Chip with simple program for Toy

[Frnak McKenney]

On Mon, 26 May 2008 15:45:54 -0700 (PDT), Kasterborus <kasterborus@yahoo.com> wrote:

I just hooked up a Sharp GP2D12 IR range sensor to a scope and saw
that the output is very noisy. The sensor updates at 25Hz so I was
thinking that if I were to add some kind of 25Hz low pass filter to
the output that would clean things up.

You might check the archives of comp.robotics.misc. I recall several
discussions about the amount of current that some (all?) of the
Sharp IR rangers consumed.

I do know from personal experience that an IR remote control unit
such as the Siemens SFH506 (admittedly a slightly different device)
can go from "flaky" to "fantastic" when a 100Ohm/100uF filter is
added to keep the device's voltage up.

Hope this helps...


Frank McKenney
--
Government is the great fiction, through which everybody
endeavors to live at the expense of everybody else.
-- Frederic Bastiat, French Economist
--
Frank McKenney, McKenney Associates
Richmond, Virginia / (804) 320-4887
Munged E-mail: frank uscore mckenney ayut mined spring dawt cahm (y'all)

 

[Tom Biasi]

<x_onix2000@yahoo.com> wrote in message
news:9b71bf12-29fb-4db9-8622-dc936a9ef9b1@8g2000hse.googlegroups.com...

hay watsup , i m in need of little help i have a project of solar
based lighting system , motin sensors are also incarporated, battery
will b charged by solar energy , if the battery is not charged
properly then it should b charged by the main power supply.first i
have to sense that battery is naot charged properly then i have to
charge it frm main power supply ......i need a help in making these
logic circuits
hey dude,

u need 2 describe bttr how u will incarporate da motin sensors.
l8tr,
Tom

 

[Tom Biasi]

<x_onix2000@yahoo.com> wrote in message
news:9b71bf12-29fb-4db9-8622-dc936a9ef9b1@8g2000hse.googlegroups.com...

hay watsup , i m in need of little help i have a project of solar
based lighting system , motin sensors are also incarporated, battery
will b charged by solar energy , if the battery is not charged
properly then it should b charged by the main power supply.first i
have to sense that battery is naot charged properly then i have to
charge it frm main power supply ......i need a help in making these
logic circuits
hey dude,

u need 2 describe bttr how u will incarporate da motin sensors.
l8tr,
Tom

 

[Phil Allison]

"daestrom"

plonk

** Pathetic wanker.




.... Phil

 

[Phil Allison]

"mowhoong"

I noticed Electroluminescent Vinyls paste out side the taxi door for
advertisment without any protection, I remenber this kind of displays
need high ac voltage to triger. I am wondering would this pose any
danger in electric shock when this vinyls gradually degrade over
time ?
Can any members help me in this question. Thank you

** In general, the ** AC drive voltage ** used to light to an
electroluminescent panel is high frequency (ie 10s of kHz) and with rather a
low current level - ie only a few mAs.

Which is not an electrocution hazard, despite the fact that the voltage is
moderately high.



...... Phil

 

[Phil Allison]

"mowhoong"

I noticed Electroluminescent Vinyls paste out side the taxi door for
advertisment without any protection, I remenber this kind of displays
need high ac voltage to triger. I am wondering would this pose any
danger in electric shock when this vinyls gradually degrade over
time ?
Can any members help me in this question. Thank you

** In general, the ** AC drive voltage ** used to light to an
electroluminescent panel is high frequency (ie 10s of kHz) and with rather a
low current level - ie only a few mAs.

Which is not an electrocution hazard, despite the fact that the voltage is
moderately high.



...... Phil

 

[Phil Allison]

"Jamie"

Why, are you a lawyer collecting information for a case or just one
of those looking for free money ?

I ask this because once in a while we get people in here asking questions
looking for answers for devious reasons.

** Only " once in a while " ????????????????

B O L L O C K S !!!!!!!!!

Its 99 % of the time - at least.



....... Phil

 

[Phil Allison]

"Jamie"

Why, are you a lawyer collecting information for a case or just one
of those looking for free money ?

