Chip with simple program for Toy

[colin]

<amremote@hotmail.com> wrote in message
news:1120304443.225111.39550@g14g2000cwa.googlegroups.com...

I should know how to do this, but please treat as a Newbie query

I have a simple circuit question for any analogue experts out there !
I'd be delighted if someone can suggest what I suspect is a simple
solution. I have no problem with digital circuitry, or making the
solution. My problem is a lack of understanding of analogue bits n
pieces and lack of time to learn due to work pressures


THE PROBLEM

- I have to link a very modern fuel-tank level probe to an old
fashioned car fuel gauge, via a simple circuit and it all runs of the
cars 12v supply.


THE DETAILS

- The supply rail will be typically 12-14vs
- The fuel probe is an expensive dedicated hyper modern capacitive
device with a pic chip type device in it. Once calibrated it generates
a high impedance output voltage of 0-5v linearly. Linearity isn't
important to me. It cant source more than a milliamp.
- The old fuel gauge is a fixed resistance 45ohm device with internal
mechanical damping. It isn't very linear but this isn't important.
The gauge reads empty to full with a voltage change across it of 0 -
10volts, and current consumption of 0-230ma or so.
- The 0 -> 5v input signal is pretty much a steady DC value so I cant
have a capacitor on the input as in a conventional simple amplifier
circuit.


THE QUESTION

- What simple FET based (or transistor!) circuit would link these two
devices ? Ideally I'd like someone to advise on a schematic, with
approx component values, that I can go off and build and tweak.


Help !! If you want to email me offlist use amremote at hotmail dot
com

Thanks in advance.
Andy / UK.

Simple circuit idea ..

+12v +---+-------+
| | |
| R=2k @=meter
opt=R | |
| | |C
| +-----| T2=any med power (to220) npn just simply bolted to
something metal
| T1| |E
22k| |E |
o--R-+--| R=6.8 ohm
| |C |
10k=R | | t1= any smal signal (high gain) pnp
| | |
-----+---+-------+

The 0-5v sensor voltage is divided by the 22k/10k to ~ 0-1.6v
This voltage then apears accros the 6.8 ohm resistor where it sets the
curent through T1 and hence the meter to ~ 0-230ma
T1 counteracts the vbe drop acros T2 and provides curent gain.

This should be moderatly acurate. bear in mind this is untested and at full
scale T2 is just about saturating, wich may mean 'full' scale is not quite
acheived depending on type of transistor.
ov input might not be quite zero current, this may corespond better to the
the guage anyway, the optional R is if you want to increase the curent on
empty. (try with 1meg)
you can always tweak it ie lower the 10k or the 6.8 ohm etc.

Colin =^.^=

 

[colin]

oops line wrap

+12v +---+-------+
| | |
| R=2k @=meter
opt=R | |
| | |C
| +-----| T2
| T1| |E
22k| |E |
o--R-+--| R=6.8 ohm
| |C |
10k=R | | t1= any smal signal (high gain) pnp
| | |
-----+---+-------+


T2=any med power (to220) npn just simply bolted to something metal (but
insulated!)


Colin =^.^=

 

[petrus bitbyter]

<mowhoong@hotmail.com> schreef in bericht
news:1120357947.603686.249280@g43g2000cwa.googlegroups.com...

I notice some fuse maker given voltage rating beside current rating
like 1 amp 250 volt & 1 amp 1000 volt, it make no diffrent on the
voltage as long any current reach more than 1 amp fuse will burn.
My explaination is correct ?

No. Once the fuse melts an arc arises which may not extingish fast enough
when the voltage is too high for the fuse at hand.

petrus bitbyter

 

[petrus bitbyter]

<mowhoong@hotmail.com> schreef in bericht
news:1120361418.770384.108250@g47g2000cwa.googlegroups.com...

I have few ac volt meter 0 to 30 volt, and i would like to buld
a car battery charger, can i just use one diode series on the
conection to convert the ac volt meter? Can any person help. thanks!

You can try to measure AC voltages using a DC meter this way. However, some
types of AC meters act on DC voltages as well. You can try out using a DV
voltage source and a series resistor - of let's say 10k - to stay on the
safe side.

petrus bitbyter

 

[Roger Johansson]

mowhoong@hotmail.com wrote:

I have few ac volt meter 0 to 30 volt, and i would like to buld
a car battery charger, can i just use one diode series on the
conection to convert the ac volt meter? Can any person help. thanks!

