Chip with simple program for Toy

[Larry Brasfield]

"John Douglas" <jdamja@sbcglobal.net> wrote in message
news:1116945472.214926.252050@g44g2000cwa.googlegroups.com...

I had thought lead-free solder was considered safe.

Many do. You could overdose on it, though. If
enough is stuffed down someone's gullet, they die.

I was prepared to let a 12 year old begin soldering (under supervision)
until I saw a warning on the back of the package stating that 'this
product contains a known carinogen to the state of Calif' (not exact
quote). Its standard stock lead-free solder from Radio Shack having
96% tin, 4% silver. (Where's the carcinogen in that?)

Do you live in California? If so, and you take all the
locals' fears seriously, you will have to deal with that
issue first. Otherwise, please be aware that the state
is known for going so far overboard with warning
labels that many people ignore them, rationally.

I am reluctant to let a child use this solder.
Does a safe solder exist?

You could eat solder once in awhile without harm.
It is a metal and passes thru the GI tract. A small
amount can be absorbed, so don't make it a habit.

I would be more concerned about breathing the
smoke from the burning resin, but for occasional
exposures even that is a far-fetched worry.

Thanks,

Welcome.

--
--Larry Brasfield
email: donotspam_larry_brasfield@hotmail.com
Above views may belong only to me.

 

[w_tom]

Temporarily disconnect computer and ground cable. Measure
AC current from audio ground to that new safety ground wire.
Current should be on the order of less than 1 milliamp.
Unlike the experiment with safety ground wire, this test
actually reports something useful.

Of course that grounding cable will eliminate voltage. Wire
eliminating voltage tells us nothing useful. But is that
voltage created by a leakage that is too large or by a leakage
that is acceptable? You still have not answered a question
that determines whether a threat to computer, et al exists.

If your meter does not have an AC amperage option, then
connect audio ground to safety ground via a 10K ohm resistor.
If the leakage is 150 microamps, then AC voltage across that
resistor will be 1.5 volts. If the voltage is less, then the
leakage (and need for safety ground wire) is irrelevant. If
voltage across resistors is more, than your TV may be a threat
to computer and human life.

If leakage is less than 150 uamps, then even a wire about
the size of a human hair would have been sufficient to ground
out the leakage.

Again, more informative to know what that leakage is rather
than say when it does exist. And what you will learn by
actually measuring that leakage applies to human (and
transistor) safety with all other household appliances.

siliconmike wrote:

Here's what I did: Connected TV Signal earth to safety earth directly
by a thick cable (16 SWG x 10) and then connected the PC to the TV. The
tester stopped showing any presence of voltage on the TV signal earth,
and the reception is ok. PC is ok.

 

[Peter Bennett]

On 23 May 2005 11:19:29 -0700, "Jack// ani" <nospam4u_jack@yahoo.com>
wrote:

Can I use 12V, 2amp centre tapped transformer in place of a 24V/2amp. I
will not use the tapped wire, so I'll get 24volts across its two
ends.

TIA

The "advertised" secondary voltage of a transformer is normally the
full voltage developed across its secondary, ignoring any taps, so you
will only get 12 volts from the 12 volt transformer.



--
Peter Bennett VE7CEI
email: peterbb4 (at) interchange.ubc.ca
GPS and NMEA info and programs: http://vancouver-webpages.com/peter/index.html
Newsgroup new user info: http://vancouver-webpages.com/nnq

 

[John Bokma]

John Douglas wrote:

I had thought lead-free solder was considered safe.

I was prepared to let a 12 year old begin soldering (under supervision)
until I saw a warning on the back of the package stating that 'this
product contains a known carinogen to the state of Calif' (not exact
quote). Its standard stock lead-free solder from Radio Shack having
96% tin, 4% silver. (Where's the carcinogen in that?)

I am reluctant to let a child use this solder.
Does a safe solder exist?

Use a small fan that blows away the "smoke" coming from the solder.

--
John MexIT: http://johnbokma.com/mexit/
personal page: http://johnbokma.com/
Experienced programmer available: http://castleamber.com/
Happy Customers: http://castleamber.com/testimonials.html

 

[John Popelish]

davidd31415 wrote:

Hi,

I am trying to troubleshoot a problem with an electro-dynamic shaker.
There is a coaxial output from a computer to an amplifier and outputs
from the amplifier to the shaker. I am sending a 15-150Hz 0-1V signal
to the shaker.

There was a "ground loop isolator" between the computer and the amp
(coax converted to rca, then back to coax), which had been used to
remove 60Hz line noise in the past. I know 60Hz is the AC line
frequency but have not yet understood why this particular frequency
manages to cause interference through ground loops so often; an
explanation of that would be great here as well.

