Chip with simple program for Toy

[peterken]

simple....
so they can charge you more since everybody uses more as 160




<prince_nsa@yahoo.com> wrote in message
news:1098946791.066894.50740@c13g2000cwb.googlegroups.com...
why sms is only 160 characters?

 

[John Larkin]

On 28 Oct 2004 20:34:08 -0500, me <me@here.net> wrote:

But I'm impressed that you're actually verifying your simulations by
experiment; some people just quit when the sim works.


John


Don't be. If they didn't have to build it to demonstrate it in the lab
they would have called it good after the simulation.

I resently had a tour of the EE department at Cornell University. I
figure that computer screens outnumber oscilloscope screens by roughly
15:1.

John

 

[Robert Monsen]

Erik Durling wrote:

We're a couple of students doing an electronics project. We are to
construct a battery indicator circuit. We had a finished circuit on
paper and we had simulated it with Multisim 7. But when we tested the
circuit in real life, it didn't work at all like we had planned (or
according to simulation). The circuit was based upon the idea of
zenerdiodes having a constant voltage drop, and not conducting if the
circuit isn't able to supply the needed voltage across it. But the
zener-diodes doesn't stop conducting at all, and the voltage drop is
far from constant.

This is the main circuit: http://ersker.com/circuit.gif

The zener diodes used in real life are: BZX55 and not BZC55, but that
ought not change anything (right?).

We did a DC Transfer Analysis in the simulator and got three nice
curves showing the voltage at the three collectors (compared to
ground) as the voltage from the source goes from 0-4.5 volts, and
everything seems right there: http://ersker.com/dctrans.gif

So, the problem we're having with our real circuit is that the LEDs
never turn off (the transistors are always saturated). The zener
diodes doesn't stop conducting when the voltage across them goes under
their specified value.

What's our mistake/misconception?

Do the zeners only operate correctly at a certain current?

Well. Here is a funny thing. I just simulated a circuit with a variable
voltage source across a 1k resistor, connected to a 3.3V zener, and then
to ground. The voltage source goes from 0 to 10V in 10 seconds. Oddly,
the junction between the resistor and zener starts out at 2.3V, and goes
up slowly from there. Thus, it appears that spice believes that the
zener diode is a voltage source This happens for both circuitmaker and
LTSpice. There is actually current flowing backwards through the
resistor into the voltage source until the dc source gets to equal the
'voltage source' of the zener. I'd say that the spice implementation of
zener diodes of low value is seriously flawed when used with a voltage
lower than the actual zener voltage minimum.

Here is the spice netlist:
* node0--[V1=PWL]--node3--[R1=1k]--node4--[XD1=1N5226B]--node0--GND
*
*Spice netlist for Circuit: C:\CM60S\Circuits\UNTITLED.CKT
V1 3 0 DC 0 PWL( 0 0 10 10)
XD1 0 4 X1N5226B
R1 4 3 1k
..SAVE V(3) V(4) @v1[p] v1#branch @r1[p] @r1
*BKGND=RGB 0 0 0
*BINARY RAW FILE

* Selected Circuit Analyses :
..TRAN 20m 10 0 20m

* Models/Subcircuits Used:

*1N5226B 3.3V 500mW Si pkgIODE0.4 A,K
..SUBCKT X1N5226B 1 2
D1 1 2 DF
DZ 3 1 DR
VZ 2 3 2.536
..MODEL DF D (IS=2.51N RS=84M N=1.7 CJO=182P VJ=0.75 M=0.33 TT=50.1N)
..MODEL DR D (IS=5.59M RS=8.4 N=15)
..ENDS X1N5226B
..END

--
Regards,
Robert Monsen

"Your Highness, I have no need of this hypothesis."
- Pierre Laplace (1749-1827), to Napoleon,
on why his works on celestial mechanics make no mention of God.

 

[Rich Grise]

On Fri, 29 Oct 2004 15:59:40 -0400, Mike wrote:

Here's an interesting post with a guy that never experienced a GFCI trip
with all sorts of appliances, including fluorescent fixtures:
http://fins.actwin.com/aquatic-plants/month.200205/msg00752.html

To answer your question: if voltage is draining to ground, you have a
short somewhere. Doesn't necessarily mean that your switch is not
grounded. If you had a bad switch that was leaking current to its metal
frame, which wasn't grounded, you'd most likely get zapped. Here's how a
GFCI looks internally (you can infer operation from this):
http://homerepair.about.com/library/graphics/gfci_schematic.jpg

I'm not too familiar with ballast internals. Sorry. Perhaps your GFCI is
too sensitive?