The first you should do is open one of the AC voltmeters, find out what
components there are inside. Chances are great that you can use part of
the circuit for DC, with some simple change.
There may be a capacitor to isolate for DC, and in that case you can
simply bypass with a short piece of wire to get a DC voltmeter.

As somebody said, try using the meter for DC, it may work directly.
Check the calibration of the scale in this case.

A more complicated alternative is to build a chopper which transforms a
DC voltage into AC so it can be amplified with AC amplifiers and
measured by an AC voltmeter.

A chopper has a measuring input prope which is quickly switched between
ground and the point to be measured.

This creates an AC signal with an amplitude equal to the voltage
difference between ground and the point of measurement.

The switches can be electronic switches or relays.

After the chopper stage, and optional AC amplifiers, we put the
rectifier, but your AC voltmeters probably already contain rectifiers.

Chopping is a way to measure very small DC voltages. The created AC
voltage has exactly the same amplitude as the DC voltage. It is then
easy to amplify the AC voltage. We have decided the frequency ourselves
and it doesn't change, so we can use tuned amplifiers to amplify the
signal by a certain number of decibels, or by a certain amplification
factor.


--
Roger J.

 

[Larry Brasfield]

"Will" <a7b98208@telus.net> wrote in message
news:3WJxe.104187$9A2.76887@edtnps89...

Hi Larry / the group,

Thank you for the reply.
You're welcome.

I've done some more experimenting with my commerical grade cable used with
the Alinco DJ-X10 wideband radio.

I've run a number of tests to using a standard 9-pin RS-232 cable (no
conversion) and measured/monitored the TXD and RXD lines on a dual channel
scope to serve as a reference.

As expected, RS-232 data lines idled in a marking state of -11V. Then using
a Windows Hyperterminal session @ 4800 bps, 8 data bits, 1 stop bit, set my
time base on my scope to reflect 208 us/DIV sweep so each bit duration
consume one graticule division. I then monitored the voltages on this line
as I held down and pressed various keys while observing their binary
equivalent on an ASCII chart. I observed 10 bits as expected (1 start bit,
8 data bits, 1 stop bit) and the levels behaved as I would expect.

I captured the screen shots of my scope for each of the characters I used.
I then hooked up my RS-232 / TTL conversion cable for the Alinco unit (not
actually connected to the radio ... hence "unloaded") and observed the
following:

1. No logical start or stop bits are observed.
2. On some keys, the binary codes produced predictable results, i.e. the
letter U which has alternate bits set (01010101). The TTL output was
comparable, but at ~ 3.5V.
3. TTL levels ranged from 0 to 3.5V unlike RS-232 levels (+/-11V)
4. Not all voltage sequences while monitoring the TXD TTL-level conductor
matched its corresponding bit sequence observed when using the RS-232 (non
conversion) cable.
5. As I recall the RS-232 standard (many years ago for me), the whole
concept of serial communicaitons was asynchronous in nature and hence each
byte was enveloped by a start and stop bit(s) to sync the tx'er and the
rx'er. However, on the TTL side, it appears as though there is no concept
of start and stop bits ( at least logically). Yes, I understand that
there's either 0 or 5V. That's it. But there is no asynchronous start/stop
bits utilized on the TTL side.
6. Since the TTL-side voltage transitions did not always correspond to the
RS-232 equivalent (ie voltage transition intervals), I am wondering if some
sort of encoding scheme is used (NRZ, NRZI, etc) ???

What should data in the RS-232 realm on pin 3 look like after being
converted into TTL level voltages? In some cases, the RS-232 logic level 1
(-11V) seemed to correspond to 0V in the TTL realm. In other cases, it
seemed to correspond to 5V. ?

I suggest you use a dual trace o'scope. I believe you will find,
if you trigger on one signal while looking at the other, (and do
not use the "alternating" display mode that analog o'scopes
usually have), that they have the same logical state at all times
except for the effects of propagation delay.

[snip]

PPS: Not sure I follow about the constant voltage level waiting a conductor.
Since the TTL signals seem to correspond in some relation to the originating
RS-232 data byte, the TTL level signal was only constant in voltage for the
duration of a bit, but it changed in magnitude (0 or 5V) accordingly.

