Chip with simple program for Toy

[PeteS]

Fred Bartoli wrote:

Jonathan Kirwan a écrit :

On Sun, 22 Oct 2006 11:48:33 +0200, Fred Bartoli
fred._canxxxel_this_bartoli@RemoveThatAlso_free.fr_AndThisToo> wrote:

Woaw... 2 transistors and 3 resistors.

Just use the right transistor for this: logic level mosfet.


Makes sense. Particularly in the 120mA region.

I know that just about any cheap NPN and PNP will work in the circuit
I gave. Junk box stuff. I'm not nearly as familiar with MOSFETs. Can
you point me to a good example of any one that would work great with
3.5V on its gate? I'd like to learn more, myself.


Sure. Just plug logic level mosfet or digital mosfet into any mos
manufacturer website and you'll find plenty of.

For example http://www.fairchildsemi.com/ds/FD%2FFDV301N.pdf should fit
the bill.
Or the more capable http://www.fairchildsemi.com/ds/ND%2FNDS331N.pdf

Even the good old 2N7002, if the logic is 5V CMOS may just do it. I
didn't checked at 120mA, but given the price, just use 2, or run the
leds lower than 20mA each.

The PMV45EN would easily handle this; SOT23, 5.4A ID(max), Vgs(th) 2.2V
(max across temperature) for ID = 1mA.

I use this as a power switch from logic levels (3.3V system) and I've
never had an issue with it.

Interestingly, the datasheet also specs the sub-threshold leakage
currents, which is unusual but useful.

Cheers

PeteS

 

Thanks for your help and for the diagram, one small problem though. My
second power source is 9 volts not 4.5 volts. The chip is running of 5
volts and leds are running off 9 volts operating at 4.5 volts. So is it
better to use individual resistors to each led instead of one higher 1
watt resistor?

Thanks again you guys rock.

 

[PeteS]

Digitmode@gmail.com wrote:

Thanks for your help and for the diagram, one small problem though. My
second power source is 9 volts not 4.5 volts. The chip is running of 5
volts and leds are running off 9 volts operating at 4.5 volts. So is it
better to use individual resistors to each led instead of one higher 1
watt resistor?

Thanks again you guys rock.

It's usually best to use a resistor for each LED to prevent current

hogging from the lowest resistance LED (they will have varying
characteristics).

Cheers

PeteS

 

[Rich Grise]

On Sun, 22 Oct 2006 10:15:01 -0700, Digitmode wrote:

Thanks for your help and for the diagram, one small problem though. My
second power source is 9 volts not 4.5 volts. The chip is running of 5
volts and leds are running off 9 volts operating at 4.5 volts. So is it
better to use individual resistors to each led instead of one higher 1
watt resistor?

Thanks again you guys rock.

It's better to put LEDs in series, unless there's a serious variation
in brightness at the same current, in the same batch.

Just add up the VF's or, say, three LEDs and calculate your resistor
as (9V - (Vftotal)) / Iled, unless I've gotten it upside down. ;-)

That way your switch transistor doesn't have to handle all of that current,
and you waste much less power in dropping resistors.

Good Luck!
Rich

 

[wolly]

See bad experiences by people who tried experimenting with Lion cells.
Dont try 220v its dangerous.
Better discard the battery and get a fresh one,they are cheap.
If your phone was not connected to the battery when it fell in the
water or if you removed the battery immedieatly when it fell in water
it is ok or else your phone is also failed.

 

[Charles Schuler]

"Charles Schuler" <charleschuler@comcast.net> wrote in message
news:X6adnRhmY-D2_dfYnZ2dnUVZ_oOdnZ2d@comcast.com...

"Bret Cahill" <BretCahill@aol.com> wrote in message
news:1162498946.796294.160040@m7g2000cwm.googlegroups.com...
Would alternating a lot of capacitors and inductors in series
approximate a Slinky spring?

A simple model would be a parallel resonant circuit (RLC). L and C would
dictate the oscillation frequency and R the damping factor.

But, if you are talking about a slinky walking down a flight of stairs,
forget about simple models.

 

[John Popelish]

lerameur wrote:

Yes, how about putting the voltage divider at the input supply. ?
The output should be fairly independent of the exact supply

voltage, so this is probably not a very good method.

Here is the chip I am using:
http://www.taosinc.com/product_detail.asp?cateid=20&proid=2

Also I saw about 3%-4% of ripple (noise).

Are you sure your light source is perfectly stable (no ripple)?

Maybe just adding a small
capacitor with a resistance in parallel (from Vout to ground)? or would
a feedback op-amp low pass filter be a better idea?

An RC could be used as a low pass filter. A voltage divider
that has a small range (100% to 80% of input signal)
followed by an RC might also work. This device should have
a pretty good zero output for zero signal, so variable
scaling (zero in equals zero out, regardless of the scale
factor) is probably a lot better than variable offset.

