Chip with simple program for Toy

"Bill Bowden" <HoldenCaulfield@att.net> wrote in message news:401eed4d.0307180803.2e3bfcb1@posting.google.com...

engi> wrote in message news:<bf78de01hhn@enews2.newsguy.com>...
Good explanation, so we have 10K connected to ground, the other one,
the 1K, is connected to +V , so still - they are not in parallel ?

Yes they are in parallel from a signal point of view.
The 1K resistor is grounded through the power supply.
+V and ground are the same points for AC signals.

Think about a bypass capacitor placed across the circuit
from +V to ground. It connects the two points together.

-Bill

Wow, this is great. Electronics is full of those nasty tricks.
I really didn't know that, but your explanation with the
capacitor was an eye opener. Many thanks
(mind you, in three years at uni no one has ever mentioned
this)

 

[Arthur Jernberg]

Any good TV schematic will show the basic diagram of current tuners. Even a
Google Search should turn up some interesting information for you.
"Michael Drainer" <drainer@sbcglobal.net> wrote in message
news:EWUQa.1257$rv.340@newssvr23.news.prodigy.com...

Can anyone provide schematics for a basic TV tuner?

Thanks

 

[Watson A.Name - 'Watt Sun]

In article <_pYRa.31932$k85.1364351@twister.tampabay.rr.com>,
aichipREM@OVEcfl.THISrr.com mentioned...
[snip]

This proportional changes was used by Hewlett and Packard when they invented
their popular 202 oscillator. And another common non-ohmic device is a LED.

I believe the 202 wasn't their first osc. I used a HP 200CD audio osc
back in the '60s when I worked for a radio eng'g lab and it wasn't the
earliest.

That is why almost every LED requires a series resistor to limit its current.
At a given voltage, it will lower its resistance and go into thermal runaway,

Whoops! You should not have said "lower its resistance". You should
have said, it will lower its voltage drop. After all, it's not an
ohmic device.

destroying itself. As for the small LED flashlights with the button cells, the
batteries themselves provide an intrinsic resistance that limits the current,
and so they often have no resistors.
You will find that semiconductor junctions in general are all non-ohmic
devices, along with lamps and Nernst glowers. So are gas discharge tubes, etc.

This is the first I've heard of the Nernst glower - never heard of it
before. I did a google search and found this site, which tells a lot
about this German guy. I remember that when I was in Germany, a lot
of stuff had AEG on it.

http://www.nernst.de/

Tell me. Do you believe in negative resistance?

Cheers!

Chip Shults
My robotics, space and CGI web page - http://home.cfl.rr.com/aichip

--
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[Ratch]

"buck rojerz" <inorbit@outerspace.org> wrote in message
news:Xns93BC82E2AE949ou812@216.168.3.44...

"Ratch" <Watchit@Comcast.net> wrote in
news:BZmRa.80118$Ph3.9181@sccrnsc04:


"Mark D. Zacharias" <mzacharias@nospam.earthlink.net> wrote in message
news:4BmRa.5630$Mc.475640@newsread1.prod.itd.earthlink.net...
Yes, and Ohm's Law describes the interaction of resistance, voltage,
and current. Not just resistance.
I'm not an engineer, granted, but I don't require an education on
Ohm's
Law.

Mark Z.

I belive that you are missing the point. The resistance (or
impedance)
formula V=IR (or V=IZ), describes the describes the interaction of
resistance (impedance), voltage, and current. While correct and true
in all cases, those formulas are NOT Ohm's law, and it is wrong to
call them that. As shown in the second link I gave, Ohm's law is a
property of resistive linearity in a material. Just as the specific
gravity of a material is a property. If it conforms to Ohm's law, it
is ohmic. Otherwise it is nonohmic. Ratch


What the heck is "nonohmic"? Is this a word you just made up? I have
been
an electronis tech for 30+ years and thats a new one on me.

I posted this site before, which answers your question.
http://www.launc.tased.edu.au/online/sciences/PhysSci/done/electric/resistnc/Resistance.htm
Did you read it?

It all doesn't
matter. Wether it is inductance, capacitive impedance, a thermistor, a
varistor, or what ever. Ohm's law still stands firm.

The resistance formula R=V/I stands firm. Ohm's law is a property of a
material, as explained in the above link, and is not an equation.