You asked: "What is the industry convention when terminating the TTL side
of this cable to a stereo plug. ... is the tip conductor logic 1 or logic 0?"
The question makes little sense, so neither does the answer. What you
meant to ask may have made sense, but those words do not.

[Snip confusing top-posted stuff.]


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

 

[Mike]

Hi Larry / group,

You asked: "What is the industry convention when terminating the TTL side
of this cable to a stereo plug. ... is the tip conductor logic 1 or logic
0?"
The question makes little sense, so neither does the answer. What you
meant to ask may have made sense, but those words do not.

Actually, I see what you mean now re: the tip. I guess it was one of those
things where its clear in my mind but not properly captured on "paper". I
should have wrote: is the tip conductor TXD or RXD. My apologies. From
my testing so far, I have found that the tip is in fact RXD, thus ring is
TXD. Sorry for the confusion!

-W

 

[mike]

Will wrote:

Hi All,

I am interfacing a ham radio to a computer to program it and I have been
looking at various TTL / RS-232 conversion circuits. However I happen to
have a commercial ADMS programming cable I use with my Yaesu VX-7R radio
(ham radio). This cable also handles this type of conversion so I am
thinking why reinvent the wheel when I can utilize this existing circuit
which is already integrated into the D-sub shell of this cable.

Thus my question:

These generic circuits appear to RS-232 logic levels (+/-12VDC) on pins 2 &
3 of a DB9 connector and converts them to 0 & 5VDC. Which TTL voltage
corresponds to a logic 0 and which to a logic 1? On the RS-232 side, the
data pins use negative logic, so +3 to +12 VDC is logic 0 and -3 to -12VDC
is logic 1. Does the TTL data input use positive logic instead ( logic 1 is
+5VDC and logic 0 is 0VDC)?

What is the industry convention when terminating the TTL side of this cable
to a stereo plug. ... is the tip conductor logic 1 or logic 0? Once I
determine this, then I will use this existing conversion cable and simply
wire the stereo plug conductors to their respective TXD and RXD pins on my
Yaesu FT-857.

Lastly, what happens if one connects the TTL level TX conductor to the TXD
pin on the radio side accidentally instead of the RXD pin on the radio?
i.e. wires crossed in error

Thanks for any and all info!

73's Will

YMMV, 'cause there ain't no standard that everyone adheres to.
My experience has been that I can always make radio interfaces work
with inverting ttl translation.
I also use opto-isolators with appropriate reverse protection and
current limiting. Works for low data rates and helps with my paranoia
about smoking my laptop.
mike

--
Return address is VALID but some sites block emails
with links. Delete this sig when replying.
..
Wanted, PCMCIA SCSI Card for HP m820 CDRW.
FS 500MHz Tek DSOscilloscope TDS540 Make Offer
Wanted 12" LCD for Compaq Armada 7770MT.
Bunch of stuff For Sale and Wanted at the link below.
MAKE THE OBVIOUS CHANGES TO THE LINK
ht<removethis>tp://www.geocities.com/SiliconValley/Monitor/4710/

 

[Al Smith]

In spite of NASA's refusal to accept that the pressures resulting from
deep impact's impact on the comet being well beyond those found on the
sun, they've posted no warnings.

They assume that the comet is a rubble pile. As if there isn't any
potential of a comet impacting an meteorite, and producing a solid
core.

When a impact pressure produces a pressure in excess of that found only
on the sun, then the potential of a nuclear reaction involving
non-fissle isotopes becomes possible.

Unplug your computers transient protector from the wall but, do not
unplug your computer from the transient protector.

Hey, crazy conspiracy guy, you get points for originality. A
nuclear reaction! Neat. Impossible, but neat. But you forgot to
war people to put on tinfoil hats to protect their brains from the
pulse.

 

[Larry W. Jewell]

Some poeple never take their little tinfoil hats off, so they don't need
a reminder.

Al Smith wrote:

Hey, crazy conspiracy guy, you get points for originality. A nuclear
reaction! Neat. Impossible, but neat. But you forgot to war people to
put on tinfoil hats to protect their brains from the pulse.