 

[Homer J Simpson]

"Bret Cahill" <BretCahill@aol.com> wrote in message
news:1162498946.796294.160040@m7g2000cwm.googlegroups.com...

Would alternating a lot of capacitors and inductors in series
approximate a Slinky spring?

In what sense?


--
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[default]

On 31 Oct 2006 11:27:40 -0800, "ZhangLu" <Dr.chongff@gmail.com> wrote:

Hi, I'm looking for a schematic to construct a anti rust device, to be
fitted to a 12v car. Can anyone help?

I think they only work well with boats where the metal parts are
always in contact with the water. The idea is simple and only takes
an op amp and perhaps driver transistor. You measure the voltage
being produced by the galvanic action of dissimilar metals and apply
enough current to another electrode to cancel the galvanic voltage.

Unless all the parts are bonded - connected together electrically - it
won't work. Unless the electrode and parts being protected aren't wet
at the same time by the same electrolyte, it won't work.

If it were that easy - you could just bolt a sacrificial anode (zinc)
to the car and be done with it - that technique has worked well for
many years in boats.

Things to search for are "active cathodic protection"

I knew a guy with a boat who was paying the dockmaster to look after
it. He complained that the zincs, he added, where being eaten away in
no time - and plating out on the bronze parts below the water line.
So I went out to look at it - it had an active rust prevention scheme
already in place. That suggests, to me, that had he had galvanized
fittings below the water line they might be eaten away leaving the
iron exposed - but I don't know for a fact. I just told him to use
one system or the other, but not both.

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[nobody]

Years ago there was a product called "Rust Buster" that was a small
impressed current device attached to your battery and having several
anodes attached to the autobody parts. IT DID NOT WORK.

For this system to work the vehicle must be submerged in an electrolyte.
Condensation, and rain doesn't provide an adequate layer for cathodic
protection.

default wrote:

On 31 Oct 2006 11:27:40 -0800, "ZhangLu" <Dr.chongff@gmail.com> wrote:


Hi, I'm looking for a schematic to construct a anti rust device, to be
fitted to a 12v car. Can anyone help?


I think they only work well with boats where the metal parts are
always in contact with the water. The idea is simple and only takes
an op amp and perhaps driver transistor. You measure the voltage
being produced by the galvanic action of dissimilar metals and apply
enough current to another electrode to cancel the galvanic voltage.

Unless all the parts are bonded - connected together electrically - it
won't work. Unless the electrode and parts being protected aren't wet
at the same time by the same electrolyte, it won't work.

If it were that easy - you could just bolt a sacrificial anode (zinc)
to the car and be done with it - that technique has worked well for
many years in boats.

Things to search for are "active cathodic protection"

I knew a guy with a boat who was paying the dockmaster to look after
it. He complained that the zincs, he added, where being eaten away in
no time - and plating out on the bronze parts below the water line.
So I went out to look at it - it had an active rust prevention scheme
already in place. That suggests, to me, that had he had galvanized
fittings below the water line they might be eaten away leaving the
iron exposed - but I don't know for a fact. I just told him to use
one system or the other, but not both.

----== Posted via Newsfeeds.Com - Unlimited-Unrestricted-Secure Usenet News==----
http://www.newsfeeds.com The #1 Newsgroup Service in the World! 120,000+ Newsgroups
----= East and West-Coast Server Farms - Total Privacy via Encryption =----

 

[jasen]

On 2006-10-31, ZhangLu <Dr.chongff@gmail.com> wrote:

Hi, I'm looking for a schematic to construct a anti rust device, to be
fitted to a 12v car. Can anyone help?

I've seen the device (well a mockup on a coulter) I have no idea how they
"polarise the paint" or whatever it is they actually do, or if it works.

Bye.
Jasen

 

[Tim Auton]

Rod'sInfoQuest <remcg@tesco.net> wrote:

Hi,
As a complete electronics novice I am struggling to get a LM35 to work
properly. I know it should be simple but for some reason it is not
working and wondered if anyone has any suggestions. I have a string of
6 sensors with a live wire from a 9v battery connected to each via a
rotary switch. The ground goes back to the battery and I measure the
voltage between the middle pin and the ground.
The output of the 6 is different by up to 100 mV at the same
temperature. The output often seems to be around 300 mV when the
temperature is about 20 C, and only changes very slowly with increased
temperature, to the extent that I have no confidence in the output.

Slow response is expected in air - check the graph in the top-right
corner of page 5 of the National Semiconductor LM35 datasheet "Thermal
Response In Still Air". It takes about 3 minutes to stabilise at its
final value.

Not waiting long enough will give you inaccurate readings, which will
also make comparisons between units inaccurate.

I'd suggest connecting all 6 in parallel to your 9V battery (i.e. remove
the rotary switch). Ensure they should all be at the same temperature -
fairly close together, with no heat sources (lights, power supplies,
central heating...) very close to them. Then wait a good 5-10 minutes
before measuring the output.


