G'day,
I've been asked to help fix a Sharp CRMC-A310JBEO remote control
for an air conditioner. All that seems to be wrong is that it's been
dropped and the ceramic resonator's broken into tiny bits, making it
impossible to see what frequency was marked on it.
If someone can tell me what the resonator frequency is, I'll be
massively grateful!

Regards,
Bob

Can you find the data sheet for the IC?

The design probably uses the same as in the data sheet.

Mark

its probably a 455khz version E, these are found in analogue am radios
and any other ir remote control.

"Mark" wrote:

Can you find the data sheet for the IC?

The design probably uses the same as in the data sheet.

Mark

Thanks Mark,
I haven't removed the board... the resonator is mounted on the back
of it. I'll try that avenue if a 455kHz resonator doesn't work in it.

Bob

Matt2 - Amstereo amstereo@ToptusDOTcomDOTau wrote:

its probably a 455khz version E, these are found in analogue am radios
and any other ir remote control.

I've seen 455kHz resonators in remotes before, but I'm pretty sure
I've seen other frequencies too. Thanks for the suggestion. I'll give
it a try unless someone can positively tell me that it's another
frequency.


Bob

Bob Parker ) writes:
Matt2 - Amstereo amstereo@ToptusDOTcomDOTau wrote:

its probably a 455khz version E, these are found in analogue am radios
and any other ir remote control.

I've seen 455kHz resonators in remotes before, but I'm pretty sure
I've seen other frequencies too. Thanks for the suggestion. I'll give
it a try unless someone can positively tell me that it's another
frequency.

Yes, I have no idea what that one uses, but most definitely there
is not one frequency used for every remote.

Michael

another idea, connect a generator, adjust it until it works and pick
the closest standard value.

Mark

Thanks for the idea! Unfortunately the remote belongs to a
non-technical friend of an even less technical person (his landlord),
and that would have to be a last resort.

Regards,
Bob


"Mark" wrote:

another idea, connect a generator, adjust it until it works and pick
the closest standard value.

Mark

Michael Black wrote:
Bob Parker ) writes:
Matt2 - Amstereo amstereo@ToptusDOTcomDOTau wrote:

its probably a 455khz version E, these are found in analogue am
radios and any other ir remote control.

I've seen 455kHz resonators in remotes before, but I'm pretty sure
I've seen other frequencies too. Thanks for the suggestion. I'll give
it a try unless someone can positively tell me that it's another
frequency.

Yes, I have no idea what that one uses, but most definitely there
is not one frequency used for every remote.

Not one frequency, necessarily; but usually only a very few resonators. The
last time I had one which was (physically) broken, I pulled another from the
first nondescript remote I found in the junk box, and it worked fine.

Remember, many frequencies can be synthesized from one crystal. Try one out
of a junk remote and see if it works...can't hurt.

jak


Michael

I hate to sound like a silly tit, But have you rung Sharp and asked them ?

Sometimes you do get the jack pot strange as it might seem.




"Bob Parker" wrote in message
...
G'day,
I've been asked to help fix a Sharp CRMC-A310JBEO remote control
for an air conditioner. All that seems to be wrong is that it's been
dropped and the ceramic resonator's broken into tiny bits, making it
impossible to see what frequency was marked on it.
If someone can tell me what the resonator frequency is, I'll be
massively grateful!

Regards,
Bob

"Bob Parker" wrote in message
...
G'day,
I've been asked to help fix a Sharp CRMC-A310JBEO remote control
for an air conditioner. All that seems to be wrong is that it's been
dropped and the ceramic resonator's broken into tiny bits, making it
impossible to see what frequency was marked on it.
If someone can tell me what the resonator frequency is, I'll be
massively grateful!

Regards,
Bob

I would grab some salvaged resonators and try each in turn
300,400,455 and 500 would be the most common used.

Or try a medium frequency generator of a few volts pk-pk
fed into the resonator pads and see what effect on receiver with
different f settings

Diverse Devices, Southampton, England
electronic hints and repair briefs , schematics/manuals list on
http://home.graffiti.net/diverse

Howdy again,
It's easier to tap into the collective knowledge of all the
technical people on these two newsgroups, than try to get any sense
out of Sharp. So I thought I'd ask here before I followed up other
avenues.
Thanks to everyone for their suggestions. I'll tear apart a
Sharp TV remote I've got here, and try whatever frequency resonator's
in it first. If it don't work, I'll either contact Sharp or try other
frequencies.

Regards,
Bob


"Frank" wrote:

I hate to sound like a silly tit, But have you rung Sharp and asked them ?

Sometimes you do get the jack pot strange as it might seem.




"Bob Parker" wrote in message
.. .
G'day,
I've been asked to help fix a Sharp CRMC-A310JBEO remote control
for an air conditioner. All that seems to be wrong is that it's been
dropped and the ceramic resonator's broken into tiny bits, making it
impossible to see what frequency was marked on it.
If someone can tell me what the resonator frequency is, I'll be
massively grateful!

