Chip with simple program for Toy

On Mon, 28 Mar 2005 23:09:00 +0000, elehman1 wrote:

Sorry for my typing skills. I ment to say:

What do you do with unused pins?

elehman1@columbus.rr.com> wrote in message
news:STR1e.21517$rL3.11988@fe2.columbus.rr.com...
Should the used pins be left unconnected or should they be taken to
ground?
Click to expand...
All the jokes aside, an unused input to a logic circuit should never be
left floating. You never know what state it will take on powerup. Worse,
you never know when it's going to change.

Tie each unused input to whatever value won't change the output. For
instance, if you use a two-input NAND gate as an inverter, you can tie one
input high or to the other input. Both will work, although paralleling
inputs increases the fan-in, which may be significant. With an OR or NOR
gate, unused inputs need to be held low. Some logic families may require
a resistor instead of a direct connection to either supply rail; check
your data sheets.

Unused outputs can float.
 
On Mon, 28 Mar 2005 17:44:30 -0800, "John"
<welcomehowcome@hotmail.com> wrote:

"Eric R Snow" <etpm@whidbey.com> wrote in message
news:8d6e411i1kaavb8dncif09otiu37g4ri94@4ax.com...
On Sun, 27 Mar 2005 02:06:35 GMT, "Lord Garth" <LGarth@Tantalus.net
wrote:


"Andreas Rutz" <enemy_soldier@hotmail.com> wrote in message
news:d253mp$cu$1@news.hispeed.ch...
Michael Black wrote:

I don't know, but surplus stores used to advertise surplus phone
ringers (ie from military field phones) as useful for bringing worms
to the surface. These were hand-cranked generators, which I don't
know the output of, but if someone else does it might answer the
question.

Michael


It's around 100V AC , 20Hz for these old-stlye field telephones. Maybe
ist
is a possibility to use current limited mains voltage. Use an isolation
transformer under any circumstances and be very careful what you are
doing!
Or get such a military phone...


I wonder if the fire ant would leave if the soil were energized?


I wonder if they would just catch on fire. But as to the question of
bringing worms to the surface: How could you be so mean? Well, if you
are that cruel, wanting to shock defenseless worms until they do your
bidding and all, you'll need about 90 volts minimum. It seems AC works
best. I dunno why, but that's what worked when I was a kid. And after
you get all those worms to surface mebbe you should consider a career
in the military working at Gitmo.
ERS

WOW! You ever go fishing? These womanized "men" these days get on my fucking
nerves.

Oh John, how can you say that? You've hurt my feelings! Sob! John, my
Click to expand...
post was meant to be tongue-in-cheek. If I was really worried about
hurting worms why would I have posted the method to do it. Maybe you
should drink a little more coffee before you read the posts. Or maybe
I should stop my pathetic attempts at humor. I thought that the
deliberate misspellings would sort of be a clue. Guess I was wrong.
Not the first time.
Cheers,
Eric R Snow
 
"Steve Rush" <steverush1@SPAM_ME_NOT.cox.net> wrote in message
news:pan.2005.03.29.03.00.07.181630@SPAM_ME_NOT.cox.net...
All the jokes aside, an unused input to a logic circuit should never be
left floating. You never know what state it will take on powerup. Worse,
you never know when it's going to change.
Click to expand...
Along those same lines, what about unused microcontroller ports? Say a PIC
16F8xx. Can you just set them as outputs and ignore them?

--
Glenn Ashmore

I'm building a 45' cutter in strip/composite. Watch my progress (or lack
there of) at: http://www.rutuonline.com
Shameless Commercial Division: http://www.spade-anchor-us.com
 
On Mon, 28 Mar 2005 21:02:28 -0800, clintonb wrote:
Actually, I AM talking about soldering the lugs. I don't think I'm
applying the heat too long. But sometimes when I'm done, the pots
don't work quite right. Sometimes they cut out while turning them.
Replacing them always seems to work.

Recently, I had a pot on my guitar amp that I took out and put back in.
When I was finished, the volume wouldn't turn off and the it didn't
behave the same. So I replaced it with another pot then it worked
fine.
Click to expand...
Dirt.

Especially if you're using old, surplus, or recycled pots.

This kind of pot is notorious for intermittent connections. It isn't
soldering heat, it's just crud between the element and wiper. Get some
proper potentiometer cleaner spray, sometimes called contact cleaner,
or contol cleaner, or the like - look for something guaranteed to leave
no residue.