Line powered equipment often leaks significant current into ground
through either resistive paths or capacitive ones. This current
alters the local potential of ground at line frequency. If you
amplify a voltage compared to local ground, and it was generated with
respect to a different local ground potential, the difference between
the two local ground voltages gets added to the signal.

What I am ultimately hoping to understand is what might be going on
with the signal:

The shaker is intermittently knocking and does not seem to be working
properly (with THIS amp only). If the ground loop isolator is hooked
up and I touch the shielding around the connectors with my hand, the
knocking goes away (otherwise the ground loop isolator makes the
knocking occur on a regular basis). I'm curious how my touching the
connector could have anything to do with this? I would initially guess
ground it has something to do with me being grounded, but to such a low
voltage does my being grounded (through shoes) make a difference to the
signal?

There is probably something in the vicinity that is radiating strong
electric fields that the cable shield is picking up as capacitive
current (probably where multiple cables run parallel). Your body adds
a lumped capacitive load to that shield when you touch it. How is the
cable shield on each side of the ground isolator grounded?

The knocking occurs intermittently when the ground loop isolator is not
connected. I've hooked a Y up to the output of the computer and
watched the signal with an oscilloscope (no ground loop isolator) and
have not noticed anything strange there, but when the scope is hooked
up and the input to the scope is disconnected (but the coax remains
connected to the Y), the shaker starts knocking more often than in any
other situation. I've also noticed that if I use the other (red) set
of rca leads on the ground loop isolator (rather than the white), there
is no knocking.

I'm thinking there may be something wrong with the ground loop isolator
since only one set of its leads causes regular knocking, but seeing as
the knocking occurs even without it and my touching it effects it, I've
though perhaps electromagnetic waves or something else may be involved
here as well.

Any input would be appreciated! Thanks,

Dave

 

[Rich Grise]

On Tue, 24 May 2005 07:37:52 -0700, John Douglas wrote:

I had thought lead-free solder was considered safe.

I was prepared to let a 12 year old begin soldering (under supervision)
until I saw a warning on the back of the package stating that 'this
product contains a known carinogen to the state of Calif' (not exact
quote). Its standard stock lead-free solder from Radio Shack having
96% tin, 4% silver. (Where's the carcinogen in that?)

I am reluctant to let a child use this solder.
Does a safe solder exist?

Don't worry about it. Since the flakes and nuts took over CA, _everything_
is a "known carciongen". The "carcinogen" is probably in the flux fumes,
and you'd have to concentrate them and breathe nothing else for 75 years,
at which point you'd probably be dead of something else anyway.

Cheers!
Rich

 

[Silver Surfer]

If you go to the Kester Web site and check their MSDS section for a
particular solder product you will find the specific carcinogen hazards
detailed there.

"Rich Grise" <richgrise@example.net> wrote in message
newsan.2005.05.24.20.31.51.341679@example.net...

On Tue, 24 May 2005 07:37:52 -0700, John Douglas wrote:

I had thought lead-free solder was considered safe.

I was prepared to let a 12 year old begin soldering (under supervision)
until I saw a warning on the back of the package stating that 'this
product contains a known carinogen to the state of Calif' (not exact
quote). Its standard stock lead-free solder from Radio Shack having
96% tin, 4% silver. (Where's the carcinogen in that?)

I am reluctant to let a child use this solder.
Does a safe solder exist?

Don't worry about it. Since the flakes and nuts took over CA, _everything_
is a "known carciongen". The "carcinogen" is probably in the flux fumes,
and you'd have to concentrate them and breathe nothing else for 75 years,
at which point you'd probably be dead of something else anyway.

Cheers!
Rich

 

[Dwayne]

"BobG" <bobgardner@aol.com> wrote in message
news:1116883306.903895.286690@z14g2000cwz.googlegroups.com...

The alternator has 3 humps per alternator rev (its 3 phase), and if you
measure the diam of the alternator pulleys, you can get the crank rps
from the pd of the alternator pulses (cap couple and use a schmidt
trigger)

In theory yes, but if the belt slips then it would mess up the system.

Dwayne

 

[Dwayne]

"Dwayne" <fake@email.com> wrote in message
news:xSNke.1472853$6l.772158@pd7tw2no...

"BobG" <bobgardner@aol.com> wrote in message
news:1116883306.903895.286690@z14g2000cwz.googlegroups.com...
The alternator has 3 humps per alternator rev (its 3 phase), and if you
measure the diam of the alternator pulleys, you can get the crank rps
from the pd of the alternator pulses (cap couple and use a schmidt
trigger)


In theory yes, but if the belt slips then it would mess up the system.