That would have been my first guess. It's tripping on the glitch.

Try a little snubber across the switch, say 1K 1W in series with
about 1-10 nF, 600V.

Good Luck!
Rich

 

[John Popelish]

Erik Durling wrote:

jpopelish@rica.net (John Popelish) wrote:
How low does the battery voltage have to go before the LEDs turn
essentially off?

The fresh-voltage is about 4.5, then one LED turn off every 0.5 volt.
Though we have potentiometers connected between the two resistors in
the picture (and the values differ a little), but I left that out on
purpose, those values aren't that important for the "problem".

I am suspicious that you may have the zeners backward.

Isn't that the point with zeners (that they're backwards)?

But using a comparator (comparing your divider voltage to a fixed
reference instead of a transistor sensing zener current) would give
a
lot cleaner threshold.

That was what we planned to use at first, but they themselves needed a
higher voltage than the battery was able to provide (less than 3 volts
at minimum).

These work down to 2.7 volts:
http://cache.national.com/ds/LM/LMV331.pdf
--
John Popelish

 

[Dmitri(Cabling-Design.com]

prince_nsa@yahoo.com wrote:

why sms is only 160 characters?

Maybe guys in comp.dcom.telecom.tech group can answer that?

We keep this group archived here:

http://www.cabling-design.com/forums/newsgroup14-.htm

Good luck!


--
Dmitri Abaimov, RCDD
http://www.cabling-design.com
Cabling Forum, color codes, pinouts and other useful resources for
premises cabling users and pros
http://www.cabling-design.com/homecabling
Residential Cabling Guide
-------------------------------------




##-----------------------------------------------##
Article posted with Cabling-Design.com Newsgroup Archive
http://www.cabling-design.com/forums
no-spam read and post WWW interface to your favorite newsgroup -
sci.electronics.basics - 5094 messages and counting!
##-----------------------------------------------##

 

[Ken]

On 27 Oct 2004 23:59:51 -0700, prince_nsa@yahoo.com wrote:

why sms is only 160 characters?

SMS = Short Message Service
Yes "short"!

http://www.btinternet.com/~mrbush/old/sms.htm

The inventors did not know that the SMS service would be so popular
many years later.

 

[Joe]

Visit http://www.fact-index.com/r/ro/rogowski_coil.html

or for some rogowski specs http://www.rocoil.cwc.net/Spec8000.PDF


--
Joe
http://www.fcctests.com

"Randy Gross" <aaawelder@yahoo.com> wrote in message
news:d76ab107.0410292116.1945e7b5@posting.google.com...

I am trying to gain a better understanding of the principles of the
Rogowski coil.
I understand that an AC current carrying conductor running through
this coil induces a voltage in the coil proportional to the rate of
change of current in the conductor which can be measured with a DVM.
What I'm having a problem with is the integrator associated with its
use. Is this necessary for frequencies above 60HZ or any range? Can
this coil be calibrated to read say 1vac at 1amp AC 60HZ as a basis
and then be used over a wider range?

Wondering

 

[John Fields]

On 30 Oct 2004 07:21:49 -0700, tek1940@hotmail.com (George) wrote:

Thanks Tom and others for your info.
I guess this poster (me) is at a beginner level.
Learning OHM's law, relationship between each value and trying to
confirm with a 9V battery, resistors and MM.

Using letter R to represent ohms, showing Law and actual MM readings
at decreasing levels of magnitude:

Law: .06 mA = 8.2 V / 118,500 R
MM: .06 mA

Law: .556 mA = 8.2 V / 14/730 R
MM: .556 mA

Law: 3.79 mA = 8.2 V / 2162 R
MM: 3.75 mA (99% of Law)

Law: 55.40 mA = 8.2 V / 148 R
MM: 52.1 mA (94% of Law) ***

Law: 83.25 mA = 8.2 V / 98.5 R
MM: 76.5 mA (92% of Law) ***

Law: 138 mA = 8.2 V / 59.4 R
MM: 120 mA (87% of Law) ***

Law: 332 mA = 8.2 V / 24.7 R
MM: 253 mA (76% of Law) ***

---
Since you haven't mentioned anything to the contrary, it seems you're
_assuming_ that the battery voltage will remain constant at 8.2V
regardless of the load on it. It won't.

You also seem to be having trouble with the concept of the internal
resistance of the battery. Consider it a variable resistance in
series with the battery, located in the same housing as the battery,
but which you can't physically get to.