Tim

 

[Homer J Simpson]

"Bill Bowden" <wrongaddress@att.net> wrote in message
news:1162441030.247284.120490@b28g2000cwb.googlegroups.com...

I need to close a relay 30 seconds after a signal is present, and open
the same relay 30 seconds after the signal drops out, (+/- 10%). I'm
considering using a RC network on the input of a comparator so that the
cap charges and closes the relay 30 seconds after the input is present,
and opens the relay 30 seconds after the input falls. There will be a
long period between on/off so the cap can fully charge and discharge.
There is also some feedback to avoid relay chatter. I need to use
fewest parts possible.

Is this about as simple as can be, or is there a better approach?

I would buy an off the shelf relay with time delays.

 

[Lionel]

On 1 Nov 2006 14:47:01 -0800, "Rod'sInfoQuest" <remcg@tesco.net>
opined:

Hi,
As a complete electronics novice I am struggling to get a LM35 to work
properly. I know it should be simple but for some reason it is not
working and wondered if anyone has any suggestions. I have a string of
6 sensors with a live wire from a 9v battery connected to each via a
rotary switch. The ground goes back to the battery and I measure the
voltage between the middle pin and the ground.

Sounds like you've wired them up incorrectly, or possibly they're
oscillating because you've wired them to long leads without any bypass
circuitry. Check the full data sheet below, paying paticular attention
to the "Typical Applications" section:
<http://www.national.com/pf/LM/LM35.html>

--
W
. | ,. w , "Some people are alive only because
\|/ \|/ it is illegal to kill them." Perna condita delenda est
---^----^---------------------------------------------------------------

 

[Homer J Simpson]

"Ge0rge Marutz" <gerbermultit00l@yahoo.com> wrote in message
news:1162479756.328830.24810@i42g2000cwa.googlegroups.com...

I found a single diode in a TO-220 package that can carry 30A. The
problem being I would need to place two diodes in parallel to carry a
maximum of 60A. My concern is whether or not the devices will share
current evenly. If power dissipation is slightly higher on one than
the other, won't it self heat more and create an even higher
non-distribution of current (Vf drop decreases as the device heats).

Wire to one diode only then bridge to the second. Reverse this for the
output. It'll help some.


--
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+ Required crap appended to avoid restrictions imposed by brain +
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+
+ Server Response: '441 Posting Failed (Rejected by POST filter)', +
+ Port: 119, Secure(SSL): No, Server Error: 441,
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[Ge0rge Marutz]

How about something like a 0.001ohm precision current shunt? This
would work for prototype purposes but not volume production.

Ge0rge

Placing a low value high wattage resistor in series with each of the
diodes will distribute load evenly. I have seen this done with Diodes
before, but not Schottky, so there may be issues related to that.

-Lares


Both diodes will be bolted next to each other on a liquid cooled
aluminum heat sink.

Thanks,

George

 

[Phil Allison]

"Anthony Fremont Asinine Cunthead & total Moron "

Is it possible to bounce signals off the moon to other places on
earth? (i.e. use the moon as a comm satellite)


http://www.google.com.au/search?hl=en&q=moon+bounce+ham+radio+&btnG=Search&meta=

It's called EME.

** It is called " moon bounce " by radio amateurs world wide and all
normal people.

EME is a merely a ham acronym used only by ASD fucked wankers.






....... Phil

 

[Avi Schwartz]

On 2006-11-02 22:32:56 -0800, "Phil Allison" <philallison@tpg.com.au> said:

"Anthony Fremont Asinine Cunthead & total Moron "


Is it possible to bounce signals off the moon to other places on
earth? (i.e. use the moon as a comm satellite)


http://www.google.com.au/search?hl=en&q=moon+bounce+ham+radio+&btnG=Search&meta=

It's

called EME.



** It is called " moon bounce " by radio amateurs world wide and all
normal people.

EME is a merely a ham acronym used only by ASD fucked wankers.






...... Phil

isn't this what we call inappropriate?

 

[jasen]

On 2006-11-02, Bret Cahill <BretCahill@aol.com> wrote:

Would alternating a lot of capacitors and inductors in series
approximate a Slinky spring?

I think a slinky spring, being basically a coil, is mostly inductance :^)


If you're doing wave experiments with it however, it's a physical
delay line,

one way to make an electrical delay line is lots of inductors in series
and capacitors to ground.

--+-ww-+-ww-+-ww-+-ww-+-ww-+-ww-+-ww-+-ww-+-ww-+-ww-+-ww-+-ww-+--
| | | | | | | | | | | | |
=== === === === === === === === === === === === ===
| | | | | | | | | | | | |
--+----+----+----+----+----+----+----+----+----+----+----+----+--


Bye.
Jasen