Dwayne

And you have no way of telling when any of the pistons are at TDC (or any
other reference point).

Dwayne

 

[Bob Eldred]

"John Douglas" <jdamja@sbcglobal.net> wrote in message
news:1116945472.214926.252050@g44g2000cwa.googlegroups.com...

I had thought lead-free solder was considered safe.

I was prepared to let a 12 year old begin soldering (under supervision)
until I saw a warning on the back of the package stating that 'this
product contains a known carinogen to the state of Calif' (not exact
quote). Its standard stock lead-free solder from Radio Shack having
96% tin, 4% silver. (Where's the carcinogen in that?)

I am reluctant to let a child use this solder.
Does a safe solder exist?

Thanks,
JD

As you can see, the nay sayers and laissez-faire republicans who could give
a crap about health as they guzzle their six packs and puff on their
cigarettes are out in force poo-pooing the state of California's warnings.
They would rather remain ignorant than to be advised of some problems that
may occur in using that product. Ignorance is bliss and if anybody tries to
advise them, they shine it off as coming from the liberal nut cases in
granola land. The land of fruits, nuts, and flakes. Those warnings may be
overstated but, all they are, after all, are warnings to let people know
that there are certain chemicals involved that have caused cancer in lab
animals, albeit at high dose. You are free to do what you want, eat the
solder, breathe the fumes, whatever. But, a prudent person would take it
under advisement and probably use good ventillation when soldering and not
use it to solder water pipes or food implements without the proper non-toxic
and non-carcinogenic flux. It's common sense.
Bob

 

[Ban]

Bob Eldred wrote:

As you can see, the nay sayers and laissez-faire republicans who
could give a crap about health as they guzzle their six packs and
puff on their cigarettes are out in force poo-pooing the state of
California's warnings. They would rather remain ignorant than to be
advised of some problems that may occur in using that product.
Ignorance is bliss and if anybody tries to advise them, they shine it
off as coming from the liberal nut cases in granola land. The land of
fruits, nuts, and flakes. Those warnings may be overstated but, all
they are, after all, are warnings to let people know that there are
certain chemicals involved that have caused cancer in lab animals,
albeit at high dose. You are free to do what you want, eat the
solder, breathe the fumes, whatever. But, a prudent person would take
it under advisement and probably use good ventillation when soldering
and not use it to solder water pipes or food implements without the
proper non-toxic and non-carcinogenic flux. It's common sense.
Bob

I remember in the fifties when buying shoes, you would look into this big
(wooden!) X-ray box to see if the toes were fitting. Those salesgirls were
operating the machines day in and out. Wonder about theirs and their
offspring health. Is there any data on the net?

--
ciao Ban
Bordighera, Italy

 

[Ban]

signo wrote:

Hello to everybody, first of all sorry for my English (I'm Italian).

I have a circuit, enclosed in a plastic box, where there is power
resistor 1K, 50W and Tmax=200 degrees centigrade.
On the resistor is not present any heat sink.

After few hours that the circuit is working, the temperature measured
on the case of the resistor (Tr) reaches 110 degrees, in a
environmental temperature (Te) of 20 degrees.

My boss says that if Te increases50 degrees (Te = 20+50 =70 degrees),
Tr will increase the same value (Tr = 110+50 = 160 degrees).

I would say that Tr will increase, but not so much, just a little bit.
In my opinion it will be reduced the time for the resistor of
reaching the maximum value.

Is my boss right? Am I right? Are we both wrong?

Thank to everybody is going to help me about this matter.

Massimo,
your boss is right, what counts is the temperature difference. You shouldn't
distrust an engineer so easily, (that's what I suppose he is). )

--
ciao Ban
Bordighera, Italy

 

[Larry Brasfield]

"Ban" <bansuri@web.de> wrote in message news:q4_ke.1438285$35.53676022@news4.tin.it...

signo wrote:
Hello to everybody, first of all sorry for my English (I'm Italian).

I have a circuit, enclosed in a plastic box, where there is power
resistor 1K, 50W and Tmax=200 degrees centigrade.
On the resistor is not present any heat sink.

After few hours that the circuit is working, the temperature measured
on the case of the resistor (Tr) reaches 110 degrees, in a
environmental temperature (Te) of 20 degrees.

My boss says that if Te increases50 degrees (Te = 20+50 =70 degrees),
Tr will increase the same value (Tr = 110+50 = 160 degrees).

I would say that Tr will increase, but not so much, just a little bit.
In my opinion it will be reduced the time for the resistor of
reaching the maximum value.