For changing
"impedance" or fixed resistance. At any moment in time, there is a
certain
resistance(impedance), a certain voltage and a certain current and ohm's
law always applies. Even in a combined circuit of capacitance and
inductance with an appplied frequency signal. At 1 instantaneous moment,
there is a vectored impedance and associated voltage and current.

Impedance is not a vector, it has magnitude but no direction. Impedance has
magnitude and phase and is often described as a phasor, which has some
vector like properties.

It is a
law of physics and there is no getting around it no matter what you call
it. A rose is a rose is a rose.

Yes, the resistance formula is R=V/I is R=V/I.

Here are the formulae and you believe what you will.

You are having a hell of a time posting that chart, are you not. In any
case, I agree with the relationships indicated by all the formulas. I do
not agree with naming them Ohm's law. Ratch

 

[Dan Fraser]

See my web site below

--
Dan Fraser

From Costa Mesa in sunny California
949-631-7535 Cell 714-420-7535

Check out my electronic schematics site at:
http://www.schematicsforfree.com
If you are into cars check out www.roadsters.com

 

[Dan Fraser]

Diodes and caps are semi passive and passive components. You need some
transistors and/or ICs first. Then diodes and caps.

--
Dan Fraser

From Costa Mesa in sunny California
949-631-7535 Cell 714-420-7535

Check out my electronic schematics site at:
http://www.schematicsforfree.com
If you are into cars check out www.roadsters.com

 

[Dan Fraser]

Do NOT use WD-40 to clean controls."WD" means "Water Displacer" It is
meant for drying stuff out. Its not even a good lubricant. It does leave
a residue behind that will attract more dirt and in a few weeks you will
be as bad off as before. WD-40 is a wonderful product to loosen up a
sticky lock or the like but it is a horrible contact cleaner.

--
Dan Fraser

From Costa Mesa in sunny California
949-631-7535 Cell 714-420-7535

Check out my electronic schematics site at:
http://www.schematicsforfree.com
If you are into cars check out www.roadsters.com

 

[Dan Fraser]

About 2 transistors per square cm. Its called a printed circuit board.

Even an old LSI like an 8088 processor with 29,000 transistors requires
a plant with a $50,000,000 price tag. A Pentium 4 factory costs
$2,000,000,000

However, there are silicon foundries in Taiwan who will make a custom
VLSI for you. The first one may be as cheap as $100,000. Each one after
will be about $1.00.


--
Dan Fraser

From Costa Mesa in sunny California
949-631-7535 Cell 714-420-7535

Check out my electronic schematics site at:
http://www.schematicsforfree.com
If you are into cars check out www.roadsters.com

 

[Gert van den Heuvel]

"John Smith" <pleasepostonly@pleasepost55555.com> wrote in message
news:sW4Sa.69446$Ho4.391941@news.easynews.com...

I have a basic transistor question. In an existing low-power 5V circuit, a
push button switch grounds a microcontroller's input line when pressed.
The
line is internally pulled up.

I want to allow an NPN transistor to simultaneously switch this IO line
(pull it down as needed) The logic of the transistor base can be inverted
or
not. How should I do this?

I was thinking of connecting the emitter to ground, collector to IO line,
so
HIGH at the base would pull the line down, and low would allow it to be
pulled up, but this seems too simple to be correct (see below)...Am I
missing something? Can anyone help?


-----------+---------> INPUT (internal pull-up)
R1 /C + |
---+\/\/+--| B |- Button
\E + |
| |
GND GND


Hi John,

Not all simple ideas have to be incorrect... I think your idea should work
perfectly.
Just give it a try; you won't damage anything.

--
Gert van den Heuvel
webmaster www.HobbyElectronics.info

 

[Roger Johansson]

"John Smith" <pleasepostonly@pleasepost55555.com> wrote:

I was thinking of connecting the emitter to ground, collector to IO line, so
HIGH at the base would pull the line down, and low would allow it to be
pulled up, but this seems too simple to be correct (see below)...Am I
missing something? Can anyone help?


-----------+---------> INPUT (internal pull-up)
R1 /C + |
---+\/\/+--| B |- Button
\E + |
| |
GND GND

You are right. It is that simple.

Use a base resistor which has a suitable value, so you don't burn the
transistor but you make sure it is fully on when you take the base
high. For a normal npn transistor you might want to try 2kOhm, for
example.

The only questionable phrase in your message was:

The logic of the transistor base can be inverted or not.

I am not sure what you meant, but you did everything else right so
there is probably no problem.

