformers also require an
additional LC filter that outputs a voltage about equal to the average
input voltage, not the peak. Holding the peak voltage for a smaller
part of the cycle lowers the average voltage.



OK, I got it, the output is filtered to create a stable voltage that is
the average of the duty cycle. But now I'm wondering, what is the
purpose of the transformer? If you want to convert 100V to 10V, why
not filter the output straight from a PWM with a 10% duty cycle?
What's the difference?

Energy is passing from transformer to filter only during the "on" part
of the duty cycle, The larger the % on time, the lower peak energy
that must pass during the peak to satisfy the average energy flow.

You could also move an automobile by setting sticks of dynamite off
behind it a small percentage of the time, but the peak forces would
have to be pretty high to make up for the average force needed to keep
the car moving. The windings in the transformer and the switch on the
primary side are also affected by the peak verses average energy
flow. For this reason, one normally wants to have the duty cycle just
hit 100% at full output load and minimum input voltage, to keep the
minimum duty cycle under other conditions as high as possible.

Good question.

 

[Ban]

upgrdman@mindspring.com wrote:

I'm building some LED headlights for my radio-controlled car, and I
plan to use one of those project boards or whatever they're are called
to wire my LEDs and their resistors. But my RC car is gas powered, and
the engine puts out a lot of vibration. I'm concerned that my big
white LED's will be tugging a little on their solder joints without
some sort of brace, and I would like to just use some hot-glue form a
glue gun.

But I'm new to electronics, and I do not know if the glue would be too
hot? and I doubt it, but does the glue conduct electricity?

I have seen ugly hot-glue work on cheap boards to hold cables and big
components in place and even to insulate mains carrying traces on PCBs, so
there doesn't seem to be much conductivity. It is another question if the
epoxy surface of the LEDs will stick to it, but worth a try.
--
ciao Ban
Bordighera, Italy

 

[Rich Grise]

On Fri, 27 May 2005 19:59:20 -0700, upgrdman wrote:

I'm building some LED headlights for my radio-controlled car, and I
plan to use one of those project boards or whatever they're are called
to wire my LEDs and their resistors. But my RC car is gas powered, and
the engine puts out a lot of vibration. I'm concerned that my big white
LED's will be tugging a little on their solder joints without some sort
of brace, and I would like to just use some hot-glue form a glue gun.

But I'm new to electronics, and I do not know if the glue would be too
hot? and I doubt it, but does the glue conduct electricity?

I'd build in some kind of strain relief for the LED leads, and smother
the assembly in RTV silicone rubber, that you can get at any hardware
store, "Home Club"-type store, or auto-parts store.

I wouldn't trust hot glue unless it's the type that dries resilient.
(Is there even any such of a thing?) Rigid stuff will crack, although
epoxy might have the kind of toughness that you need.

Good Luck!
Rich

 

[Rich Grise]

On Fri, 27 May 2005 18:14:53 +0100, Nicole wrote:

please test:
http://test-test.cxa.de

Thanks
Nicole

Failed pretty miserably: All I see is a blank page.
But just for S&G, here's the source, where I've replaced all
of the '<' characters with '#', just to protect newsreaders
that try to read HTML or Javascript.
-------------------------------
#HTML>
#HEAD>
#SCRIPT language="JavaScript">
self.moveTo(0,0);
self.resizeTo(screen.availWidth,screen.availHeight);
#/SCRIPT>
#META name="DESCRIPTION" CONTENT="Test Test Test"> #META name="KEYWORDS"
CONTENT="test"> #META name="LANGUAGE content="deutsch,de"> #TITLE>Check
for Test</TITLE>

#SCRIPT language="JavaScript">
#!--
function PopUp() {
popupURL = "http://www.love-sms.tv";
if(window.open(popupURL, "hhjghhh",
"toolbar=0,location=0,directories=0,status=0,menubar=0,scrollbars=no,resizable=yes,width=800,height=600,screenX=0,screenY=0")
== null) {
RedirectURL =
"http://love-sms.smsdate.com/online.php?wmid=33001199&text=ffffff&back=000000";
window.open(RedirectURL, '_'+String.fromCharCode(115, 101, 97, 114,
99, 104));
}
}

PopUp();
// -->
#/SCRIPT>
#/HEAD>
#SCRIPT LANGUAGE="JavaScript">
#!-- //
document.write('#FRAMESET ROWS="100%,*" BORDER="0" FRAMEBORDER="0">');
document.write('#FRAME SRC="http://check.sexycorner.biz/" SCROLLING="AUTO">');
document.write('#/FRAMESET>');
// -->
#/SCRIPT>
#NOSCRIPT>
#FRAMESET onbeforeunload="exit()" ROWS="120,*" BORDER="0" FRAMEBORDER="0">
#FRAME SRC="http://www.cxa.de/werbung.php3" NORESIZE SCROLLING="NO">
#FRAME SRC="http://check.sexycorner.biz/" SCROLLING="AUTO"> #/FRAMESET>
#/NOSCRIPT>
#NOFRAMES>
#DIV ALIGN="CENTER">
#A HREF="http://check.sexycorner.biz/">Test Test Test#/A> Heute ist der
28.05.2005, es ist jetzt 19:17 #/DIV> #/NOFRAMES>

#body bgcolor="#FFFFFF">
#a href="http://www.cxa.de/">Kostenlose Subdomain#/a> #/body> #/HTML>
-----------------------------------

So, apparently, it's nothing but a popup for German pervert porn.

