Chip with simple program for Toy

[Gnekker]

"Wong" <tatto0_2000@yahoo.com> wrote in message
news:509bfe22.0307310005.4cc3f81c@posting.google.com...

Hi,
I need to measure some start-up state of the IOs. As indicated,
those IOs are tri-state IOs. So I am wonder whether I can measure the
Hi-Z from oscilloscope ?

Thanks a lot.

regards,
Wong

Fairly easy, connect some signal source with suitable range (I assume 0 -
5V) and add some resistance of say 47 Kohms or so (You don't want to burn
the chip, do you?). If the state on the output is low, then it is - low, if
it is high, it is - high, if it is the same as signal source, then it is
Hi-Z.

 

[Ban]

Wong wrote:

Hi,
I need to measure some start-up state of the IOs. As indicated,
those IOs are tri-state IOs. So I am wonder whether I can measure the
Hi-Z from oscilloscope ?

Thanks a lot.

regards,
Wong

Take a 100k resistor and connect a slow square wave or sinus
generator(<1kHz, swing from 0V to Vcc) through it to the pin. when the scope
shows the full symmetrical swing it is high impedance or input. When it is
closer to 1 rail but still moves a bit, it has pull-up resp. -down resistor
activated, if it stays high or low with *very* little movement, it's an
active output.

This way there is no damage to the IO possible. Of course the static
electricity handling rules should be observed.

ciao Ban

 

[Mario Trams]

Wong wrote:

Hi,
I need to measure some start-up state of the IOs. As indicated,
those IOs are tri-state IOs. So I am wonder whether I can measure the
Hi-Z from oscilloscope ?

One idea might be to attach once a pull-up (say 50kOhm) and once a
pull-down. If you get a high-level with the pull-up and a low-level
with the pull-down, your output is Hi-Z.

Measuring Hi-Z alone (i.e. with an oscilloscope) is not possible.

Regards,
Mario

 

[Robert Lacoste]

Or connect it, still through 100K, to Vcc/2... Less bullet proof than Ban's
solution, but easier...

Robert Lacoste - ALCIOM : The mixed signals experts
http://www.alciom.com

"Ban" <bansuri@web.de> a écrit dans le message de news:
bo4Wa.3573$cl3.123625@news2.tin.it...

Wong wrote:
Hi,
I need to measure some start-up state of the IOs. As indicated,
those IOs are tri-state IOs. So I am wonder whether I can measure the
Hi-Z from oscilloscope ?

Thanks a lot.

regards,
Wong

Take a 100k resistor and connect a slow square wave or sinus
generator(<1kHz, swing from 0V to Vcc) through it to the pin. when the
scope
shows the full symmetrical swing it is high impedance or input. When it is
closer to 1 rail but still moves a bit, it has pull-up resp. -down
resistor
activated, if it stays high or low with *very* little movement, it's an
active output.

This way there is no damage to the IO possible. Of course the static
electricity handling rules should be observed.

ciao Ban

 

[Joseph Legris]

Wong wrote:

Hi,
I need to measure some start-up state of the IOs. As indicated,
those IOs are tri-state IOs. So I am wonder whether I can measure the
Hi-Z from oscilloscope ?

Thanks a lot.

regards,
Wong

Easy, just put your finger on the probe. You'll see 50 or 60 Hz and
other garbage on the Hi-Z points. Don't wear synthetics and discharge
your self to ground before doing this.

When I was a kid I couldn't afford anything better than a multimeter, so
I detected HF oscillations using the DC voltage range and a capacitively
coupled diode detector. With a bit of practice you can even get an idea
of the wave shape.

--
Joe Legris

 

[Jim Thompson]

On Thu, 31 Jul 2003 02:20:30 +0000 (UTC), nbrbkk@doit.wisc.edu wrote:

Hidden cam pics of my hot neighbor tanning nude, download them.
lbwgunderniyepowqmjpjeckgrfezudxkwdfxlnjn

Anybody at U of W that can seek this twerp out and adjust his
attitude? Maybe stuff his head up a cow's ass ?

...Jim Thompson
--
| James E.Thompson, P.E. | mens |
| Analog Innovations, Inc. | et |
| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
| Phoenix, Arizona Voice480)460-2350 | |
| Jim-T@analog_innovations.com Fax480)460-2142 | Brass Rat |
| http://www.analog-innovations.com | 1962 |

For proper E-mail replies SWAP "-" and "_"

Get Lolita Out of Debt... Add Three Inches to Your Mortgage!

