Toshiba TV29C90 problem; Image fades to black...

[Jim Adney]

On Fri, 24 Jun 2005 22:19:33 -0500 Jim Adney <jadney@vwtype3.org>
wrote:

On Fri, 24 Jun 2005 20:59:10 GMT Jonathan Kirwan
jkirwan@easystreet.com> wrote:

I had thought that maintaining an accumulated deviation of no greater
than 1/60 sec in 6 hours is about like 24 seconds/year or 2 seconds a
month. This is <1ppm drift. Without being temperature stable, this
is not so easy, is it?

It's about one part in 13 million, so, yes, this is pretty difficult.

Oops, I'm off by one decimal place; it's more like one part in 1.3
million. This can be done with a good crystal oscillator, but it's got
to be a pretty good one, and it has to be calibrated against a real
standard.

The question remains of why one would need this degree of accuracy in
a timing function.

-
-----------------------------------------------
Jim Adney jadney@vwtype3.org
Madison, WI 53711 USA
-----------------------------------------------

 

[James Waldby]

Searcher7@mail.con2.com wrote:

Mike Monett wrote:
Searcher7@mail.con2.com wrote:
.... and someone wrote
So, what degree of accuracy are you really needing?

1/60th of a second...

(ie: When the 2 hour, 53 minute, and 37 second point is reached, the
display should show it at exactly that time at an accuracy of 1/60th of
a second from when the clock started running).
....
You have no idea what your requirements mean. A drift of 1ppm in 6 hrs is
meaningless in a marathon or other race, when the wind can easily cause
1% change in performance.
....
I've been trying not to get into the details, because details lead to
the request for more details, and this is just way to complex to get
into here. Not just as far as what I'm doing, but the timer I am
seeking is actually inadequate for all of the experiments I want to do.

You will waste a lot less of everyone's time if you just go ahead
and explain what you want. If you happen to know. Of course if you
don't know what you want, you are less likely to get it.

Anyhow, AIUI you have a video game and you want to use a timer for
doing something related to this game ... perhaps you want to reverse
engineer it, perhaps crack some protection, perhaps set up a computer-
aided play device. Whatever. And you think that having a timer with
1/60 second accuracy displaying the current time throughout a six hour
period will help you do so. (It may be silly for you to think so, because
if you are just reading the time off the running display or pushing
buttons to record the time when stuff happens, you won't be able to do
either one with 1/60 second reaction times anyway.)

Note that the clock in the video game almost certainly will drift
around in a range at least 10 parts per million wide, which makes
your 1 ppm requirement superfluous. Instead, snoop the video game
clock and use a buffered copy of it to drive the counters in your timer.
This way your displayed time always is in sync with the video game time.

Now if this is so difficult to understand, then the more complex timer
will be near impossible to explain.

Perhaps your problem is that you don't know what you are doing.
Feel free to convince us otherwise.

For this project there will be 1,296,000 increments over the course of
6 hours. I just need the option of *visually* seeing on the timer's
display when each second increments beginning with the press of a start
button, and the accuracy must be 1/60th of a second at worst for any of
those 21,600 seconds after zero.

As several people have noted, you could use a TXCO (temperature
compensated crystal oscillator) or a crystal oven for adequate
performance. See eg $4 and $18 items
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=7526666127
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=7526612301

Note that you can get an inexpensive counter/timer on ebay, like
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=7526025102
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=7526108906
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=7526165454
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=7526085126
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=7526393893
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=7525744632
The bench instruments probably have 7 to 10 digit stability
when warmed up and similar accuracy when in cal. Some of them
might make their timebases externally available and/or have
totalizer functions that would do the job for you. In any case,
if you build a TXCO you'll need a counter/timer to check it.
-jiw

 

[Richard H.]

Searcher7@mail.con2.com wrote:

I've been trying not to get into the details, because details lead to
the request for more details, and this is just way to complex to get
into here.

Darren,

You are correct that it takes details to provide a useful answer. Based
on the broad question originally asked, the URL I provided should have
met your needs. Perhaps if we understood why you didn't find what you
needed there, more accurate responses might be possible.

