Chip with simple program for Toy

[Wayne Farmer]

"paul" <reetix@gmail.com> wrote in message
news:1115246621.068110.165600@f14g2000cwb.googlegroups.com...

Hello,

Today I plugged in a power meter I bought a while ago, and decided to
check out how much power my old Pentium 233MMX was using, here are the
results (UK Power):

Normal Operation
244 Volts, 0.21 Amps, 31 Watts, Power Factor = 0.60

But if I disconnect the hard drive, I get:
250 Volts, 0.17 Amps, 41 Watts, Power Factor = 1.00

How could it be using more power when the hard drive is disconnected?
41 Watts is how much power it is using, right? Which one (if any) is
accurate?

Thanks!

paul

Based on my limited knowledge (having just finished an AC circuit theory
course at my local community college), I believe there are 3 ways to measure
the power drawn by a load from an alternating voltage source:

1. Apparent power. This is RMS AC Volts x RMS AC Amps. It is reported not
in Watts, but in "VA" = Volt-Amperes.

2. True power. This is the resistive component of Apparent Power, and is
reported in Watts. If the load has no capacitive or inductive elements,
then all the load is resistive. True power is the power that is dissipated
in heat through your load.

3. Reactive power. This is the inductive and capacitive (= reactive)
component of Apparent Power, and is reported in "VAR" = Volt-Amperes
Reactive. Reactive power isn't dissipated in heat, but cycles back and
forth between you and the power company as alternating current flow.

Apparent power is the vector sum of True Power and Reactive Power: the
square root of (True Power**2 + Reactive Power**2).

The ratio of True power to Apparent power is the Power Factor.

Motors (hard drives, fans, etc.) are typically inductive loads.

Now let's look at the figures your meter is reporting:

Normal Operation
244 Volts, 0.21 Amps, 31 Watts, Power Factor = 0.60

244 V x .21 A = 51.2 VA apparent power. Of that, the 0.60 Power Factor x
51.2 VA = the 31 Watts true power being consumed by the resistive loads in
your computer and hard drive. At the same time, there is a reactive
(inductive and capacitive) power draw of sin(arccos 0.60) x 51.2 VA = 41
VAR. The square root of (true power**2 + reactive power**2) is indeed 51.4
VA, which matches your figure of 51.4 VA.

But if I disconnect the hard drive, I get:
250 Volts, 0.17 Amps, 41 Watts, Power Factor = 1.00

250 V x .17 A = 42.5 VA apparent power. Since the Power Factor is 1.00, all
of that apparent power is due to the resistive loads in your computer and
hard drive; the true power is 42.5 Watts, or approximately the 41 Watts you
reported. There is little or no inductive and capacitive load. That makes
sense, because the hard drive motor was a major part of the inductive load
when it was connected.

So, you can see that the apparent power draw does decrease, from 51.2 VA to
42.5 VA, when you disconnect the hard drive.

Can somebody else explain why the true power (resistive load) -increases-
from 31 Watts to 41 Watts when the hard drive is disconnected?

Wayne

 

[Don Taylor From:]

"Wayne Farmer" <usenet@endymionsystems.com> writes:

So, you can see that the apparent power draw does decrease, from 51.2 VA to
42.5 VA, when you disconnect the hard drive.

Can somebody else explain why the true power (resistive load) -increases-
from 31 Watts to 41 Watts when the hard drive is disconnected?

Back in the ancient days, and thus this information may or may not apply
to the current day, computer power supplies had big heavy expensive iron
transformers. When the slightly more modern, but still ancient, "pc was
invented" transformers were replaced by lighter cheaper and often much
poorer quality switching supplies. The widespread knowledge of those old
days was that you NEVER turned on one of these supplies without some load,
typically having at least a 5" full height hard drive attached to do this.

Not having a load on a cheap low quality switching supply can lead to wild
and unhappy oscillation within the supply, often coming to an end in a few
seconds when you go and get a replacement for your supply.