But just plain old ordinary dust in the air can cause this kind of
behavior in potentiometers. (I'd have said "pots", but didn't want
to open the thread to the bean cookers. ;-) )

Good Luck!
Rich
 
raul@2minclip.biz wrote:
Can I use my dc power supply to charge rechargable batteries? Not AA's
but something like a motorcycle battery.
Thanks, Raul
Click to expand...
If it has a settable or appropriate current limit (say, an ampere or
so) to protect a defective or really run down battery from
overheating, and a voltage regulation setting that is also appropriate
(say, 6.8 or 13.6 volts), to limit the charge to no more than full,
then sure.

--
John Popelish
 
On 28 Mar 2005 21:02:28 -0800, clintonb@fflax.net wrote:


Actually, I AM talking about soldering the lugs. I don't think I'm
applying the heat too long. But sometimes when I'm done, the pots
don't work quite right. Sometimes they cut out while turning them.
Replacing them always seems to work.

Recently, I had a pot on my guitar amp that I took out and put back in.
When I was finished, the volume wouldn't turn off and the it didn't
behave the same. So I replaced it with another pot then it worked
fine.
Click to expand...
I wonder if these might be conductive plastic pots?
You might want to pry open one of the damaged ones
and see what it looks like under the hood. If this
doesn't tell you at a glance what is happening, you
could then experiment by soldering the connector
and watching what happens. If it's not actually
melting the polymer, it might be causing it to exude
something non-conductive to the surface.

Best regards,


Bob Masta
dqatechATdaqartaDOTcom

D A Q A R T A
Data AcQuisition And Real-Time Analysis
www.daqarta.com
 
"Glenn Ashmore" wrote ...
Along those same lines, what about unused microcontroller
ports? Say a PIC16F8xx. Can you just set them as outputs
and ignore them?
Click to expand...
That would certainly seem like the logical thing to do.
No pun intended.
 
stu@aaronj.com wrote:

These paragraphs are from an article about a homebuilt hybrid car in
Mother Earth News.

"Any project fresh off the drawing board has its share of problems, and
the Opel hybrid was no exception. When David pressed the accelerator
for the first time, he got a 300-amp surge which melted his relays. So
he searched his graduate texts for the answer ... and finally found it
in-of all places-an old high school physics book: A pulser was
necessary to "chop" the current flow and prevent a heavy initial draw
to the drive motor.

As Dave explains it, "The motor will always have full voltage and full
current, but the pulser makes it 'think' the voltage and amperage are
cut down to about 1/4 of what's actually available. With this
gadget-which is simply a combination of a reworked car generator and an
old fan motor-I can keep the draw within limits and effectively control
the car's acceleration . . . without sacrificing the maximum current or
voltage that's necessary for high-speed driving. I could have achieved
the same results with a commercially available FCR control ... but one
of those units would have cut my power slightly, and cost in the
neighborhood of $800! I can build my own device for about $25, and I
can fix it myself if it breaks!"


Boyntonstu

Pulse Width Modulation?
Click to expand...
 
stu@aaronj.com wrote:

Hey guys, you don't get the question.

I know all about electronic PWM controllers like Curtis and Alltrax.
The article is a PULSER speed controller that is made up of electrical
and not electronic components; namely a generator and a fan motor.

Let me rephrase the question:

How can you control the speed of a dc motor using a generator and a fan
motor?


Boyntonstu

Hmm.
Click to expand...
sounds like a backyard hack job to me.
lets see.
Generator is attached to the shaft so it generates
more power as the RPM's increase, this in turn drives
the Fan Motor or Helps in increasing the FAN motor
speed.
then the blades on the fan simply hit a mechanical weighted
switched that will pulse the contacts and at some point when
going fast enough stay closed..
sounds like hack to me.
or it could be using some kind of optical switch via the fan
blades that engages mercury relay.
who knows..
i guess the centrifugal would take over at some point and
keep the contacts closed.
 
mowhoong wrote:
We knew that all the Aluminium Electrolytic capacitor having shelf
life of 5 year
according to the mfe standard.( Due to crystaline in the material). Is
that mean any electronic product if you do not use more than 5 years
will not fuction properly ? Hence why can't we use non- electrolytic
capacitor to substitute ?
Can any person know the reason ? Thanks.
Click to expand...
Properly derated, good quality electrolytic capacitors, (temperature,
temperature rise, voltage) can last a lot longer than 5 years. Poor
quality caps that are running at several of their maximum ratings can
have a very short life.
One of the wear out mechanisms is loss of electrolyte through the seal
material. I do not know what you are referring to by, "Due to
crystaline in the material".