 

[Bob]

"The Flavored Coffee Guy" <elgersmad@rock.com> wrote in message
news:1120437184.125114.297720@g14g2000cwa.googlegroups.com...

In spite of NASA's refusal to accept that the pressures resulting from
deep impact's impact on the comet being well beyond those found on the
sun, they've posted no warnings.

They assume that the comet is a rubble pile. As if there isn't any
potential of a comet impacting an meteorite, and producing a solid
core.

When a impact pressure produces a pressure in excess of that found only
on the sun, then the potential of a nuclear reaction involving
non-fissle isotopes becomes possible.

Unplug your computers transient protector from the wall but, do not
unplug your computer from the transient protector.

If the comet is a rubble pile, then only 4.5 tons of tnt will equal it,
and there will be no EMP pulse. If not, unguessable. I've done the
math, and if they hit a hard spot of sufficient mass, then the
pressures will exceed those found on the sun, where raw hydrogen is in
fusion and fision.

A nuclear reaction will generate an EMP pulse. But, that far away, and
the antenna that would recieve the full potential of that power isn't a
small box filled with components, like your computer. But, a birds
nest of wire like the power grid that leads to your house from the
power station.

Thanks for the heads-up, Chicken Little.

Bob

 

[Bob Eldred]

"The Flavored Coffee Guy" <elgersmad@rock.com> wrote in message
news:1120437184.125114.297720@g14g2000cwa.googlegroups.com...

In spite of NASA's refusal to accept that the pressures resulting from
deep impact's impact on the comet being well beyond those found on the
sun, they've posted no warnings.

They assume that the comet is a rubble pile. As if there isn't any
potential of a comet impacting an meteorite, and producing a solid
core.

When a impact pressure produces a pressure in excess of that found only
on the sun, then the potential of a nuclear reaction involving
non-fissle isotopes becomes possible.

Unplug your computers transient protector from the wall but, do not
unplug your computer from the transient protector.

If the comet is a rubble pile, then only 4.5 tons of tnt will equal it,
and there will be no EMP pulse. If not, unguessable. I've done the
math, and if they hit a hard spot of sufficient mass, then the
pressures will exceed those found on the sun, where raw hydrogen is in
fusion and fision.

A nuclear reaction will generate an EMP pulse. But, that far away, and
the antenna that would recieve the full potential of that power isn't a
small box filled with components, like your computer. But, a birds
nest of wire like the power grid that leads to your house from the
power station.

Better call Art Bell!

 

[Don Klipstein]

In article <1120437184.125114.297720@g14g2000cwa.googlegroups.com>, The
Flavored Coffee Guy wrote:

In spite of NASA's refusal to accept that the pressures resulting from
deep impact's impact on the comet being well beyond those found on the
sun, they've posted no warnings.

They assume that the comet is a rubble pile. As if there isn't any
potential of a comet impacting an meteorite, and producing a solid
core.

When a impact pressure produces a pressure in excess of that found only
on the sun, then the potential of a nuclear reaction involving
non-fissle isotopes becomes possible.

Well, the Sun has enough pressure in its core to compress 15 million
degree Kelvin hydrogen to over 10 times the density of lead. Even with
such pressure and such high temperature, only a few percent of the Sun's
hydrogen gets turned to helium every billion years.

Somehow, I don't see that kind of temperature and pressure occurring
during "Deep Impact".

Even if both the pressure and the temperature get that great during the
impact on the comet, I don't see any significant amount of nuclear
reaction occurring during the microsenconds that the pressure and
temperature are highest.

- Don Klipstein (don@misty.com)

 

[Don Klipstein]

In art. <slrndch6dj.mt7.don@manx.misty.com>, I, Don Klipstein wrote:

Well, the Sun has enough pressure in its core to compress 15 million
degree Kelvin hydrogen to over 10 times the density of lead. Even with
such pressure and such high temperature, only a few percent of the Sun's
hydrogen gets turned to helium every billion years.

Somehow, I don't see that kind of temperature and pressure occurring
during "Deep Impact".

Even if both the pressure and the temperature get that great during the
impact on the comet, I don't see any significant amount of nuclear
reaction occurring during the microsenconds that the pressure and
temperature are highest.