Perhaps the supply operating without a load is demonstrating its unhappy
state by increasing dissapation by 35%+. Adding resistive load in small
increments and seeing whether the true power decreased before increasing
might help test this guess.

I once destroyed one of these supplies just by switching it off and then
back on too quickly.

 

[Lord Garth]

"Walter" <l.jinright@mchsi.com> wrote in message
news:MDnge.74149$WI3.58755@attbi_s71...

I just got a new one in an email a couple days ago, seemed to be fairly
new.
It was called sober.
Luckily I keep my Norton 2005 up to date.

"Rich Grise" <richgrise@example.net> wrote in message
newsan.2005.05.09.16.09.12.323858@example.net...
Subject: VIRUS WARNING!!!!!

The ISP has been killing this one....

 

[Lord Garth]

<for_england@hotmail.com> wrote in message
news:1115821078.656657.168100@f14g2000cwb.googlegroups.com...

I have read a few different definitions of sequential and combinational
and i still do not understand the difference between them. If anybody
could put the major difference/s into simpler terms i would be grateful

cheers
sam

Sequential logic means one operation after another happens in sequence.
This
is controlled by using a timing pulse or a clock. Clocks can be synchronous
meaning all devices are pulsed at the same time or the clock can ripple
through
the circuit meaning that the output from the first stage clocks the second
and so on.
It is generally better to design synchronous logic. Combinational logic
does not
use a clock. It uses a combination of logic gates to perform a task and is
asynchronous
to any system clock.

 

[Lord Garth]

<for_england@hotmail.com> wrote in message
news:1115827055.597463.13440@o13g2000cwo.googlegroups.com...

Thankyou very much thats a few extra marks i will gain on my exam
tommorrow!

Sam

Good luck on your test!

 

[Paul Jones]

I'm in Thailand .... Just bought 120 mikes for $6 .
They are cap type w/ built in FET amp .
But i'd still need a current amp for long distance .
There's plenty of voltage so just do a curr amp .
It makes the mike look like it's a 1 ohm mike !

 

[Paul Jones]

A virus is s/w that can use the malicious feature of
an op sys to replicate or destroy some other s/w .

Linux has no viruses . Only M$ .
It is impossible for Linux to do Virus for it was not written
maliciously .

 

[Paul Jones]

Do you want to learn C or MCU's ?

C is the worst HLL to program MCU's .
It is a special version that creates tiny code , nothing like the
big versions

There is nothing easier than FORTH and it has ALWAYS generated
tiny code .

There are many ppl trying to say FORTH is slow or bad or ....

FORTH is the fastest to write code , the fastest run time code .

 

[Paul Jones]

BW is rise time ! The fastestest portion of ur waveform
is the "BW" spec .
But the big deal is rise and settling time !

The LM357M is a very fast but high Vos drift op amp .
It settles 100 times faster than a traditional op amp
and has 20 mhz BW .

 

[Michael A. Terrell]

Paul Jones wrote:

A virus is s/w that can use the malicious feature of
an op sys to replicate or destroy some other s/w .

Linux has no viruses . Only M$ .
It is impossible for Linux to do Virus for it was not written
maliciously .

Yawn.
--
Former professional electron wrangler.

Michael A. Terrell
Central Florida

 

[Tom Biasi]

"jason" <cheanglong@gmail.com> wrote in message
news:1115835963.155333.121590@g44g2000cwa.googlegroups.com...

Hi All

Anyone can explain more about deriving a small signal model of any
mosfet or bipolar circuit configuration using two port amplifer and
thevenin theorem?

I do not understand this theory. ANyone can help by given a few
examples?

Any links to share?
Thank you

Jason

Hi Jason,
Where have you looked so far for info?
>

 

[Bob Monsen]

Paul Jones wrote:

Do you want to learn C or MCU's ?