The logic of a bipolar transistor in this kind of circuit (a common
emitter circuit) is always inverting, the input signal goes high, the
output goes low.

Maybe you also think about an emitter follower circuit, and that is a
non-inverting way of using a transistor.

If that is what you meant you are 100% right.

--
Roger J.

 

[Mark D. Zacharias]

To a technician, Ohm's Law is the set of mathematical operations which
predict the behavior of voltage, current, etc. After using them for so many
years, I think it's understandable that a tech would only think of the
formulas and not the simple "mission statement" which would be the
"statement" of Ohm's Law. I'll stick with the formulas, thank you.

Mark Z.

"Ratch" <Watchit@Comcast.net> wrote in
news:BZmRa.80118$Ph3.9181@sccrnsc04:


"Mark D. Zacharias" <mzacharias@nospam.earthlink.net> wrote in message
news:4BmRa.5630$Mc.475640@newsread1.prod.itd.earthlink.net...
Yes, and Ohm's Law describes the interaction of resistance, voltage,
and current. Not just resistance.
I'm not an engineer, granted, but I don't require an education on
Ohm's
Law.

Mark Z.

I belive that you are missing the point. The resistance (or
impedance)
formula V=IR (or V=IZ), describes the describes the interaction of
resistance (impedance), voltage, and current. While correct and true
in all cases, those formulas are NOT Ohm's law, and it is wrong to
call them that. As shown in the second link I gave, Ohm's law is a
property of resistive linearity in a material. Just as the specific
gravity of a material is a property. If it conforms to Ohm's law, it
is ohmic. Otherwise it is nonohmic. Ratch

 

[Larry Hatch]

C. James Callaway wrote:

http://feynman.ee.ualberta.ca/ee401/archive_fall_2001.html#irbot

Simple using the IR Detector module you can get at Radio Shack, and a pic.
Very simple... full details.

-cjames

"Larry Hatch" <lhatch@flite.net> wrote in message
news:vgga5622m7c8c2@corp.supernews.com...

My son wants a robot and I have a remote I would like to use a couple
buttons to tell it forward, back, left, right, stop.

My thought was build a IR detector, drop a AVR mega8 (microcontroller)
in and get 0 and 5 to it from the IR signal. Have the input on the uC
learn the buttons and turn on drivers to the motors. I doubt RadioShack
has that type stuff now. Any simple IR detector ideas. I have IT
receiver LED in my box somewhere, and photo diodes as well.




I was tring to use whatI had. I tried IR LED to transister, but just

could not get anything on the emitter side. So look like I will call RS
before I drive there. I have old TVs and VCR, maybe a look there too.

I am going to use the AVR Mega8, 23 IO lines, fast, internal OSC, etc.
And cheap.

Thanks to all for the info..

 

[Rich Grise]

BRWVABell@webtv.net wrote in message news:<160-3EFE062D-7@storefull-2237.public.lawson.webtv.net>...

You guys are .. "THE BEST"!!

It was just a matter of rotating the knobs to clean them!

I am going to Radio Shack today to get the cleaner.

And here I thought that it was static buildup ...
That made me wonder .. Is it CLING or BOUNCE that you use as a static
guard in the wash? LOL

Thank You Everyone : )

Brenda

Either one - even Downy. Like this one guy said to me once, "Any ol'
anionic surfactant will do." The interesting thing is, if you mix it
with water and put it in a spray bottle, and you can antistatic your
carpets with it for about 1/10 the price of aerosol carpet anti-static
sprays.

But don't use it as contact cleaner, either.

Cheers!
Rich

 

[John Larkin]

On Sat, 19 Jul 2003 00:52:12 -0400, "Mike" <mike@risny.com> wrote:

Is a PIC the same as a Basic Stamp?

--Mike

A Basic Stamp is (usually) a PIC that includes a Basic language
interpreter. But most PIC processors are used other ways.

"PIC" refers to Microchip's family of weird, cheap, nasty little
microprocessors.

John

 

[pic]

What do you think of their prices, on averge 13 Pounds a piece.

"Neil" <fredd133@hotmail.com> wrote in message news:fehSa.53266$4c.15136@news-binary.blueyonder.co.uk...

"pic" <<> wrote in message news:bfc4uq01l2c@enews4.newsguy.com...
Hello all,
Where can I buy pic microcontrollers. The selection in maplin
is limited, are there any other sources?

Farnell have a pretty wide range, and take credit card orders from private
individuals.
hth
Neil

 

[Neil]

Where can I buy pic microcontrollers?
The selection in maplin is limited, are there any other sources?