Is my boss right? Am I right? Are we both wrong?

Thank to everybody is going to help me about this matter.


Massimo,
your boss is right, what counts is the temperature difference. You shouldn't distrust an engineer so easily, (that's what I
suppose he is). )

I suspect that the approximation attributed to
Massimo's boss is the most useful one to be made.
However, it must be recognized as nothing more
than an approximation. The heat loss mechanisms
do not have an inherently linear relationship between
heat flow and temperature differences. For example,
convection loss partially depends on radiation which
varies with the 4th power of absolute temperature.
Chimney effect can cause more air flow and thinner
boundary layers through which the heat must flow
for convection cooling.

--
--Larry Brasfield
email: donotspam_larry_brasfield@hotmail.com
Above views may belong only to me.

 

[Larry Brasfield]

Minor correction inserted below.
"Larry Brasfield" <donotspam_larry_brasfield@hotmail.com> wrote in message news:6m_ke.3$%Q6.1212@news.uswest.net...

"Ban" <bansuri@web.de> wrote in message news:q4_ke.1438285$35.53676022@news4.tin.it...
signo wrote:
Hello to everybody, first of all sorry for my English (I'm Italian).

I have a circuit, enclosed in a plastic box, where there is power
resistor 1K, 50W and Tmax=200 degrees centigrade.
On the resistor is not present any heat sink.

After few hours that the circuit is working, the temperature measured
on the case of the resistor (Tr) reaches 110 degrees, in a
environmental temperature (Te) of 20 degrees.

My boss says that if Te increases50 degrees (Te = 20+50 =70 degrees),
Tr will increase the same value (Tr = 110+50 = 160 degrees).

I would say that Tr will increase, but not so much, just a little bit.
In my opinion it will be reduced the time for the resistor of
reaching the maximum value.

Is my boss right? Am I right? Are we both wrong?

Thank to everybody is going to help me about this matter.


Massimo,
your boss is right, what counts is the temperature difference. You shouldn't distrust an engineer so easily, (that's what I
suppose he is). )


I suspect that the approximation attributed to
Massimo's boss is the most useful one to be made.
However, it must be recognized as nothing more
than an approximation. The heat loss mechanisms
do not have an inherently linear relationship between
heat flow and temperature differences. For example,

convection loss partially depends on radiation which
Should be:

total heat loss partially depends on radiation which

varies with the 4th power of absolute temperature.
Chimney effect can cause more air flow and thinner
boundary layers through which the heat must flow
for convection cooling.

--
--Larry Brasfield
email: donotspam_larry_brasfield@hotmail.com
Above views may belong only to me.

 

[Nog]

<johnlee80@gmail.com> wrote in message
news:1117028222.451659.161560@f14g2000cwb.googlegroups.com...

Hi...

Just a question running through my mind. I know that a 12volt car
battery can't electrocute you.

What if i pass it through a step up dc converter to let say 110v for
the or 240v . Would the car battery now electrocute me if i were to
touch the neg and pos since the power supplied by the battery is almost
equivalent to the power supplied by the house electrical power source?

110 and 240 is 110 and 240. It can stop your heart or make you stab your
self in the eye with a screwdriver.
Don't think a 12 volt battery can't hurt you. The current can fry your ass.
Think about your wedding ring turning white hot..

 

[vic]

johnlee80@gmail.com wrote:

Hi...

Just a question running through my mind. I know that a 12volt car
battery can't electrocute you.

What if i pass it through a step up dc converter to let say 110v for
the or 240v . Would the car battery now electrocute me if i were to
touch the neg and pos since the power supplied by the battery is almost
equivalent to the power supplied by the house electrical power source?

Yes it could hurt you, the difference is that you must touch both
terminals at once since there is no ground path.

 

[Ban]

Larry Brasfield wrote:

Minor correction inserted below.
"Larry Brasfield" <donotspam_larry_brasfield@hotmail.com> wrote in
message news:6m_ke.3$%Q6.1212@news.uswest.net...
"Ban" <bansuri@web.de> wrote in message
news:q4_ke.1438285$35.53676022@news4.tin.it...
signo wrote:
Hello to everybody, first of all sorry for my English (I'm
Italian). I have a circuit, enclosed in a plastic box, where there is
power
resistor 1K, 50W and Tmax=200 degrees centigrade.
On the resistor is not present any heat sink.

After few hours that the circuit is working, the temperature
measured on the case of the resistor (Tr) reaches 110 degrees, in a
environmental temperature (Te) of 20 degrees.

My boss says that if Te increases50 degrees (Te = 20+50 =70
degrees), Tr will increase the same value (Tr = 110+50 = 160
degrees). I would say that Tr will increase, but not so much, just a
little
bit. In my opinion it will be reduced the time for the resistor of
reaching the maximum value.