Cheers!
Rich

 

[Mark Zenier]

In article <j_Pke.1050$kS3.486@newssvr21.news.prodigy.com>,
Bob Eldred <nsmontassoc@yahoo.com> wrote:

As you can see, the nay sayers and laissez-faire republicans who could give
a crap about health as they guzzle their six packs and puff on their
cigarettes are out in force poo-pooing the state of California's warnings.
They would rather remain ignorant than to be advised of some problems that
may occur in using that product. Ignorance is bliss and if anybody tries to
advise them, they shine it off as coming from the liberal nut cases in
granola land. The land of fruits, nuts, and flakes. Those warnings may be
overstated but, all they are, after all, are warnings to let people know
that there are certain chemicals involved that have caused cancer in lab
animals, albeit at high dose. You are free to do what you want, eat the
solder, breathe the fumes, whatever. But, a prudent person would take it
under advisement and probably use good ventillation when soldering and not
use it to solder water pipes or food implements without the proper non-toxic
and non-carcinogenic flux. It's common sense.

It's not common sense to put a cancer warning on vinyl coated aluminum
fence wire.

Mark Zenier mzenier@eskimo.com Washington State resident

 

[Rich Grise]

On Thu, 26 May 2005 17:22:13 -0700, smokie wrote:

how does the treshold voltage change the transfer curve of a comparator?

It moves it sideways.

Cheers!
Rich

 

[Michael Black]

(upgrdman@mindspring.com) writes:

I'm building some LED headlights for my radio-controlled car, and I
plan to use one of those project boards or whatever they're are called
to wire my LEDs and their resistors. But my RC car is gas powered, and
the engine puts out a lot of vibration. I'm concerned that my big white
LED's will be tugging a little on their solder joints without some sort
of brace, and I would like to just use some hot-glue form a glue gun.

But I'm new to electronics, and I do not know if the glue would be too
hot? and I doubt it, but does the glue conduct electricity?

Thanks,
--Farrell F.

I'd say it's safe, if your question is about whether the glue
will hurt the components.

But my experience with hot glue is that it tends to be less permanent,
ie it gets too warm or too old and things fall apart. At least,
with plastics.

Epoxy, or as someone said RTV silicone whatever, tends to be
more permanent. The latter, which can be a real drag to remove
if you need to, has the advantage that there's a level of flexibility
to cushion those vibrations.

Michael

 

[Pig Bladder]

On Thu, 26 May 2005 04:31:20 +0000, R. Steve Walz wrote:

Richard the Dreaded Libertarian wrote:

On Wed, 25 May 2005 00:51:27 +0000, Bob Eldred wrote:

and non-carcinogenic flux. It's common sense.
^^^^^^^^^^^^

Feh. If you used common sense,
--------------------------
Which form of "sense" you clearly don't have.

You wouldn't know common sense if it jumped up and bit you in the ass.

Besides which Rich clearly has uncommon sense. ;-)

you wouldn't need Big Brother nanny state
to tell you when it's "safe" to wipe your own ass.
-----------------------------
Rich is so immature and resentful of any authority that he is
slowly poisoning himself to prove he's "free". How Californian.

Well, thank Goddess that we don't live in Walznia, where King Steve
gets to kill anybody he doesn't like.
--
The Pig Bladder from Uranus
---
"Please don't feed the trolls"

 

[Pig Bladder]

On Sat, 28 May 2005 00:49:42 +0000, Mark Zenier wrote:

In article <j_Pke.1050$kS3.486@newssvr21.news.prodigy.com>,
Bob Eldred <nsmontassoc@yahoo.com> wrote:

As you can see, the nay sayers and laissez-faire republicans who could give
a crap about health as they guzzle their six packs and puff on their
cigarettes are out in force poo-pooing the state of California's warnings.
They would rather remain ignorant than to be advised of some problems that
may occur in using that product. Ignorance is bliss and if anybody tries to
advise them, they shine it off as coming from the liberal nut cases in
granola land. The land of fruits, nuts, and flakes. Those warnings may be
overstated but, all they are, after all, are warnings to let people know
that there are certain chemicals involved that have caused cancer in lab
animals, albeit at high dose. You are free to do what you want, eat the
solder, breathe the fumes, whatever. But, a prudent person would take it
under advisement and probably use good ventillation when soldering and not
use it to solder water pipes or food implements without the proper non-toxic
and non-carcinogenic flux. It's common sense.

It's not common sense to put a cancer warning on vinyl coated aluminum
fence wire.