But, you _can_ measure it. Consider:

+----------+
| |
+---|----+ |
| | | |
| [R1] | |
| | | [R2]
| |+ | |
| [BAT] | |
| | | |
+---|----+ |
| |
+----------+

Where R1 is the internal resistance of the battery, BAT is the stuff
in the battery making the voltage, and the box around them indicates
that they are inseparable. But, let's go ahead and separate them
anyway, just for fun, like this:

+-----+---->E1
| |
| [R1]
|+ |
[BAT] +---->E2
| |
| [R2]
| |
+-----+---->

Now, let's assume that the stuff in the battery makes BAT a true
voltage source which can supply an infinite current into a zero ohm
load. If that's true, then the current BAT can supply into R1 and R2
will only be limited by the sum of the resistances according to Ohm's
Law:

E
I = ---
R

which, in this case, becomes


E1
I = ---------
R1 + R2


Using your data, we can say that in all cases E1 will be 8.2V, and if
we retabulate the data for convenience we get:

VOLTS mA OHMS
E1 I R2
-------|-------|--------

8.2 0.06 118500

8.2 0.556 14730

8.2 3.75 2162

8.2 52.1 148

8.2 76.5 98.5

8.2 120 59.4

8.2 253 24.7


If we rearrange I = E/R to solve for resistance we get:


E
R = ---
I

and if we plug in the first set of values you got we get:


E 8.2V
E = --- = ------ = 136667 ohms
I 60ľA


Notice that the resistance you used to get that 60ľA was 118500 ohms,
some 18167 ohms short of what Ohm's law says it should be, and since
Ohm's law doesn't lie, where did that resistance come from?

From inside the battery, and it's the resistance we're calling R1

Continuing in the same vein and filling out the rest of the table, we
wind up with:

VOLTS mA OHMS OHMS OHMS
E1 I RT R2 R1
-------|------|--------|--------|-------

8.2 0.06 136667 118500 18167

8.2 0.556 14748 14730 18

8.2 3.75 2186 2162 24

8.2 52.1 157 148 9

8.2 76.5 107 98.5 8.5

8.2 120 68.3 59.4 8.9

8.2 253 32.4 24.7 7.7


Notice that R1 is the internal resistance of the battery, and notice
that it changes with load.
---

*** At these levels, the MM showed initial 473 mA then the number
shown here then decreasing values. At the 24.7 R test, the rate of
decrease was in larger increments than at 148 R.

Did not proceed with lower R values because MM manual says it can read
max 400 mA.
In bottom two levels, I learned how to put resistors in Parallel and
calculate the net resistance. (98.7 and 148.7 for 59.4 R; 4 x 98.7
for 24.7 R)

Q1. Is the apparent error percentage due to my MM or would all meters
show these variances?

---
A1. Different ammeters would show the same variances if they all had
the same internal resistances.
---

Q2. Same question but regarding the "decreasing value" behavior.

---
A2. Same answer
---

Q3. If the meter could read larger amounts of current, and I used
lower amounts of R, the Law predicts higher current.
Law: 4.1 A = 8.2 V / 2 R
Can an 8.2 V battery produce 4.1 A?

---
A3A. If it has a low enough internal resistance and the resistance of
the load is also low enough, yes.
---

Is there an additional math factor needed in the Law to filter out
"impossible" results?

---
A3B. No, just proper reasoning.
---

Q4. Continuing to lower R to Almost zero (metal of the MM lead wires),
if the MM can read up to 400 mA, why isn't it safe to measure the
current of a 9 V battery?

---
A4A. The reason you shouldn't connect an ammeter directly across a
battery is because the internal resistance of the battery may be very
low, which will allow a large current to flow through the meter. Then,
if the meter isn't protected by a fuse, it could be damaged.
---

Is there another way to find available current?

---
A4B. Measure the [momentary] short-circuit current using a shunt.

--
John Fields

 

[CFoley1064]

Subject: Single Supply Op-Amp
From: "Ken McDonald" sorry.no@email.com
Date: 10/30/2004 11:26 AM Central Daylight Time
Message-id: <lhPgd.1977$vH5.1958@fe1.columbus.rr.com

Can someone recommend a single supply op-amp with better specs than an
LM358?

Thanks,

Ken McDonald

Lots of them.. What do you need?

Chris

 

[John Larkin]

On 29 Oct 2004 11:52:08 -0700, egd.bydalen@swipnet.se (Erik Durling)
wrote:

I think I explained the purpose of the zener improperly. We have it
there to increase the potential needed to saturate the transistor so
it needs a smaller change in the source to turn off the LED.
But the "leakage" was still the big problem eitherway.