C is the worst HLL to program MCU's .
It is a special version that creates tiny code , nothing like the
big versions

There is nothing easier than FORTH and it has ALWAYS generated
tiny code .

There are many ppl trying to say FORTH is slow or bad or ....

FORTH is the fastest to write code , the fastest run time code .

Well, I've written several FORTH implementations, and done large systems
in FORTH. It's a butt-ugly language. Unless you are quite careful, it's
nearly impossible to decipher a few minutes after you've written it. As
a consequence, it's often called a write-only language.

Some of the nice things about FORTH are that multithreading is trivial,
since it often has a built-in scheduler; the interpretive nature makes
it great for hardware hacks, probing registers, and the like; it can be
made very fast and small because of the way the 'interpreter' (ie, NEXT)
works.

I've never seen a good debugger for FORTH, though. They may exist, but
the ones I've seen are always clumsy and annoying to use.

There is at least one FORTH for the PIC; there may be more. There is
also a free C compiler (the hitech C compiler) that you can download.
Using either that or just MPASM will be far easier and more intuitive
than using FORTH, unless you have a masochistic/obsessive streak.

---
Regards,
Bob Monsen

 

[Matt Flyer]

jason wrote:

Hi All

Anyone can explain more about deriving a small signal model of any
mosfet or bipolar circuit configuration using two port amplifer and
thevenin theorem?

I do not understand this theory. ANyone can help by given a few
examples?

Any links to share?
Thank you

Jason

I would recommend that you start with a book on micro-electronic

circuits that covers dependant sources. It has been a few years, but if
my memory serves, the small signal models typically model the transistor
as a dependant source conencted with models of the input and output
impedance. The models generally assume that the device is biased so
that it is operating in the linear region.

Sorry if this doesn't help much.

One book that I found to be very helpfull in explaining transistors in
"real world" terms is "The Art of Electronics". Some books I have
encountered try to teach you to rely on paramaters that vary all over
the place like a bjt's Beta, but this one doesn't.

 

[Joel Kolstad]

"Dr Engelbert Buxbaum" <engelbert_buxbaum@hotmail.com> wrote in message
news:d5n7iu$t4c$01$1@news.t-online.com...

This is something I have always wondered about: People worry about
electromagnetic fields from the towers, but happily place a mobile phone
against their head (or allow their children to do so), which produces
much higher field strengths.

Actually, plenty of people worry about the handsets as well. The people who
only seem worried about the towers are probably really just coming up with an
excuse for why they don't want what they consider to be an ugly structure in
their neighborhood.

And note that mobiles produce electric fields all the time (to keep the
contact with the net), not only while you are actually phoning with
them.

True, but the human body models for specific absorbed radiation (SAR) make
measurements based on the "total dose" of electromagnetic power. This is
orders of magnitude lower when the phone just has to respond to an occasional
"ping" from the tower than when you're actively talking.

 

[R. Steve Walz]

alismans wrote:

I am trying to use the programmer from

http://members.aon.at/electronics/pic/picpgm/index.html

I have built the circuit
picpgm_cable according to the diagram. I have used a
74LS04 instead of 74ALS05
-----------------------

They are totally different parts, it won't work without the '05.
The '05 is open-collector, totally different.

because this is what was
available. I then run the software WinPicPgm and on
the status line at the bottom there is a message
"No pic programmer found".
Can you help me?
thanks!!

-Steve
--
-Steve Walz rstevew@armory.com ftp://ftp.armory.com/pub/user/rstevew
Electronics Site!! 1000's of Files and Dirs!! With Schematics Galore!!
http://www.armory.com/~rstevew or http://www.armory.com/~rstevew/Public

 

[Ratch]

<for_england@hotmail.com> wrote in message
news:1115821078.656657.168100@f14g2000cwb.googlegroups.com...