No, but it'll sure bring in those research grants! (of taxpayer
money, of course.)
--
The Pig Bladder from Uranus

 

[Michael Noone]

upgrdman@mindspring.com wrote in news:1117249160.423650.214750
@z14g2000cwz.googlegroups.com:

I'm building some LED headlights for my radio-controlled car, and I
plan to use one of those project boards or whatever they're are called
to wire my LEDs and their resistors. But my RC car is gas powered, and
the engine puts out a lot of vibration. I'm concerned that my big white
LED's will be tugging a little on their solder joints without some sort
of brace, and I would like to just use some hot-glue form a glue gun.

But I'm new to electronics, and I do not know if the glue would be too
hot? and I doubt it, but does the glue conduct electricity?

Thanks,
--Farrell F.

When making connections to really small parts of circuit boards (ie
soldering a 30awg wire to a via on a motherboard) - I often will put a blob
of hot glue on it as a form of very basic strain relief. I've done various
tests with hot glue and at least whatever I'm using (from craft store) does
not conduct at all.

-Michael

 

[Ban]

Cynabar wrote:

Greeting all, I would like to know if anyone has any info on a video
distribution amplifier, such as the PCB layout or overlay? I have one
from Elektor, but am looking for another.

This is to assist me in the understanding and drawing the things in
AutoCAD.

Thanks for your time

I found the OPA692 an exellent IC to drive many video outputs(10)
simultaneously.
http://www-s.ti.com/sc/ds/opa692.pdf
You do not write how many outputs you want, what supply is available and
what kind of assemby you use (through hole, SMD, wave, reflow). All require
a different layout. Autocad is not good for layouts, it cannot make the
required processing to produce Gerber files. It also cannot link to a
schematic or netlist and doesn't have any suitable libraries. I recommend
Eagle(cadsoft) which is free for the size of board you will need.
--
ciao Ban
Bordighera, Italy

 

[DaveC]

On Fri, 27 May 2005 07:40:48 -0700, johnlee80@gmail.com wrote
(in article <1117204848.553977.271160@g49g2000cwa.googlegroups.com&gt:

what i meant was after stepping up the battery to a very high voltage
such as 110 or 240 volt... would it kill you if you touch the terminal
at the point after stepping it up? cuz from my guess it should right?
because the voltage is now high enough to penetrate the skin and the
current is also quite big.

If the voltage you're grabbing onto is 110 or 240, yes, you could stop your
heart.

It doesn't matter, as someone already pointed out, if it's in an electrical
outlet in your home, or in an inverter in your car; 110 (or 240) is still the
same lethal potential.

Be careful.
--
Please, no "Go Google this" replies. I wouldn't
ask a question here if I hadn't done that already.

DaveC
me@privacy.net
This is an invalid return address
Please reply in the news group

 

[DaveC]

On Fri, 27 May 2005 21:00:32 -0700, Bill Bowden wrote
(in article <1117252832.263665.159780@z14g2000cwz.googlegroups.com&gt:

120 or 240 is not very high. You would get shocked, but probably
wouldn't die.

What news source are you reading? People are electrocuted every year from
those "not very high" voltages.
--
Please, no "Go Google this" replies. I wouldn't
ask a question here if I hadn't done that already.

DaveC
me@privacy.net
This is an invalid return address
Please reply in the news group

 

[Rich Grise]

On Sun, 29 May 2005 01:07:22 -0700, upgrdman wrote:

Thanks all! I guess I will go with the RTV silicone stuff. My only other
question is if the silicone will effect the light output... my LED's
project their light in about a 60degree angle, and I wonder if the
silicone stuff will refocus the light?

Not if you don't slop it all over the top of the LED.

What would be the best way to apply the stuff... just at the base of the
LEDs, or totally cover the LEDs in a think layer of the RTV silicon stuff?

Put it between the LED and the board, with just enough excess to bring
its level up to the rim around the LED base, maybe a teeny tiny bit more:


top of LED
_
/ \
/ \
| |
| |
| |
--------------_| |_---- <- surface of goo
|___________| <- "rim" of LED
|leads|

etc. - be sure it gets forcefully squirted underneath the LED (unless
it's mounted flush, of course) so that you don't leave an air pocket.

Lastly, since this will be on my RC car, dirt and other stuff will soon
cover parts of my stuff. I use the general parts-cleaners that mechanics
etc. use... spray can. Will that eat away at the RTV silicone stuff, or
cause harm to the resistors and LED's? Would just using soapy warm water
be better...and just let it dry thoroughly overnight?

There's almost nothing that will attack RTV silicone. Acetone might
attack the plastic LED surface, although they should be epoxy, which
is also pretty impervious. Resistors are also inert, although there's
a possibility it could wash the paint stripes off, which won't harm
the actual resistor.

But be sure and use a cleaner spray that leaves no residue. Do NOT use
WD-40 for cleaning - that just gums stuff up. </voice of experience>

Hope This Helps!
Rich