I ask this because once in a while we get people in here asking questions
looking for answers for devious reasons.

** Only " once in a while " ????????????????

B O L L O C K S !!!!!!!!!

Its 99 % of the time - at least.



....... Phil

 

[Lord Garth]

<ngdbud@gmail.com> wrote in message
news:f90b4044-a9b2-4922-baa1-6002c0794b0c@34g2000hsh.googlegroups.com...

Hey everybody. I am a hobbyist in the field of electronics with no
formal training. I have a pretty good understanding of components but
know basically nothing about systems as a whole. I got my hands on an
old computer supply and read about converting them for use as a lab
power supply. The directions said the poower supply needs to be loaded
to run, For their 450 watt power supply a 10 ohm 10 watt resistor was
used. My power supply is only a 90 watt, 10 ohms sounds like overkill.
I have a 250 ohm power resistor laying around. by my calculations this
will pull about 45 milliamps at 12 volts. Does this sound like enough
to load my 90 watt power supply? if not how many amps will it take?
thanks in advance!

Is that an old 90 watt PCXT power supply???? Those needed a load similar
to an ST506 hard drive or an amp or so on the 12 volt line. In any case,
you
don't say what the current capability is of the 12 volt output. 90 watts is
likely
the total supply capability inclusive of all its outputs.

 

[Tom Biasi]

"Dave.H" <the1930s@googlemail.com> wrote in message
news:7bf4fd01-864f-42ec-b13b-cd5f9c06b3cb@j33g2000pri.googlegroups.com...

This may be a stupid question, but I'm about to build a crystal radio
(http://www.bobsdata.com/crystal_radio/index.html) and I want to use a
little audio amp (Cat. KC5152 @ www.jaycar.com.au), and was wondering
if I'd need the matching preamp (Cat. KC5172 @ Jaycar) for the crystal
radio's high impedance output. Any help on this appreciated.

Thanks,
Dave

Hi Dave,
Crystal sets are fun to build and can teach something about radio and
electronics.
They are meant to 'power' a high impedance headphone. Yes you can amplify
the signal. You would need an amp with high input impedance and you most
likely would need additional amplification to drive the speaker. Keep in
mind that all the noise is amplified also.
IMHO: Much more fun with just the phones, but by all means experiment.

Tom

 

[BobW]

"Tom Biasi" <tombiasi@optonline.net> wrote in message
news:lL-dndLBKIY5Q6DVnZ2dnUVZ_oPinZ2d@giganews.com...

"Dave.H" <the1930s@googlemail.com> wrote in message
news:7bf4fd01-864f-42ec-b13b-cd5f9c06b3cb@j33g2000pri.googlegroups.com...
This may be a stupid question, but I'm about to build a crystal radio
(http://www.bobsdata.com/crystal_radio/index.html) and I want to use a
little audio amp (Cat. KC5152 @ www.jaycar.com.au), and was wondering
if I'd need the matching preamp (Cat. KC5172 @ Jaycar) for the crystal
radio's high impedance output. Any help on this appreciated.

Thanks,
Dave


Hi Dave,
Crystal sets are fun to build and can teach something about radio and
electronics.
They are meant to 'power' a high impedance headphone. Yes you can amplify
the signal. You would need an amp with high input impedance and you most
likely would need additional amplification to drive the speaker. Keep in
mind that all the noise is amplified also.
IMHO: Much more fun with just the phones, but by all means experiment.

Tom

Yep, all the fun is knowing that what you're hearing is being directly
powered by the transmitter. I remember what a blast it was building my first
crystal set -- and that was BEFORE radio had even been invented!

Of course, if get into trouble, you can always add an antenna amplifier, and
then maybe an intermediate down converter, and I suppose a narrow band
filter followed by detector and a high-powered audio amplifier. That would
work, too.

Bob
--
== NOTE: I automatically delete all Google Group posts due to uncontrolled
SPAM ==

 

[Tom Biasi]

"BobW" <nimby_NEEDSPAM@roadrunner.com> wrote in message
news:2LCdnY3rtvESbaDVnZ2dnUVZ_ovinZ2d@giganews.com...