I have read a few different definitions of sequential and combinational
and i still do not understand the difference between them. If anybody
could put the major difference/s into simpler terms i would be grateful

cheers
sam

From Digital Design by M. Morris Mano

"A combinational circuit consists of logic gates whose outputs at any
time are determined directly from the present combination of inputs without
regard to previous inputs. A combinational circuit performs a specific
information processing operation fully specified logically by a set of
Boolean functions. Sequential circuits employ memory elements in addition
to logic gates. Their outputs are a function of the inputs and the state of
the memory elements. The state of the memory elements, in turn, is a
function of previous inputs. As a consequence, the outputs of a sequential
circuit depend not only on present inputs, but also on past inputs, and the
circuit behavior must be specified by a time sequence of inputs and internal
states." Synchronous/asynchronous clocking pertain only to sequential
logic. Ratch

 

[Lord Garth]

"R. Steve Walz" <rstevew@armory.com> wrote in message
news:4282D1FB.4C76@armory.com...

alismans wrote:

I am trying to use the programmer from

http://members.aon.at/electronics/pic/picpgm/index.html

I have built the circuit
picpgm_cable according to the diagram. I have used a
74LS04 instead of 74ALS05
-----------------------
They are totally different parts, it won't work without the '05.
The '05 is open-collector, totally different.


because this is what was
available. I then run the software WinPicPgm and on
the status line at the bottom there is a message
"No pic programmer found".
Can you help me?
thanks!!

Wow! That one is way old Steve....are you just getting it?

 

[colin]

<ganjatoker@gmail.com> wrote in message
news:1115896088.785447.279840@z14g2000cwz.googlegroups.com...

I'm curious as to how the term "live" came to refer to an energized
circuit. It is somewhat of a contradiction, as touching a live wire has
the potential of making someone dead! I can however, see how the term
expresses the idea that the circuit has a certain quality of "life" to
it. I've tried checking etymological sources but the most mentioned is
that the term came about around 1890, which would make sense.

Thanks!

I gues the opposite is when you 'kill' the power.

Colin =^.^=

 

[Jeroen]

"Jonathan Kirwan" <jkirwan@easystreet.com> schreef in bericht
news:d496819713cigfdihkvdvcptqq17frd24t@4ax.com...

On Wed, 11 May 2005 23:25:46 -0500, "Ratch" <Watchit@comcast.net
wrote:

From Digital Design by M. Morris Mano

"A combinational circuit consists of logic gates whose outputs at
any
time are determined directly from the present combination of inputs
without
regard to previous inputs. A combinational circuit performs a specific
information processing operation fully specified logically by a set of
Boolean functions. Sequential circuits employ memory elements in
addition
to logic gates. Their outputs are a function of the inputs and the state
of
the memory elements. The state of the memory elements, in turn, is a
function of previous inputs. As a consequence, the outputs of a
sequential
circuit depend not only on present inputs, but also on past inputs, and
the
circuit behavior must be specified by a time sequence of inputs and
internal
states."

When I saw the OP's glee at getting an answer for a test from here
(without trying to really understand it) I decided against saying
anything more just then. It appears the test may be over now, so:

To put it simply without distorting too much, combinatorial logic
doesn't have state and sequential logic does.

What about a 2 gate S/R flipflop? Or does logic with feedback not qualify as
combinatorial?

Jeroen

 

[Jeroen]

<simoung@gmail.com> schreef in bericht
news:1115910184.785506.110700@g43g2000cwa.googlegroups.com...

My Technos water purifier/ionizer refuses to turn itself off. After
inspecting I've found a stuck closed voltage regulator. I'm trying to
locate a compatible regulator. Where can I find a voltage regulator
replacement for this one?

Thanks.
FW0128 FQP W 50N06
Details problem see http://snipurl.com/eu3m

This is not a voltage regulator but a N channel MOSFET. Datasheet at
http://www.fairchildsemi.com/pf/FQ/FQP50N06.html

FW0128 is probably some production date code. The 'W' seems to be the
Motorola logo. So the full part number is FQP50N06.

Hope this helps,
Jeroen