--
John Popelish
 
On 28 Mar 2005 19:12:56 -0800, "eeh" <eehobbyist@yahoo.com.hk> wrote:

Hi,

I am going to design a DSP system which needs to interface with SDRAM.
The system clock is running at 200MHz. I have calculated the wavelength
to be 15mm.
Click to expand...
1500 mm in free air, maybe 1m on a PC board.

The question is whether do I need to regard each data line and address
line as transmission line and do matching for each line?
Click to expand...
It certainly doesn't hurt. But the complexities are such that a
newsgroup is not the place to resolve them.

John
 
mowhoong (mowhoong@hotmail.com) writes:
We knew that all the Aluminium Electrolytic capacitor having shelf
life of 5 year
according to the mfe standard.( Due to crystaline in the material). Is
that mean any electronic product if you do not use more than 5 years
will not fuction properly ? Hence why can't we use non- electrolytic
capacitor to substitute ?
Can any person know the reason ? Thanks.
Click to expand...
You misread the situation. People don't use electrolytics becasue
of some special characteristic, they use them because that's the only
feasible way to get larger capacitances. Find a non-electrolytic with
a value of 1uF or more, and it gets rather large. But switch to electrolytic
and they become much smaller. It's the construction of the electrolytic
that allows the higher capacitance within a reasonable package.

So you will find that virtually all the capacitors over 1uF or
so are electrolytic. The exceptions are when there is a very specific
need for something else, such as specific value (electrolytics don't
come in tight tolerances). There is little other reason to justify
the size and cost of non-electrolytics in those larger values.

And once you have that path, then people simply live with any drying
out of electrolytics.

Michael
 
I read in alt.binaries.schematics.electronic that Richard Crowley
<rcrowley7@xprt.net> wrote (in <114iq4d6q9vlv48@corp.supernews.com>)
about 'Question About IC Chips', on Tue, 29 Mar 2005:
"Glenn Ashmore" wrote ...
Along those same lines, what about unused microcontroller ports? Say
a PIC16F8xx. Can you just set them as outputs and ignore them?

That would certainly seem like the logical thing to do.
No pun intended.
Click to expand...
Oh, go on, intend away! No-one was ever punished for a really good pun.

You know what is paved with good intentions? (;-)
--
Regards, John Woodgate, OOO - Own Opinions Only.
There are two sides to every question, except
'What is a Moebius strip?'
http://www.jmwa.demon.co.uk Also see http://www.isce.org.uk
 
SklettTheNewb escribió:

I would like to calculate how long an LED will stay lit given a
specific power source. I need to know what the smallest battery I can
use in a project and still get n hours of operation.
Click to expand...
Batterycapacity(mAh)/Led courrent(mA)=hours of operation
 
On 29 Mar 2005 08:50:53 -0800, "rollajarhead"
<rolla_jarhead@yahoo.com> wrote:

John Fields wrote:
On 28 Mar 2005 13:29:53 -0800, "rollajarhead"

---
If you're going to make some money from this project and you need
help
to complete it and you want me to help you, I'll be more than happy
to
email you schematics, bills of material, etc, (for a fee, of course)
but if you're looking for free help and you want to keep the
discussion in this group, (seb) it would certainly be a good idea for
you to post the schematic you mentioned, in its entirety, to abse.
That way we can all have a look at what it is you think you want to
do
and comment on it.

--
John Fields

No I will not be making any money on this project, it is for my
personal use.

This may not be the forum to ask this in but if I post the full
schematic do I need to get permission from the manufacturer? Would you
want the full schematic or just the items we have been discussing?

I am new to both electronics (less then 7 or 8 months) and the Usenet;
this is only the second topic I have posted to. I don't mean to
offend.
Click to expand...
---
You weren't being offensive, I was being grouchy. Sorry about that.
I don't know what the deal would be if you emailed the schematic to
the NG, but if you email me a copy that would be considered "fair
use" and wouldn't be an infringement. You may as well go ahead and
email me the whole thing just in case something comes up later.

Also, I'll need to know how much current the camera inputs need to
draw when they're being exercised.