"Tom Biasi" <tombiasi@optonline.net> wrote in message
news:lL-dndLBKIY5Q6DVnZ2dnUVZ_oPinZ2d@giganews.com...

"Dave.H" <the1930s@googlemail.com> wrote in message
news:7bf4fd01-864f-42ec-b13b-cd5f9c06b3cb@j33g2000pri.googlegroups.com...
This may be a stupid question, but I'm about to build a crystal radio
(http://www.bobsdata.com/crystal_radio/index.html) and I want to use a
little audio amp (Cat. KC5152 @ www.jaycar.com.au), and was wondering
if I'd need the matching preamp (Cat. KC5172 @ Jaycar) for the crystal
radio's high impedance output. Any help on this appreciated.

Thanks,
Dave


Hi Dave,
Crystal sets are fun to build and can teach something about radio and
electronics.
They are meant to 'power' a high impedance headphone. Yes you can amplify
the signal. You would need an amp with high input impedance and you most
likely would need additional amplification to drive the speaker. Keep in
mind that all the noise is amplified also.
IMHO: Much more fun with just the phones, but by all means experiment.

Tom


Yep, all the fun is knowing that what you're hearing is being directly
powered by the transmitter. I remember what a blast it was building my
first crystal set -- and that was BEFORE radio had even been invented!

Of course, if get into trouble, you can always add an antenna amplifier,
and then maybe an intermediate down converter, and I suppose a narrow band
filter followed by detector and a high-powered audio amplifier. That would
work, too.

Bob
--
== NOTE: I automatically delete all Google Group posts due to uncontrolled
SPAM ==


I think you got my point precisely.

Tom

 

[Tom Biasi]

"Dave.H" <the1930s@googlemail.com> wrote in message
news:823ca1ca-d17b-4b83-9d97-8cefa107d48d@a9g2000prl.googlegroups.com...

On May 29, 8:37 am, "Tom Biasi" <tombi...@optonline.net> wrote:
"Dave.H" <the19...@googlemail.com> wrote in message

news:7bf4fd01-864f-42ec-b13b-cd5f9c06b3cb@j33g2000pri.googlegroups.com...

This may be a stupid question, but I'm about to build a crystal radio
(http://www.bobsdata.com/crystal_radio/index.html) and I want to use a
little audio amp (Cat. KC5152 @www.jaycar.com.au), and was wondering
if I'd need the matching preamp (Cat. KC5172 @ Jaycar) for the crystal
radio's high impedance output. Any help on this appreciated.

Thanks,
Dave

Hi Dave,
Crystal sets are fun to build and can teach something about radio and
electronics.
They are meant to 'power' a high impedance headphone. Yes you can amplify
the signal. You would need an amp with high input impedance and you most
likely would need additional amplification to drive the speaker. Keep in
mind that all the noise is amplified also.
IMHO: Much more fun with just the phones, but by all means experiment.

Tom

So I do need the preamp? I intend on using headphones, most of the
time, but sometimes I like to have a bit of background noise, and
headphones just don't work for that. This amp will probably also be
used with the Hiker's One regenerative radio I'm also planning on
building.

Use a preAmp.

 

[Tom Biasi]

"Dave.H" <the1930s@googlemail.com> wrote in message
news:823ca1ca-d17b-4b83-9d97-8cefa107d48d@a9g2000prl.googlegroups.com...

On May 29, 8:37 am, "Tom Biasi" <tombi...@optonline.net> wrote:
"Dave.H" <the19...@googlemail.com> wrote in message

news:7bf4fd01-864f-42ec-b13b-cd5f9c06b3cb@j33g2000pri.googlegroups.com...

This may be a stupid question, but I'm about to build a crystal radio
(http://www.bobsdata.com/crystal_radio/index.html) and I want to use a
little audio amp (Cat. KC5152 @www.jaycar.com.au), and was wondering
if I'd need the matching preamp (Cat. KC5172 @ Jaycar) for the crystal
radio's high impedance output. Any help on this appreciated.