If you work with engineers much, you'll appreciate that people very
often ask for the wrong thing - by challenging questionable requirements
the true specs become known, often hugely affecting the complexity
involved. Here, you are asking for a degree of accuracy that is
difficult to achieve, but you say you won't actually be using it, which
sounds flawed. (Irrespective of the event frequency in the DUT, if you
are only capturing one-second granularity, more accuracy is wasted.)

... the timer I am
seeking is actually inadequate for all of the experiments I want to do.

Now if this is so difficult to understand, then the more complex timer
will be near impossible to explain.

So, you're wasting everyone's time (including yours) looking for a
solution that won't meet your needs? If you really want nanosecond
accuracy, we can guide you to a solution that'd give you that, but not
if you don't ask.

If you would be less defensive about the requirements and share more
about your desired goal, you might get help in meeting it - the volume
of responses here demonstrates folks' willingness to help. We don't
need you to divulge your experiment, but significant requirements would
be nice (budget, size, weight, power, connectivity, inputs, outputs,
skillset), along with some tolerance for validating the potentially
difficult specs.


All that said, have you considered the overly simple solution of
software on a PC? It may be difficult to get better than 18.2ms
resolution from the system clock, but that is very close to your stated
requirement, and an RTC clock card would be easy enough to add.

Then, use SNTP to frequently check an atomic source and factor the drift
into the local clock's readings. (Or ditch the local clock entirely and
just make an SNTP/Daytime query of an atomic clock at the time you want
a reading - the accuracy can be calc'd as good as 1/250 sec.) Plus,
this is easily extensible to integrate with an event log, rather than
using a manual process.

Of course, there's no knowing if this will meet your other unstated
requirements, so perhaps it was a waste of time to share this idea?

Richard

 

[Gunner]

On 24 Jun 2005 13:01:09 -0700, "Too_Many_Tools"
<too_many_tools@yahoo.com> wrote:

I am crossposting this question since I think it will be of general
interest...sorry if that offends someone.

Now to the questions....what kinds of electronic and mechanical "trash"
is WORTH disassembling and keeping for parts to build other projects?

What did you keep that you should have thrown long ago?

What did you throw that you still kick yourself for tossing?

I look forward to your suggestions, experiences and jokes. ;&lt

TMT

Bring in an inventory crew and we can discuss mine.

Gunner

"Considering the events of recent years,
the world has a long way to go to regain
its credibility and reputation with the US."
unknown

 

In sci.electronics.repair Searcher7@mail.con2.com wrote:

The problem is what it is. There is nothing that can be changed.

If, even with expert help, a problem appears to be hard or expensive to
solve, change the problem. Every engineer has done that at least one but
probably several times...

---
Met vriendelijke groet,

Maarten Bakker.

 

[carl mciver]

"Too_Many_Tools" <too_many_tools@yahoo.com> wrote in message
news:1119643269.292995.117670@o13g2000cwo.googlegroups.com...
| I am crossposting this question since I think it will be of general
| interest...sorry if that offends someone.
|
| Now to the questions....what kinds of electronic and mechanical "trash"
| is WORTH disassembling and keeping for parts to build other projects?
|
| What did you keep that you should have thrown long ago?
|
| What did you throw that you still kick yourself for tossing?
|
| I look forward to your suggestions, experiences and jokes. ;&lt
|
| TMT

What on earth makes you think I can get all THAT in a BOX? Now that
space is becoming an issue, I'm having to start figuring out what I need to
get rid of. I'm keeping a lot of my car parts, regardless of how long I've
had them, 'cuz that make and model are history, but a lot of other stuff is
going. I've made two or three dump runs so far this year, so there's been
some progress.

 

[Gunner]

On Sat, 25 Jun 2005 02:37:50 GMT, "carl mciver"
<cmciver@mindspring.com> wrote:

"Too_Many_Tools" <too_many_tools@yahoo.com> wrote in message
news:1119643269.292995.117670@o13g2000cwo.googlegroups.com...
| I am crossposting this question since I think it will be of general
| interest...sorry if that offends someone.
|
| Now to the questions....what kinds of electronic and mechanical "trash"
| is WORTH disassembling and keeping for parts to build other projects?
|
| What did you keep that you should have thrown long ago?
|
| What did you throw that you still kick yourself for tossing?
|
| I look forward to your suggestions, experiences and jokes. ;&lt
|
| TMT

What on earth makes you think I can get all THAT in a BOX? Now that
space is becoming an issue, I'm having to start figuring out what I need to
get rid of. I'm keeping a lot of my car parts, regardless of how long I've
had them, 'cuz that make and model are history, but a lot of other stuff is
going. I've made two or three dump runs so far this year, so there's been
some progress.