 

[Robert Lacoste]

Easy, just put your finger on the probe. You'll see 50 or 60 Hz and
other garbage on the Hi-Z points. Don't wear synthetics and discharge
your self to ground before doing this.

Variant : Connect the pin to 110V (or 220V depending on your country). If
there is some smoke then the pin was not really Hi-Z. JUST JOKING OF COURSE,
PLEASE DON'T TRY IT...

Friendly,
Robert

 

[Tom Biasi]

"Jim Thompson" <Jim-T@analog_innovations.com> wrote in message
newss9iiv4sule035mm2jis8q2i2cr3gfp6nd@4ax.com...

On Thu, 31 Jul 2003 02:20:30 +0000 (UTC), nbrbkk@doit.wisc.edu wrote:

Hidden cam pics of my hot neighbor tanning nude, download them.
lbwgunderniyepowqmjpjeckgrfezudxkwdfxlnjn

Anybody at U of W that can seek this twerp out and adjust his
attitude? Maybe stuff his head up a cow's ass ?

...Jim Thompson

Not a very nice thing to do Jim;
to a cow.

 

[the Wiz]

James W <change-to-jw22-at-trlp-dot-com@trlp.com> wrote:

I'm need to build a circuit that will allow me to control which of
several deep cycle batteries in powering a circuit that can draw as much
as 20 amps at 12-14vdc.

I could use relays.. but I hate to waste battery power to hold the relays..

The circuit needs to allow dc current in either direction ( normally the
batteries are supplying all the power, but on occasion, I do have to
recharge batteries, and would like to use the same 'switch' to select
which battery is being charged.

Would a rippin big MOSFET be reasonable for something like this? Other
ideas?

Latching relays - one application of power turns it on, another turns it off -
no holding current, minimal voltage loss, high current capacity.

More about me: http://thelabwiz.home.mindspring.com/
VB3 source code: http://thelabwiz.home.mindspring.com/vbsource.html
VB6 source code: http://thelabwiz.home.mindspring.com/vb6source.html
VB6 - MySQL how to: http://thelabwiz.home.mindspring.com/mysql.html
My newest language - NSBasic for the Palm PDA: http://thelabwiz.home.mindspring.com/nsbsource.html
Drivers for Pablo graphics tablet and JamCam cameras: http://home.earthlink.net/~mwbt/
johnecarter atat mindspring dotdot com. Fix the obvious to reply by email.

 

[AC/DCdude17]

X-No-Archive: Yes

James W wrote:

I'm need to build a circuit that will allow me to control which of
several deep cycle batteries in powering a circuit that can draw as much
as 20 amps at 12-14vdc.

I could use relays.. but I hate to waste battery power to hold the relays..

The circuit needs to allow dc current in either direction ( normally the
batteries are supplying all the power, but on occasion, I do have to
recharge batteries, and would like to use the same 'switch' to select
which battery is being charged.

Would a rippin big MOSFET be reasonable for something like this? Other
ideas?

High current relay is your best bet as the other guy mentioned. It's just like
a toggle switch that is electrically triggered. I'm not sure where you'll find
it however.

If you can't find one, go with a relay. The loss in coil is much lesser than
junction loss in MOSFETs.

You need to use a pair of MOSFETs to allow bidirectional use. Since MOSFETs
are conductive in opposite direction, each MOSFET must have an external diode
to limit current flow to proper direction so that when you want to switch off,
current doesn't go through other MOSFET.

 

[R.Legg]

Consider a pipe a mile long, 100" diameter at one end, tapering off to
1" at the other. Would water flow as well in this pipe as in one that
was uniformly 57 inches (which would have 33% of the inlet area)?



I posted the exact equation, um, somewhere nearby. For smallish inner
radius r, thermal resistance goes up as 1/r.

resistance increases proportionally to 1 / (r^2) - the increase is
related to change of the surface area of the concentric sphere at the
radius being examined. Surface are is 4 . pi . r^2.


The equation was

R = rho(1/r2 - 1/r1)/4*pi

You were correct to question the 33% figure. I'm sort of dissapointed

that you didn't take the time to do a bit of figuring and suggest a
better one.

The problem with these numbers was that they looked at relative
conductivity - not the reciprocal impedance.

Looking at impedance, internal source radii below 33% of the external
radius will actually dominate the impedance. There is more than a 50%
increase for every 10% (of the external radius) that is subtracted
from the internal radius.