Thanks,
Dave

Hi Dave,
Crystal sets are fun to build and can teach something about radio and
electronics.
They are meant to 'power' a high impedance headphone. Yes you can amplify
the signal. You would need an amp with high input impedance and you most
likely would need additional amplification to drive the speaker. Keep in
mind that all the noise is amplified also.
IMHO: Much more fun with just the phones, but by all means experiment.

Tom

So I do need the preamp? I intend on using headphones, most of the
time, but sometimes I like to have a bit of background noise, and
headphones just don't work for that. This amp will probably also be
used with the Hiker's One regenerative radio I'm also planning on
building.

Use a preAmp.

 

[Claude]

"Jamie" <jamie_ka1lpa_not_valid_after_ka1lpa_@charter.net> wrote in message
news:6Ae%j.10$bn7.7@newsfe07.lga...

mowhoong wrote:
I noticed Electroluminescent Vinyls paste out side the taxi door for
advertisment without any protection, I remenber this kind of displays
need high ac voltage to triger. I am wondering would this pose any
danger in electric shock when this vinyls gradually degrade over
time ?
Can any members help me in this question. Thank you
regards

Why, are you a lawyer collecting information for a case or just one
of those looking for free money ?

I ask this because once in a while we get people in here asking questions
looking for answers for devious reasons.



http://webpages.charter.net/jamie_5"

Hey pal! It's only 99% of the lawyers that give the others a bad name!

 

[Claude]

"Jamie" <jamie_ka1lpa_not_valid_after_ka1lpa_@charter.net> wrote in message
news:6Ae%j.10$bn7.7@newsfe07.lga...

mowhoong wrote:
I noticed Electroluminescent Vinyls paste out side the taxi door for
advertisment without any protection, I remenber this kind of displays
need high ac voltage to triger. I am wondering would this pose any
danger in electric shock when this vinyls gradually degrade over
time ?
Can any members help me in this question. Thank you
regards

Why, are you a lawyer collecting information for a case or just one
of those looking for free money ?

I ask this because once in a while we get people in here asking questions
looking for answers for devious reasons.



http://webpages.charter.net/jamie_5"

Hey pal! It's only 99% of the lawyers that give the others a bad name!

 

[Lord Garth]

<ngdbud@gmail.com> wrote in message
news:60f7c5e0-3872-419f-9980-00fee42a0885@s50g2000hsb.googlegroups.com...
On May 28, 2:52 pm, "Lord Garth" <lga...@tantalus.net> wrote:

ngd...@gmail.com> wrote in message

snip
Sorry, i'm not sure what kind of ower supply it is, all i can tell you
is the model number sfx-1209f. and yes, 90 watts is the overall out
put. 1.5 amps are availble on the 12 volt channel. here is another
though, since i only plan on using the 12v channel would it be a
better idea to load the 5 volt channel? Thinking out loud.... I'll
probablly go with jamies ide and just try it. obviously I'll have to
bost the resistance since less current is going to be pulled at 5v.
perhaps some led's? i'll ned a few of em to pull enough amperage...

As a hobbyist, you should build your first power supply! At 1.5A,
you can easily get this with a either a linear regulator or you can opt
for a switching regulator. In either case, the parts count is low. A
quick google search should get you some part numbers from which
to start.

If you still wish to use the computer power supply, load it with an
incandescent bulb. A 6 volt bulb on the 5 volt output is not a problem.

 

[Bob Eld]

"ted" <strnbrg59@gmail.com> wrote in message
news:0da35bb4-12a5-4b99-84a2-977ebfa4d906@m36g2000hse.googlegroups.com...

I'm getting strange results from an optocoupler (aka optoisolator, and
this is the kind with transistor output). In brief: nothing I do
seems to make the transistor "conduct", except very feebly.

Here's my setup:

Diode anode: 0V/1.07V, 0.4mA
Diode cathode: ground

Transistor collector: connected to a 330 Ohm resistor which is
connected to 4.92V.
Transistor emitter: ground
Transistor base: open

When the diode anode is at 0V, the transistor collector is, as one
would expect, at 4.92V.
But when I give the diode anode 1.07V, the transistor collector drops
to just 4.88V. I want it to go down to 0V and I don't understand why
that's not happening.