Regards,
Bob

Yesterday I started trying a few different resonators/crystals of
assorted frequencies in the remote. With a 455kHz resonator, the
output frequency to the IR LED was something over 4kHz, and all
functions were incredibly slow.
Figuring that the IR frequency should be close to 40kHz, I put in a
4MHz crystal, a frequency I'm sure I've often seen in remotes, and the
IR frequency was about what I thought it should be= just under 40kHz.
We're going to give this a try and see if it works.
Thanks again to everyone for their suggestions!

Bob


Matt2 - Amstereo amstereo@ToptusDOTcomDOTau wrote:

its probably a 455khz version E, these are found in analogue am radios
and any other ir remote control.

Bob Parker wrote:
Yesterday I started trying a few different resonators/crystals of
assorted frequencies in the remote. With a 455kHz resonator, the
output frequency to the IR LED was something over 4kHz, and all
functions were incredibly slow.
Figuring that the IR frequency should be close to 40kHz, I put in a
4MHz crystal, a frequency I'm sure I've often seen in remotes, and the
IR frequency was about what I thought it should be= just under 40kHz.
We're going to give this a try and see if it works.
Thanks again to everyone for their suggestions!

Bob

I fixed a friends remote last year, one leg of the 4MHz xtal had come
unsoldered.

Cheers
Terry

Terry Given wrote:

I fixed a friends remote last year, one leg of the 4MHz xtal had come
unsoldered.

Cheers
Terry

Thanks Terry,
I've seen the same thing happen. Now I know it wasn't my
imagination that I've seen 4MHz resonators in many remotes.
The remote still hasn't been given back to its owner, but I think
it will probably work OK now.


Cheers,
Bob

4 MHz is a nice number...

so is 3.58 MHz.

Mark

only because it (3.58 MHz.) is cheaper, and in the factory that matters a
lot.




"Mark" wrote in message
oups.com...
4 MHz is a nice number...

so is 3.58 MHz.

Mark

The DSE ESR meter uses 3.58MHz....

Bob


"Mark" wrote:

4 MHz is a nice number...

so is 3.58 MHz.

Mark

Bob Parker wrote:

The DSE ESR meter uses 3.58MHz....

Bob


Was that because you had plenty on hand, or was it recommended for
the microprocessor you selected?

--
?

Michael A. Terrell
Central Florida

"Michael A. Terrell" wrote


Bob Parker wrote:

The DSE ESR meter uses 3.58MHz....

Bob


Was that because you had plenty on hand, or was it recommended for
the microprocessor you selected?



**** As 3.579545 MHz is the NTSC colour burst frequency,there are millions
of these crystals around the world.Because of availibility and low cost,they
get used in all sorts of circuits.

Brian Goldsmith.

"Brian Goldsmith" ) writes:
"Michael A. Terrell" wrote


Bob Parker wrote:

The DSE ESR meter uses 3.58MHz....

Bob


Was that because you had plenty on hand, or was it recommended for
the microprocessor you selected?



**** As 3.579545 MHz is the NTSC colour burst frequency,there are millions
of these crystals around the world.Because of availibility and low cost,they
get used in all sorts of circuits.

Brian Goldsmith.

But if it was recommended, chances are good that it was because they
are common. If there's no need for a specific frequency (because the
crystal isn't being used to supply something else that does need it)
one might as well go with a cheap crystal in the general range desired.

Michael

Brian Goldsmith wrote:

"Michael A. Terrell" wrote

Bob Parker wrote:

The DSE ESR meter uses 3.58MHz....

Bob

Was that because you had plenty on hand, or was it recommended for
the microprocessor you selected?

**** As 3.579545 MHz is the NTSC colour burst frequency,there are millions
of these crystals around the world.Because of availibility and low cost,they
get used in all sorts of circuits.

Brian Goldsmith.


Gee, Brian, I've known this since the mid '60s. I have a few oddball
color burst crystals, including an early Zenith one in a glass envelope
like a miniature TV tube. I am disabled, but I have worked as a
broadcast engineer at three TV stations. I guess you didn't see the
winking smiley?

--
?

Michael A. Terrell
Central Florida

Hi Brian,
Everyone else answered your question for me! As they said, NTSC
colorburst crystals are very common and very cheap. The firmware in
the micro doesn't need a higher clock frequency than that, so that's
why I chose it.
The micro internally divides the 3.58MHz by 8950 (179 x 50) to
produce a 400Hz reference for all its timing. It worked out pretty
well.

Regards,
Bob



"Brian Goldsmith" wrote:


"Michael A. Terrell" wrote


Bob Parker wrote:

The DSE ESR meter uses 3.58MHz....

Bob


Was that because you had plenty on hand, or was it recommended for
the microprocessor you selected?



**** As 3.579545 MHz is the NTSC colour burst frequency,there are millions
of these crystals around the world.Because of availibility and low cost,they
get used in all sorts of circuits.

Brian Goldsmith.

Oooops, I was replying to Michael not Brian!