A base-emitter resistor will help a lot.

John

 

[Ken McDonald]

"CFoley1064" <cfoley1064@aol.com> wrote in message
news:20041030140637.21100.00002848@mb-m07.aol.com...

Subject: Single Supply Op-Amp
From: "Ken McDonald" sorry.no@email.com
Date: 10/30/2004 11:26 AM Central Daylight Time
Message-id: <lhPgd.1977$vH5.1958@fe1.columbus.rr.com

Can someone recommend a single supply op-amp with better specs than an
LM358?

Thanks,

Ken McDonald



Lots of them.. What do you need?

A single supply dual op-amp with higher gain and higher slew rate. The
output goes to ground. Better specs all around than an LM358. I will be
using the op-amp in a variety of different circuits.

Ken

Chris

 

[Rich Grise]

On Sat, 30 Oct 2004 18:28:22 +0000, Ken McDonald wrote:

"CFoley1064" <cfoley1064@aol.com> wrote in message
news:20041030140637.21100.00002848@mb-m07.aol.com...
Subject: Single Supply Op-Amp
From: "Ken McDonald" sorry.no@email.com Date: 10/30/2004 11:26 AM
Central Daylight Time Message-id:
lhPgd.1977$vH5.1958@fe1.columbus.rr.com

Can someone recommend a single supply op-amp with better specs than an
LM358?

Thanks,

Ken McDonald



Lots of them.. What do you need?

A single supply dual op-amp with higher gain and higher slew rate. The
output goes to ground. Better specs all around than an LM358. I will be
using the op-amp in a variety of different circuits.

Chip manufacturers used to have parametric selector guides on their sites.

I've been out of the loop, so don't even know who makes chips anymore, but
I can't imagine there _not_ being something out there.

In my day, the biggies were TI and National, with a sprinkling of Motorola
and Sprague. Maybe they have links.

TI TL082? Nat'l LM324?

Good Luck!
Rich

 

[Rich Grise]

On Sat, 30 Oct 2004 10:28:06 -0400, OH YEAH wrote:

"William J. Beaty" <billb@eskimo.com> wrote in message

Drill a hole in your oven wall! It lets you reach in with a plastic
stick and poke at sizzling sample-objects. Or stick an NE2 bulb in the
end of a soda straw and explore the 3D hotspot pattern.

Don't drill a hole in your oven.

Microwaves are by no means - my specialty, so my assumption here could be
wrong.... But I'm wondering.... the hole on "top" of the microwave maybe
being "above" the main oven components - was still "shielded" from the
"active" parts? Where as the door was inline with the deflected
microwaves? Just a guess.

No, actually, it is because up to a certain size, the microwaves don't
even realize that there's a hole there. It's too small for them to
get through, just like the holes in the door grille.

This is also why ants don't cook. ;-)

Cheers!
Rich

 

[Roger Johansson]

"John G" <Greentest@ozemail.com.au> wrote:

supply is 220V DC with ground here, it would not be a problrm to plug

You say the supply is 220volts D C ????
I doubt this is true but if it is you are in deep deep trouble.
Your US AC dryer will only issue magic smoke on DC.

http://www.spanishpropertyco.com/61.htm

"The majority of Electricity in Spain is supplied at 220 volts AC with a
frequency of 50 cycles per second."


--
Roger J.

 

[Roger Johansson]

A nice overview of the electrical systems and plugs in the world:

http://www.wordiq.com/definition/Power_plug
scroll down for maps

230 Volt 50Hz is the standard in practically all of the world.
"230V" includes 220-240V, moving toward 240V in the long run.

The exception is the US-dominated part of the world: North America, parts
of Latin America, and Saudi Arabia. 110 Volt 60 Hz.

Korea, Japan, Madagaskar, and a few other small places have other
mixes of the same voltages and frequencies. (110V 50Hz and 230V 60Hz)

See also:
<http://encyclopedia.thefreedictionary.com/List%20of%20countries%20with%20
mains%20power%20plugs,%20voltages%20&%20frequencies>

The countries which earlier used 220V are moving up towards 240V.
In my country we had the 220V norm earlier, but changed to 230 norm and
the real measured voltage now is actually around 235V.


--
Roger J.

 

[Spajky]

On 30 Oct 2004 13:58:59 -0700, cecile.frederic@telefonica.net
(Frederic C) wrote:

I have bought a Whirlpool Dryer in the US, and I have now moved to
Spain. I have brought my dryer with me, thinkiing that as the power
supply is 220V DC with ground here, it would not be a problrm to plug
it.