Looking at the increasing effect of the differing source radii, and
using a 10% difference as the base-line, the incremental
cross-sectional area effect on the ball source path is:

shell deltaZ accum unpotted potted effect
..9 - 1 1 1 1 1
..8 - .9 1.23 2.23 1.10 1.12 x.98
..7 - .8 1.59 3.82 1.56 1.28 x.82
..6 - .7 2.14 5.96 2.04 1.50 x.75
..5 - .6 3.82 9.78 2.78 1.88 x.68
..4 - .5 4.64 14.42 4.0 2.34 x.58
..3 - .4 7.91 22.3 6.25 3.23 x.52
..2 - .3 16.45 38.8 11.1 4.78 x.43
..1 - .2 34.1 72.9 25.0 8.19 x.33

The relative impedance of the epoxy layers increase as they approach
the center of the structure. (deltaZ)

The accumulated effect of the epoxy thickness can be
summarized.(accum)

An unpotted single-temperature source of constant power experiences a
surface temperature increase as it's radius and surface area are
reduced. (unpotted)

The thermal conductivity of epoxy will be somewhere between 10x to 50x
that of air (0.2 to 1.0 W/mK vs .025W/mK). This forces a lower
relative increase in the temperature rise of the lowest layer,
dependant on depth. (potted)

The relationship between free air source and potted source is the
ratio between the potted and unpotted change. (effect)

These numbers suggest that with a commodity potting material
(conductivity 0.2 W/mK), the source surface rise will be less than
double the potted assy surface rise, providing that it is distributed
evenly to a radius of at least 30% of the potted sphere's outer
surface dimension.

I may be wrong. Perhaps you have a different perspective to offer,
with some ball-park numbers. Please don't use plumbing analogies,
these only go so far before you have to do things like relate delta T
to water velocity - if you have to, use current flow in conductors.

RL

 

[Rich Mechaber]

w/r/t charging, you may need to use a make before you break connection,
depending on your charging source. Alternator diodes can blow if you
don't have a load for them.

Rich Mechaber

James W wrote:

I'm need to build a circuit that will allow me to control which of
several deep cycle batteries in powering a circuit that can draw as much
as 20 amps at 12-14vdc.

I could use relays.. but I hate to waste battery power to hold the relays..

The circuit needs to allow dc current in either direction ( normally the
batteries are supplying all the power, but on occasion, I do have to
recharge batteries, and would like to use the same 'switch' to select
which battery is being charged.

Would a rippin big MOSFET be reasonable for something like this? Other
ideas?

 

[David Harmon]

On Thu, 31 Jul 2003 11:04:09 +0200 in sci.electronics.basics,
"Robert Lacoste" <rlacoste@alciom.com> wrote:

Or connect it, still through 100K, to Vcc/2... Less bullet proof than Ban's
solution, but easier...

Please explain to me why this is not a really bad idea... My
understanding is that holding CMOS inputs at V/2 can cause large
power dissipation in the input circuits and should be avoided?

 

[Michael A. Terrell]

Nir Goren wrote:

[Image]

This is not a binaries newsgroup.

You can post it to news:alt.binaries.schematics.electronic by attaching
it as a GIF, JPEG, or other common image file. Then, post a message
here giving the name of the post. If you try to post a binary file
here, most people will never see it.
--


Michael A. Terrell
Central Florida

 

[Genejocky]

It doesn't sound like anyone is doing anything too nice.

I've benn meaning to ask before having wondered for some time...
... what does ">lbwgunderniyepowqmjpjeckgrfezudxkwdfxlnjn" mean??
Soory if it's a ignorant question :-(
Gene

"Tom Biasi" <Tom@Home.net> wrote in message news:<b1dWa.5864$Wd5.1427376@news4.srv.hcvlny.cv.net>...

"Jim Thompson" <Jim-T@analog_innovations.com> wrote in message
newss9iiv4sule035mm2jis8q2i2cr3gfp6nd@4ax.com...
On Thu, 31 Jul 2003 02:20:30 +0000 (UTC), nbrbkk@doit.wisc.edu wrote:

Hidden cam pics of my hot neighbor tanning nude, download them.
lbwgunderniyepowqmjpjeckgrfezudxkwdfxlnjn

Anybody at U of W that can seek this twerp out and adjust his
attitude? Maybe stuff his head up a cow's ass ?

...Jim Thompson

Not a very nice thing to do Jim;
to a cow.