I just brought home (tonite) 1000 lbs of mixed bar stock in 10'
joints. Lots of leadloy, a fair amount of 303, 316, 304, 17-4, 440C,
Brass, a few bits of bronze. Lots of tiny diameter "bars", most
..375-.5, some up to 3"

Screw machine company was scrapping all the stock they couldnt find
the certs for. Everything labeled..but no certs so it was unusable.

And they tossed in the material racks to go with it.

And by the good graces of Jerry M, who posts here, a scrapped pressure
washer that will be investigated in the morning to see if the pump is
good, then modified and reworked for here at the homestead.

Gunner

"Considering the events of recent years,
the world has a long way to go to regain
its credibility and reputation with the US."
unknown

 

[Mike Berger]

That's the correct way to do it. With the series connection
you have now, each TV down the line will get a progressively
worse signal. The star distribution configuration should give
you an adequate signal for each TV despite the longer coax length.

psistormyamato@cs.com wrote:

The 3 legs that I am running are far apart.
I could use 3 lenghts of 16 ft wire with 3 splitters or well over 150
ft of wire with a 5-way.

 

[pyotr filipivich]

Let the record show that Gunner <gunner@lightspeed.net> wrote back on Sun,
26 Jun 2005 06:48:42 GMT in rec.crafts.metalworking :

On Sat, 25 Jun 2005 05:31:57 GMT, Gunner <gunner@lightspeed.net
wrote:


And by the good graces of Jerry M, who posts here, a scrapped pressure
washer that will be investigated in the morning to see if the pump is
good, then modified and reworked for here at the homestead.

The pump is good, though tired <G

It is interesting how equipment which is too worn for commercial use is
still good for home use.
Knife makers in the Portland area used to snagg the "used" belts from
back of the Gerber plant, because what the Gerber workers considered
"shot", they considered, "a little worn".

tschus
pyotr

--
pyotr filipivich.
as an explaination for the decline in the US's tech edge, James
Niccol wrote "It used to be that the USA was pretty good at
producing stuff teenaged boys could lose a finger or two playing with."

 

[sofie]

Dom:
The high voltage power supply is not a separate part, it is integrated into
the main circuitry. Since you are an electronics tech you should be able to
perform some basic troubleshooting and testing to find the faulty components
and then replace them.
--
Best Regards,
Daniel Sofie
Electronics Supply & Repair
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -



"Dom" <dominickm@yahoo.com> wrote in message
news:1119883194.649500.92160@g49g2000cwa.googlegroups.com...

I have a Ford Super Duty and the radio display is not working. I've
been told that the high voltage power supply is the problem. I was also
told that this is a very common problem with this radio. Can someone
tell me where to get the part and how to repair it. I am a electronic
technician so I can do the repair myself with a little help from my
friends.

Please RVSP to me at dominickm@yahoo.com

Thanks in advance,
Dom Mauro

 

[Rich Grise]

On Sat, 25 Jun 2005 06:47:05 +0000, Mark Healey wrote:
....

Any bearing I can find (Where do I buy small numbers of bearings?)

http://www.mcmaster.com

Enter "bearings" in the search box.

Have Fun!
Rich

 

[John Fields]

On 27 Jun 2005 10:09:50 -0700, Searcher7@mail.con2.com wrote:

The problem is getting a timer.

---
I can build exactly what you want. Email me if you're interested with
how much you're prepared to spend to get it.

--
John Fields
Professional Circuit Designer

 

[NSM]

"JBreits" <jbreits@yahoo.com> wrote in message
news:1119883814.640663.319450@o13g2000cwo.googlegroups.com...