You have to find an 220V~/110V~ power adapter if you can find it in
some local electric shop (I have something like this, its a 5x7x3cm &
can handle 1,4kW- dun`no whats inside) ... but maybe that adapter
would be hard to find & less expences would be getting another
hairdryer IMHO ...
--
Regards, SPAJKY ÂŽ
& visit my site @ http://www.spajky.vze.com
"Tualatin OC-ed / BX-Slot1 / inaudible setup!"
E-mail AntiSpam: remove ##

 

[petrus bitbyter]

"Chris Williams" <thesagerat@yahoo.co.jp> schreef in bericht
news:da271e02.0410270107.6175782c@posting.google.com...

I am teaching myself from Thomas L. Floyd's "Principles of Electric
Circuits". So far (chapter 4) it seems that he has done a good job
describing all of the units and how they should be visualized except
for Joules (energy.) This he pretty much just says is "the amount of
available energy" but without making it any clearer.

It would appear that fundamentally everything boils down to 1.) the
quantity of electrons (Q), 2.) time (t), and 3.) energy (W.)

Q = Total quantity of electrons
t = time spent doing something with the electrons
W = "the amount of available energy"

So current is easy:
I = (number of electrons) / (time)
Rate at which electrons were moved (through a wire)

But voltage is problematic:
V = (W?) / (number of electrons)
Rate of "the amount of available energy" to the number of electrons
...which isn't terribly clear

Reading over the text a couple of times, and I am thinking that
voltage is the electrical version of "pressure"...?
So in water/piping terms, pressure would be a function of a) the
amount of water and b) the amount of "push" it had to make it want to
go into a pipe. Push would then be a product of gravity, mechanical
pumping, etc. So assuming that this is true then W == "Push."

Pressure = "Push"(kg) / Water(cm^2) for instance

So this allows me to understand a Volt

Voltage = "Push"(joules) / Electrons(coulomb)

But what is the electric version of "push"?
My current guess is that this is the total "negativity" or
"positivity" of a terminal on a power source. Which--in the case of a
battery say--would be the ratio of positively charged atoms to neutral
atoms in a positive electrode, or the number of free electrons to the
total number of neutral atoms in the negative electrode...?

Is this reading correct?

Thank you,
Chris Williams

Chris,

Voltage is often compared with pressure and it's not a bad comparison. But I
guess your description of pressure is not correct so you will fail to
understand voltage as well. Pressure has nothing to do with amount. The
"potential" of water depends on its height (due to gravity) no matter the
amount of water. It may be either a raindrop or a reservoir. Only if you
look at the energy the amount becomes important.

Power has to do with the available energy per second. Even a filled
reservoir can deliver little energy/second if you have only a 1" pipe. But
when the weir breaks... Another example is a flashlight battery. Its amount
of energy is comparable with the energy of a thunderflash but you need at
least minutes to empty a battery. A flash delivers its energy in a split
second.

petrus bitbyter



---
Outgoing mail is certified Virus Free.
Checked by AVG anti-virus system (http://www.grisoft.com).
Version: 6.0.778 / Virus Database: 525 - Release Date: 15-10-2004

 

[Jack Hayes]

"news" <news@abc.com> wrote in message
news:1Kednc23Lvgh0RncRVn-oQ@rogers.com...

Im an amateur/novice at electronics. Mostly I'm interested in electronics
to
fix things and make life a little easier around the house.

My problem is that I have a light that is on a switch outside the house. I
want to turn it on and off from inside the house. It's in an awkward place
and makes it hard and unsightly to run 120v Wires and switch box etc. into
the house. I would like to build an electronic switch that would only
require me to run a small wire to an electronic switch from the light into
the house. Can anyone point me to a schematic for this type of thing that
I
can build. I want the switch to provide its own power to the low voltage
switch in the house. I don't want to be fussing with some sort of AC/DC
adapter to provide the switch power.

Can anyone help me out.

Thanks.

You could do this with an RF (wireless switch) and not require any installed
wiring. These are available in Canada for turning on car engine heater in
the winter without going outdoors.

Jack

 

[news]

Interesting idea. Yes I know that I will have to still use some wire. It
will just be so much easier with smaller gage. I can run it into the house
put it along baseboards etc. I would still like to use a small electronic
switch with low voltage wire. Can anyone point me to where I can find this
kind of thing.

Thanks.