Is my boss right? Am I right? Are we both wrong?

Thank to everybody is going to help me about this matter.


Massimo,
your boss is right, what counts is the temperature difference. You
shouldn't distrust an engineer so easily, (that's what I suppose he
is). )


I suspect that the approximation attributed to
Massimo's boss is the most useful one to be made.
However, it must be recognized as nothing more
than an approximation. The heat loss mechanisms
do not have an inherently linear relationship between
heat flow and temperature differences. For example,

convection loss partially depends on radiation which
Should be:
total heat loss partially depends on radiation which

varies with the 4th power of absolute temperature.
Chimney effect can cause more air flow and thinner
boundary layers through which the heat must flow
for convection cooling.

Unfortunately you cannot rely on the radiation, it will be a miniscule
amount compared to the convection, because he says the box is closed, so
radiation can only be from the outer surface, which he didn't report. I
presume it will be half way between inside and outside, if the surface is
0.1mq and e=0.8, then with 338K 0.55W is radiated and with 408K 1W is
radiated, hardly much in comparison to the total power, but it makes a good
excuse to the boss. THX to Larry
The formula to impress the boss:
surfaceArea(m^2) * e(0.5...1) * constant 5.67e-8(W/(m^4 * K^4)) *
(emitterK^4 - ambientK^4)/(emitterK - ambientK)
--
ciao Ban
Bordighera, Italy

 

[John Popelish]

signo wrote:

Hello to everybody, first of all sorry for my English (I'm Italian).

I have a circuit, enclosed in a plastic box, where there is power
resistor 1K, 50W and Tmax=200 degrees centigrade.
On the resistor is not present any heat sink.

After few hours that the circuit is working, the temperature measured
on the case of the resistor (Tr) reaches 110 degrees, in a
environmental temperature (Te) of 20 degrees.

My boss says that if Te increases50 degrees (Te = 20+50 =70 degrees),
Tr will increase the same value (Tr = 110+50 = 160 degrees).

I would say that Tr will increase, but not so much, just a little bit.
In my opinion it will be reduced the time for the resistor of reaching
the maximum value.

Is my boss right? Am I right? Are we both wrong?

Thank to everybody is going to help me about this matter.

Massimo

About the most I can say is that Tr will not rise more than Te does,

though it is possible that Tr will rise almost as much as Te does. At
low temperatures (low not being defined) heat is transferred primarily
by by conduction and convection. Conduction is a fairly linear
process that passes energy with a temperature rise about proportional
to the energy flow. Convection is also fairly linear. But in
parallel with these two mechanisms is radiation, and it is decidedly
nonlinear. Radiation passes energy in proportion to the 4th power of
absolute temperature difference. So as the temperature of box and
resistor rise, there is some absolute temperature at which radiation
will overtake both conduction and convection as the dominate transfer
mechanism. I don't know if that temperature is any where near the
temperatures you are talking about, however.

So your is correct, in the limit for low temperatures, and you are
right above some particular temperature. An experiment is the best
way to settle this argument.

 

[John Popelish]

MarkMc wrote:

For my home brewery I need to know if a container has liquid past a
certain level, and if it is, turn on a pump.

Can anybody suggest a way of doing this? I don't really want to use
anything which floats in the liquid, I just need to know if the liquid
is past a certain point/level.

If there's anything "off the shelf" which I can screw in to the
container, then that would be fantastic.

Regards,
Mark

You might Google "capacitive proximity". These are devices that

switch an output signal when conductive material gets close to their
face. Some can operate through glass or plastic container walls.
http://www.turck-usa.com/products/sensors/capacitive/Barrel_with_Potted-in_Cable/

 

[Rich Grise]

On Wed, 25 May 2005 06:37:02 -0700, johnlee80 wrote:

Hi...

Just a question running through my mind. I know that a 12volt car
battery can't electrocute you.

What if i pass it through a step up dc converter to let say 110v for
the or 240v . Would the car battery now electrocute me if i were to
touch the neg and pos since the power supplied by the battery is almost
equivalent to the power supplied by the house electrical power source?

The way your question is phrased, the answer is no. The 12V from the
battery won't hurt you any more if it's supplying a load than if it's
not (this not counting open wounds (neglibile body resistance), hot
wrenches (you can weld with a 12V battery, under the right conditions),
and that sort of thing, which is a different question). But the 12V is
still 12V.

But the 110 or 240 definitely will at least give you a painful jolt,
and can very easily burn you or kill you.

Hope This Helps!
Rich