When heating up small amounts of cooked vegetables (i.e. 10-20 peas or
10-20 kernels of corn, small pieces of carrots, broccoli), I almost
always notice "sparking" in the food after about 5 sec. And if I
continue heating, it will actually produce flames usually in 10-13
seconds.

You have powdered metal in your food? Tried adding water?

Add a separate cup of water - not to the food.

N

 

[GS]

Howdy Dom......Without knowing the vintage or model number of the radio,
and without any initial troubleshooting info from you, there's little
except guessing left! If this happens to be say an early-mid 90's truck,
don't overlook the fact that many of those radios used a backlit LCD
display.....small #74 (if I recall) incandescent bulb (or whatever else you
can come up with .....these were typically a green looking digital display.

Gord

 

[jakdedert]

GS wrote:

Howdy Dom......Without knowing the vintage or model number of the
radio,
and without any initial troubleshooting info from you, there's little
except guessing left! If this happens to be say an early-mid 90's
truck, don't overlook the fact that many of those radios used a
backlit LCD display.....small #74 (if I recall) incandescent bulb (or
whatever else you can come up with .....these were typically a
green looking digital display.

Or maybe you have on polarized sunglasses. <G> That will make an lcd

display appear totally black from some angles.

This was actually a post from another newsgroup (today) about a technician
believe a piece of gear to have a bum display, when the only problem was
that had on a pair of the above....

jak
> Gord

 

[Cobalt]

ya, could be hard water...have seen old iron pipes that run underground make
the water hard because the rust gets into the water.

"NSM" <nowrite@to.me> wrote in message
news:7FZve.109962$on1.92810@clgrps13...
|
| "JBreits" <jbreits@yahoo.com> wrote in message
| news:1119883814.640663.319450@o13g2000cwo.googlegroups.com...
|
| > When heating up small amounts of cooked vegetables (i.e. 10-20 peas or
| > 10-20 kernels of corn, small pieces of carrots, broccoli), I almost
| > always notice "sparking" in the food after about 5 sec. And if I
| > continue heating, it will actually produce flames usually in 10-13
| > seconds.
|
| You have powdered metal in your food? Tried adding water?
|
| Add a separate cup of water - not to the food.
|
| N
|
|

 

[NSM]

"Cobalt" <spam@RS232.net> wrote in message
news:Z5mdnQ5K398BH13fRVn-tA@adelphia.com...

ya, could be hard water...have seen old iron pipes that run underground
make
the water hard because the rust gets into the water.

And slamming 1100 W into 10 kernels of dry corn isn't going to work either!

N

 

[darren]

on those TV's sometimes there is a HV ceramic capacitor that shorts
out ( right beside the H- output) however it usually has a visible
crack on it ( sometimes have to remove to see).. Hitachi TV's are
well known for flybacks to take out the H- output transistor, but can
be fairly expensive to "try it"

 

[darren]

my first thought is that is normal, I take it all is fine with a
regular amount of <food> ?

on side note, why you nuking 20 kernals of corn ?

 

[Arfa Daily]

When you say it does it on all 10 power levels, you are not seeing the
operation from the right viewpoint. You cannot control the output power of a
magnetron. It's either producing microwaves at full chat, or not at all. The
power setting is controlled by interupting the amount of time that the mag
is turned on for, so at 100% power, it's running all the time, at 50% power,
it's only running for half the time and so on. You will probably have heard
the transformer going KAWOMM as the mag cuts in and out.

This means that you are hitting those poor peas with 1100 watts of RF each
time the mag cuts in. Even if you are down on 10% power and you set the
timer for 1 minute, the 6 seconds that the mag would be on during that time
( probably three bursts of 2 seconds ), will probably be enough to make the
poor peas explode ...

The cup of water is a sound idea, as it provides a better load for the
magnetron. Very small quantities of food represent very little load, and
this can lead to rapid demise of the mag.

Geoff
"NSM" <nowrite@to.me> wrote in message
news:3m0we.110000$on1.93864@clgrps13...

"Cobalt" <spam@RS232.net> wrote in message
news:Z5mdnQ5K398BH13fRVn-tA@adelphia.com...

ya, could be hard water...have seen old iron pipes that run underground
make
the water hard because the rust gets into the water.

And slamming 1100 W into 10 kernels of dry corn isn't going to work
either!

N