I add:

1. Consider that even if pressure and temperature get like that in the
core of the Sun (and it appears to me that most proposing that either, let
alone both of these can occur get suggested to wear tinfoil hats), the
amount of nuclear reaction would be miniscule compared to that in a
nuclear bomb. The Sun is expected to take about 10 billion years to fuse
most of the hydrogen that the Sun's core will fuse, and the highest pressure
of the impact will last what - a fraction of a millisecond? I don't see
anything like a nuclear bomb here even if both pressure and temperature
are like those in the core of the Sun.

Difference between the Sun and nuclear bombs:

Nuclear bombs with fusion reactions rely on especially fusible isotopes
of hydrogen (deuterium and tritium), along with temperature and pressure
never achieved by humans except by nuclear explosions.

Other reasons to not worry:

1. This is supposed to happen at a distance a bit over 220 million miles
or a bit over 350 million km from Earth. This is more than twice as far
away as the Sun is. I am unworried enough to be willing to leave my
computer and modem on and connected even if a nuclear bomb was scheduled
to be detonated directly above me at that distance.

2. If you are in the eastern or "midwest" USA or USA's "gulf coast" area,
or in Europe, the comet will be below the horizon at time of impact.
Radio waves that are not limited by "line of sight" do so by being
reflected or waveguided by frequency-selective regions of the Earth's
outer atmosphere.

- Don Klipstein (don@misty.com)

 

[Fred Garvin]

On 2005-07-03 20:33:04 -0400, "The Flavored Coffee Guy"
<elgersmad@rock.com> said:

In spite of NASA's refusal to accept that the pressures resulting from
deep impact's impact on the comet being well beyond those found on the
sun, they've posted no warnings.

They assume that the comet is a rubble pile. As if there isn't any
potential of a comet impacting an meteorite, and producing a solid
core...

Snip!


What kind of drugs are you on???


--
PCs, like air-conditioners, are useless when you open Windows.

 

[Fred Garvin]

On 2005-07-03 20:33:04 -0400, "The Flavored Coffee Guy"
<elgersmad@rock.com> said:

In spite of NASA's refusal to accept that the pressures resulting from
deep impact's impact on the comet being well beyond those found on the
sun, they've posted no warnings..

SNIP!

You have one an award. Go here to receive it:

http://www.strangecosmos.com/content/item/12342.html

--
PCs, like air-conditioners, are useless when you open Windows.

 

[The Caretaker]

The Flavored Coffee Guy wrote:

If the comet is a rubble pile, then only 4.5 tons of tnt will equal it,
and there will be no EMP pulse. If not, unguessable. I've done the
math, and if they hit a hard spot of sufficient mass, then the
pressures will exceed those found on the sun, where raw hydrogen is in
fusion and fision.

OK, if your theory is good, then you won't mind showing 'the math'
you've done so your peers might prove your theory to be sound.

Personally, I think you speak via your rectal orifice, but who am I to
judge?

--
The Caretaker .........

 

[Larry W. Jewell]

"almost"? Are you Bill Clinton? The flash was no where near as large as
the comet, and it's just an animation anyway, not a film. Reality show
come to your house for dinner once in a while.

The Flavored Coffee Guy wrote:

Okay, look at the flash. 4.5 tons tnt was their calculation. The
flash is shown to be almost the same diameter as the comet itself.
Kilotons.

http://www.nasa.gov/mission_pages/deepimpact/main/index.html

http://www.nasa.gov/mission_pages/deepimpact/images/Deep_Impact_Images_Search_Agent_archive_2.html

--
Contact me: larry w jewell @ hotmail . com (remove spaces, of course)

 

[Roger Johansson]

everymichael@msn.com wrote:

I am looking for advice. I need a varable control device that can
take standard 60 Hertz, 110 volts and give me a range from 15 Hertz
to 200 Hertz at 110 volts. This will be used to adjust the frequency
of pulsating light given from a fluorescent light bulb. Some people
find reading difficulty under fluorescent light. My theory is that
this may be related to a sensitivity to the frequency. I have a
basic knowledge of what needs to be done, but I am not sure what
components I need to purchase and how to put them together. Any help
will be appreciated!

What you need is basically what a music amplifier does.
It takes 110V and makes DC voltage which powers an amplifier which can
drive a loudspeaker.