The diode in an optocoupler is an Infrared LED. It takes more than 1.07
volts to turn on. You can see this with the feeble current of 400uA you
measure. Run the diode on 5 to 10 mA. The voltage should be nearly two
volts.

If this thing has to run fairly fast, place a 10 K resistor from the base of
the transistor to ground. The open base will slow operation appreciably.

 

[Wim Lewis]

In article <eaab71c3-4815-4de7-9af7-c974c8d1222d@s50g2000hsb.googlegroups.com>,
ted <strnbrg59@gmail.com> wrote:

You should check the maximum diode current, too -- that 10mA is
certainly suggestive of what you ought to be able to do. Figure 10mA
in, 2mA out, means you'll need to use at least a 2500 ohm resistor to
pull the collector all the way down.

Thanks, and would you please explain why 2500 ohm is the correct
resistance, indeed why the resistance at that point makes any
difference to what the voltage is going to be at the collector pin?
(I was under the impression that when the transistor is "on", it has
no internal resistance...)

It has a *pretty low* internal resistance, as long as the current flowing
through it is less than some value. That value depends on (for a normal
transistor) the voltage/current on its base, or (for a photo-transistor)
the amount of light hitting it.

"On" and "off" are just shorthand. "On" is a short way of saying
"there's plenty of base current (or light), which means that the
transistor will allow as much current as I'm likely to give it".
"Off" is a short way of saying "there's not much base current (or
light), so the transistor will allow so little current through that
I can ignore it." In between "on" and "off", the transistor is in
what's called the "active" region, and it acts like a controllable
current-limiter.

That's what the "current transfer ratio" on the optocoupler data sheet
is talking about: it's the ratio of input current (through the LED) to
output current (through the output transistor). If you put 1 mA through
the LED, it emits X amount of light; part of that light hits the
transistor; as a result the transitor allows Y amount of current ---
the ratio 1mA:Y is the current transfer ratio.


The 2500 ohms Tim Wescott mentions is because there's a limit to
how much current the LED in the optocoupler will take: if you max
it out at 10 mA (which is an educated guess at what the limit is;
the data sheet will say for sure), then the transistor half will
be allowing 2 mA (that's 10 mA multiplied by the current transfer
ratio). If you can only draw 2mA of current, the resistor has to
be at least 2500 ohms in order to swing 5V (2500 ohms * 2 mA = 5V).


--
Wim Lewis <wiml@hhhh.org>, Seattle, WA, USA. PGP keyID 27F772C1

 

[Ecnerwal]

In article
<dadb5398-6838-4895-9cf6-970c7de09c79@g16g2000pri.googlegroups.com>,
sodaant@gmail.com wrote:

I'm setting up a hobbyist electronics lab. What kind of equipment
should I buy to equip this lab? My budget is $3000.

"What you need" depends a huge amount on what you plan to do. Radio,
microprocessors, audio, ...

One approach is to buy stuff as your hobby project of the moment
requires - that will tend to match up your equipment to what you are
actually doing, or have done, rather than tying up bunches of money in
things you never use for your particular projects. If you are somewhat
vague about projects, start in with things you need - you can build
power supplies, buy kits to build meters, etc.

Oscilloscope (but there's a huge range, depending on what you plan to
do.) Big differences are Analog .vs. Digital, number of channels, and
speed.

Function generator

Frequency counter (perhaps, depending...)

Spectrum analyzer (perhaps, depending, but even old ones will probably
blow your budget, so perhaps not)

Soldering tools - a combined iron/hot air system is one approach.

Anti-static (not essential for some things, but cheap enough to just do
right once - get a good rubber bench mat and wrist-band)

meter(s) - multimeter, perhaps more than one or some dedicated less
capable meters (advantage being that you can look at two parameters at
once if you have more than one meter). Simpler meters have the advantage
of being dirt cheap. One that does L/C (inductance/capacitance) is
invaluable, especially if getting used parts by scrapping old equipment,
as the markings are often obscure - or if winding your own inductors.

Power supplies

Parts to play with - resistors, capacitors, transistors, diodes,
op-amps, ...

cables, wires, breadboards etc.

--
Cats, coffee, chocolate...vices to live by