Farnell have a pretty wide range, and take credit card orders
from private individuals.

What do you think of their prices, on average Ł13 each.

Depends which particular version you are after.

RS Components rswww.com also sell them but are probably more expensive.
(btw - have you included vat and delivery ?)

If you're buying as a business then there are loads of distributors.

Perhaps the Microchip site lists distibutors, most of which will take money
from anyone, but have different ideas about minimum order quantity.

hth
Neil

 

[John Smith]

I didn't realize it was just that simple. In my limited experience I haven't
seen any circuits arranged exactly like that.

As for "logic of the base" what I meant was, it doesn't matter if the effect
was an inverter or somehow re-arranged to not be an inverted. But as Roger
mentioned, it's always inverted.

Now I think it's time for me to read up on the finer points of current flow
through transistors.

Thank You to everyone who responded!

 

[Terry King]

Dave, That device is pretty obviously a "Opto-Triac"
of some type. I just don't personally recall one
with that large a case...

If you disconnect the 1-2 leads, does the heater turn off??
I assume not, since the LED does turn off.

So I THINK you need a "opto-triac" whose output is rated
at 240VAC or more, and which probably has an internal
infrared LED connected to 'terminals 1-2'. Motorola
makes a series like MOC3020 or something like that.
These are physically small IC type packages, but I'm
sure you can 'sky-wire' something here.

Hopefully someone here can recommend a good replacement
device.

--
Regards, Terry King ...In The Woods In Vermont
terry@fredking.us
The one who Dies With The Most Parts LOSES!! What do you need?

 

[Andre]

"Ratch" <Watchit@Comcast.net> wrote in message news:<c3bSa.82602$OZ2.15217@rwcrnsc54>...

"Mark D. Zacharias" <mzacharias@nospam.earthlink.net> wrote in message
news:LD9Sa.109299$Io.9351661@newsread2.prod.itd.earthlink.net...
To a technician, Ohm's Law is the set of mathematical operations which
predict the behavior of voltage, current, etc. After using them for so
many
years, I think it's understandable that a tech would only think of the
formulas and not the simple "mission statement" which would be the
"statement" of Ohm's Law. I'll stick with the formulas, thank you.

Mark Z.

The formulas (V=IR and variations) are correct and true, and I in no way
said they are otherwise. I only said that calling them Ohm's law is a
misnomer, because the real Ohm's law is about resistive linearity, which is
a property of a material and not a formula. I made no mission statement nor
advocated any crusade, movement, or revolution. I only made and defended a
simple statement of fact that Ohm's law is not what most people think it is.
i.e. the resistance or impedance formulas. Ratch

Yup.

BTW, LEDs are far more complex than you might think . I once had one
that flickered randomly at low current yet worked fine at 30 mA .

Was a blue RS LED, FWIW .

They behave strangely at low currents - I also had the "LED
hysteresis" effect , where it turns on at a higher current than it
turns off . This was on a damaged red LED .

"Ratch" <Watchit@Comcast.net> wrote in
news:BZmRa.80118$Ph3.9181@sccrnsc04:


"Mark D. Zacharias" <mzacharias@nospam.earthlink.net> wrote in message
news:4BmRa.5630$Mc.475640@newsread1.prod.itd.earthlink.net...
Yes, and Ohm's Law describes the interaction of resistance, voltage,
and current. Not just resistance.
I'm not an engineer, granted, but I don't require an education on
Ohm's
Law.

Mark Z.

I belive that you are missing the point. The resistance (or
impedance)
formula V=IR (or V=IZ), describes the describes the interaction of
resistance (impedance), voltage, and current. While correct and true
in all cases, those formulas are NOT Ohm's law, and it is wrong to
call them that. As shown in the second link I gave, Ohm's law is a
property of resistive linearity in a material. Just as the specific
gravity of a material is a property. If it conforms to Ohm's law, it
is ohmic. Otherwise it is nonohmic. Ratch

 

[R. Steve Walz]

Larry Hatch wrote:

Mike wrote:

Is a PIC the same as a Basic Stamp?

--Mike


Pretty much..
---------------

NO!

You can buy 16F84 chips and program them. As well, you
can look at the Atmel AVR, the Mega8 is VERY nice. The 2313 is
comparable to the 16F84, they are less money and there is a
free compiler at bastoc.com it is called RVKBASIC.

-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