--
John Fields
 
In article <1112119092.206028.13690@z14g2000cwz.googlegroups.com>,
SklettTheNewb <SteveKlett@gmail.com> wrote:
great, thank you for the response.
So with that calculation and a 1.5v, 140mAh battery and a 1.5v, 20mA
LED, I would be looking at roughly 70 hours of constant operation.
Click to expand...
Missed a decimal point. 140mAh/20mA = 7 Hrs, not 70.

The other problem is that the LED requires a specific forward voltage.
The battery's voltage will most likely drop during its use. At some point
before the 7 hours, the LED will go out.

Finally you may not have enough forward voltage even at 1.5V

BAJ
 
<bolwarra5@hotmail.com> wrote in message
news:1112124842.376126.81250@f14g2000cwb.googlegroups.com...
Well , I'll put this crazy problem forward and see what comes back. The
project is to have a candle (modified or 'gimmicked' I guess) under a
cup which is face down on a table. When the cup if lifted up (hence
revealing the candle) the candle is already lit. The solution I have
come up with is to have some type of light sensor that connects to a
glow plug (model plane engine part) that lights some lighter fluid and
lights the wick. So therefore when the cup is lifted , it activates the
glow plug which lights some fluid which lights the wick.
Any better ideas?
Click to expand...
Better try the glow plug ignition early. I seem to
recall glow plugs just sizzling fuel until some extra
temperature is created by compression in the
engine cylinder. Maybe a spark discharge would
be more reliable and energy efficient.

I know its a strange project but I guess so is life.
Click to expand...
Sounds like fun. Fire is ... lots of fun!

--
--Larry Brasfield
email: donotspam_larry_brasfield@hotmail.com
Above views may belong only to me.
 
On 29 Mar 2005 11:34:02 -0800, bolwarra5@hotmail.com wrote:

Well , I'll put this crazy problem forward and see what comes back. The
project is to have a candle (modified or 'gimmicked' I guess) under a
cup which is face down on a table. When the cup if lifted up (hence
revealing the candle) the candle is already lit. The solution I have
come up with is to have some type of light sensor that connects to a
glow plug (model plane engine part) that lights some lighter fluid and
lights the wick. So therefore when the cup is lifted , it activates the
glow plug which lights some fluid which lights the wick.
Any better ideas?
I know its a strange project but I guess so is life.
Click to expand...
Such complex and potentialy dangerous solutions to a simple problem.
Take a match and slice into the head with a sharp razor blade. Slip
a piece of fine wire into the slit and wrap it around the head.
Solder some larger gauge wires to the fine wires so the joint is
below the head. Secure the wires to the paper match stick with
masking tape.

The larger wires won't fuse when you apply a voltage, but the fine
wire will light the match. Fudge and practice until you can just
tilt the cup enough to let in light and get the flame near the wick
- if the whole contraption is inside the cup. You could hide it
behind the candle. Don't use a flammable cup. Placing the cup on the
table will extinguish the match, if it's in the cup. If you want
your audience to see that the cup is empty and there's nothing
behind the candle, make your own candle around everything - battery,
sensor, ignitor.

You should be able to set the match off with 1 or 2 batteries - like
the old 000 steel wool firestarter trick.
--
Best Regards,
Mike
 
On Tue, 29 Mar 2005 18:31:05 +0100, John Woodgate wrote:

I read in alt.binaries.schematics.electronic that Richard Crowley
rcrowley7@xprt.net> wrote (in <114iq4d6q9vlv48@corp.supernews.com>)
about 'Question About IC Chips', on Tue, 29 Mar 2005:
"Glenn Ashmore" wrote ...
Along those same lines, what about unused microcontroller ports? Say
a PIC16F8xx. Can you just set them as outputs and ignore them?

That would certainly seem like the logical thing to do.
No pun intended.

Oh, go on, intend away! No-one was ever punished for a really good pun.

You know what is paved with good intentions? (;-)
Click to expand...
Do you know where the apathetic Buddhists worship?

So Wat.

;-)
 
On Tue, 29 Mar 2005 12:42:19 -0800, SklettTheNewb wrote:

maybe a section of cocktail straw of mini water ballon with nitro hobby
fuel, wrap it with small guage wire and lay it next to the wick...
that would work...
Click to expand...
Or he could go to the hobby store and buy some squibs.

Cheers!
Rich
 
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