 

[Lord Garth]

"Genejocky" <genejocky2000@yahoo.com> wrote in message
news:5b42948.0307312254.4ea6f078@posting.google.com...

Hello All,

I am currently running a printer via usb cable.
I'd like to opperate the printer in another room from the pc.
The total length of the cable should still fall within the maximum
length allowed for the usb specification.
The plan is to create 2 cables by cutting the current usb-A to usb-B
cable in half.
A RJ45 connector is to be attached to each "cut end" to allow the pc
to connect to the usb cable- to the rj45 connector- to the cat5e cable
behind a wall plate- to the other end of the cat5e cable/wall plate in
the other room- to a RJ45 connector- to the 2nd half of the cut
printer cable- to the printer.

I'm a little unsure as to how to wire the two RJ45 connectors to the
cut USB cable.

Would anyone out there be able to help?

Thank you for your help

Gene

Since this is a totally unique extension cable, feel free to build anything
you desire. I suggest you use the 4 contacts not used by network interface
cards. Specifically, I'd use pins 4, 5, 7 & 8. Be sure you use a twisted
pair for the USB data + and data - signals.

 

[Ken]

On 31 Jul 2003 23:54:14 -0700, genejocky2000@yahoo.com (Genejocky)
wrote:

I am currently running a printer via usb cable.
I'd like to opperate the printer in another room from the pc.
The total length of the cable should still fall within the maximum
length allowed for the usb specification.
The plan is to create 2 cables by cutting the current usb-A to usb-B
cable in half.
A RJ45 connector is to be attached to each "cut end" to allow the pc
to connect to the usb cable- to the rj45 connector- to the cat5e cable
behind a wall plate- to the other end of the cat5e cable/wall plate in
the other room- to a RJ45 connector- to the 2nd half of the cut
printer cable- to the printer.

Bad idea.

--

+ Ken +

 

[Ian Buckner]

"David Harmon" <source@netcom.com> wrote in message
news:3f4dcbcb.189975357@news.west.earthlink.net...

On Thu, 31 Jul 2003 11:04:09 +0200 in sci.electronics.basics,
"Robert Lacoste" <rlacoste@alciom.com> wrote:

Or connect it, still through 100K, to Vcc/2... Less bullet proof
than Ban's
solution, but easier...

Please explain to me why this is not a really bad idea... My
understanding is that holding CMOS inputs at V/2 can cause large
power dissipation in the input circuits and should be avoided?

If the pin is tristated (Hi-Z), it doesn't matter - by definition no
current will flow.
If the pin is _not_ tristated, the 100k is high enough that no
significant current will flow, the pin driver will pull the pin
either low or high.

Regards
Ian

 

[Dana Raymond, a minor God]

Why a joystick?
If you wish to have the computer measure and possibly record the wheel
speed, and the wheel already has a pule sensor, then get a CTC card from
computerboards inc or metrabyte or use software to count pulses from the
parralel or serial port to do the job.

If a joystick POT is a requirement then some custom electronics could be
designed. Perhaps an opamp buffer/integrator that converts the pulse
frequency into a voltage that would replace the POT wiper voltage.

Hope this helps.
Dana Raymond

"Adam Brown" <adam@freestream.com.au> wrote in message
news:3f29fd55$0$95049$c30e37c6@lon-reader.news.telstra.net...

Hi,

My electrical knowledge is minimal. I'd like to convert the speed of a
wind
trainer into the forward input of a computer joystick. I can use a cheap
cycle computer which generates small pulses of current each time the wheel
rotates. Is there a simple way to use these pulses to control the
resistance in the joystick that controls forwards/backwards.

Some quick research suggests another alternative might be to use a dynamo
which might in turn control a JFET which could replace the joystick
potentiameter.

The cycle computer options is the most elegant. Is there a circuit that
can
be built to smooth the pulses to provide a constant voltage which can be
applied to the JFET?

Is there an altogether superior solution?

Any help appreciated,

Adam

 

[h]

"Genejocky" <genejocky2000@yahoo.com> wrote in message
news:5b42948.0307312307.162f058b@posting.google.com...

It doesn't sound like anyone is doing anything too nice.

I've benn meaning to ask before having wondered for some time...
.. what does ">lbwgunderniyepowqmjpjeckgrfezudxkwdfxlnjn" mean??
Soory if it's a ignorant question :-(
Gene

AIUI mass-mailer programs will optionally add a random string of crap to
each spam sent in order to bypass spam-filters that rely on hashing. Stops
the big ISPs from being able to identify and remove spam easily.

h