Add a variable frequency generator and connect it to the input of the
amp.

If the output stage of the amp gives high enough voltage you can use it
as your new, variable frequency power supply.

I described this using an ordinary household item, an amplifier, to
explain what needs to be done in simple terms.

You may prefer to build an amplifier yourself, or buy one, but in any
case you need a power stage in the amp which can deliver the voltage
and current you need.

The variable frequency generator isn't too difficult to build, there
are schematics on the web.

One alternative I would consider is to use an ordinary amp with an
extra high voltage stage after it. Common amps for music seldom give
enough voltage to make 110V AC.

A transformer at the output of the amp is another possibility. If the
amp delivers +-30Volt the transformer takes it up to 110.
The size of this transformer and the power demands on the
amplifier depends on how much current you need.

By using a readymade amp I would save myself the most of the work,
building the transformer stage, rectifier and amp circuits.

Anyway, you you what you need now. A variable sinus wave oscillator, a
power amp, and maybe a transformer if the power amp isn't
specially made to produce high enough voltage by itself.

An output voltage checking and regulating circuit can be added, if you
need better regulation of the resulting AC output voltage than just
setting it manually using a voltmeter.


--
Roger J.

 

[Gerhard v d Berg]

"John" <look@sig.net> wrote in message
news:qcpbc1hreaaqeh0khanlmt0ufh468htehg@4ax.com...

On 30 Jun 2005 07:29:53 -0700, "Malcx" <mbailey@aethon.co.uk> wrote:

Hi all,


I've not dabled with any electronics since High school (about 10 years)
and have a fairly specific requirement for a detector that I want/need
to put together....

Background:
My storage tank leaked and ruined the flooring - the plumber couldnt
find anything obviously wrong with the tank but replaced the pieces
that showed signs of wear and we've had no obvious leakage since...

Now before the floor is re-laid I want to be doublly sure there no slow
leak going on...

As the storage tank gets warm, any surface (i.e. detectable) water will
evaporate pretty quickly while other moisture will seep out of sight
and do damage...

Specification:
I envisgae all being contained in a small box with probes coming out on
lengthy wires.

The box will have an LED that is permenantly on when the battery has
power (I'd envisage a 9v cell...)


Not a good idea, since the LED will run down the 9v battery very
quickly. You probably want an AC powered device, possibly with
battery backup.

Some CMOS logic chips or a low power version of the 555 timer chip can
be used for the latch circuit that stays on after being tripped.

The most basic wet/dry sensor is a piece of circuit board with the
copper foil divided in two parts. Board size is dependent on the
expected size of the wet/damp area (or the drip area, as appropriate).


There would need to be 2 or 3 moisture detection probes, when any 1
probe registers moisture another led on the box will be lit. This led
remains lit even after the probe dries. Only 1 led will be needed for
all of the probes - i.e. there does not need to be an led for each
probe.

A reset button will be required to reset the state of the device back
to "power led on only" mode.

(Ideally the sensitivity of the probes would be adjustable)

Can anyone help me with this seemingly simple circuit design? (I can
fit it all together, pcb design etc once I've the circuit diagram)

Thanks for your help in advance!

Mal

Have a look at this circuit
http://www.terrypin.dial.pipex.com/Images/DampDetector.gif
<Circuit checks "swamp-cooler" water level>
It is inexpensive and should work quite well. The piezo sounder output

volume is however a bit low with a 3 volt supply. The circuit will however

accommodate supplies up to 15volt. I would recommend a 6volt or 9volt

supply for better sensor sensitivity and operation (74HC93 or 74HC132

devices are however only spec ed for supply voltages up to 6 volt).



To accurately measure conductivity an AC voltage should be applied to a

sensor probe. In this simple moisture probe the current set-up should
suffice.

Advice by other members in the group on how to construct a moisture probe

might result in a good enough sensor for the job.



It would be better to have short leads for the probe and extend the

leads of the piezo sounder to locate it at a convenient site where it

would be noticed.



As a challenge add a latching circuit, with a manual reset, that beeps only

once a minute and a battery low detect Another 4093 and a simple

voltage detect circuit should be able to do it.



As for waking the girlfriend - add a kill switch to the piezo.

She should be pleased that your gadget managed to save the ceiling and
carpets .



GvdBerg