Bob



Bob Parker wrote:

Hi Brian,
Everyone else answered your question for me! As they said, NTSC
colorburst crystals are very common and very cheap. The firmware in
the micro doesn't need a higher clock frequency than that, so that's
why I chose it.
The micro internally divides the 3.58MHz by 8950 (179 x 50) to
produce a 400Hz reference for all its timing. It worked out pretty
well.

Regards,
Bob



"Brian Goldsmith" wrote:


"Michael A. Terrell" wrote


Bob Parker wrote:

The DSE ESR meter uses 3.58MHz....

Bob


Was that because you had plenty on hand, or was it recommended for
the microprocessor you selected?



**** As 3.579545 MHz is the NTSC colour burst frequency,there are millions
of these crystals around the world.Because of availibility and low cost,they
get used in all sorts of circuits.

Brian Goldsmith.

Bob Parker wrote:

Oooops, I was replying to Michael not Brian!

Bob


How are you doing these days, Bob?

--
?

Michael A. Terrell
Central Florida

Hi Michael,
I'm pretty busy now. I've done what I told everyone I'd never do
again = working for someone else, designing circuitry for engine
control computers (or trying to).
How's things down in 'gator-filled Florida these days? Maybe we
should continue this by e-mail...?

Regards,
Bob


"Michael A. Terrell" wrote:

Bob Parker wrote:

Oooops, I was replying to Michael not Brian!

Bob


How are you doing these days, Bob?

Ahhh go and visit him Bob. If you still have all that hardware in your
leg the gators 'll only break their teeth

David

Bob Parker wrote:

How's things down in 'gator-filled Florida these days?

G'day David,
You sure do pop up at the least expected times!
(1) Florida's further from Sydney than you might realize.
(2) There are only 2 screws in my leg now, so I wouldn't trust that to
protect me from 'gators. Do you realize that believe it or not, it's
30 years ago in just over a month from now, that they put all that
stuff in my leg? Where does the time go???

Bob


quietguy wrote:

Ahhh go and visit him Bob. If you still have all that hardware in your
leg the gators 'll only break their teeth

David

Bob Parker wrote:

How's things down in 'gator-filled Florida these days?

quietguy wrote:

Ahhh go and visit him Bob. If you still have all that hardware in your
leg the gators 'll only break their teeth


You would be surprised what a gator can bite through. I've seen cars
on the Orlando TV stations where a gator bit a chunk out of a car or
pickup truck. One man left his tailgate down on his truck and had a
gator in the truck bed the next morning. he had to wait for the state
to send a licensed trapper to remove it and take it to the Everglades to
release it.


David

Bob Parker wrote:

How's things down in 'gator-filled Florida these days?


Not many gators in Marion County, but there were plenty about 30
miles south of here at my old house in Lake County. It was a common
sight to to see a gator run across the yard heading to or from the marsh
behind my workshop.

I'd like to meet Bob. I think he's almost as crazy as me!

--
?

Michael A. Terrell
Central Florida

He's a great bloke to work with - good tech and laugh a minute. But if the
bugger ever offers you a cup of coffee be sure to check the inside of the
mug handle - you never know what you might find there

David

"Michael A. Terrell" wrote:


I'd like to meet Bob. I think he's almost as crazy as me!

quietguy wrote:

He's a great bloke to work with - good tech and laugh a minute. But if the
bugger ever offers you a cup of coffee be sure to check the inside of the
mug handle - you never know what you might find there

David


No problem! I don't drink coffee. I've talked to him by e-mail for
several years and I think he's an OK guy.

Maybe I should send him a small gator to fatten up for Phil?

--
?

Michael A. Terrell
Central Florida

Hey, fair go. We have animal cruelty laws here you know :-)

David

"Michael A. Terrell" wrote:

Maybe I should send him a small gator to fatten up for Phil?

--
?

Michael A. Terrell
Central Florida

Now David, you know that I would *never* stoop so low as to play
practical jokes on anyone!! Thanks for telling nice lies about me,
though.

Bob


quietguy wrote:

He's a great bloke to work with - good tech and laugh a minute. But if the
bugger ever offers you a cup of coffee be sure to check the inside of the
mug handle - you never know what you might find there

David

"Michael A. Terrell" wrote:


I'd like to meet Bob. I think he's almost as crazy as me!

Bob Parker wrote:

Now David, you know that I would *never* stoop so low as to play
practical jokes on anyone!! Thanks for telling nice lies about me,
though.

Bob


How about "Impractical jokes"?


--
?

Michael A. Terrell
Central Florida

quietguy wrote:

Hey, fair go. We have animal cruelty laws here you know :-)

David


It wouldn't work anyway. The gator would get one taste and spit him
out.

--
?

Michael A. Terrell
Central Florida

Hey Bob, send me a $1.33 in used notes and I'll keep quiet

David

Bob Parker wrote:

Now David, you know that I would *never* stoop so low as to play
practical jokes on anyone!! Thanks for telling nice lies about me,
though.

Bob

quietguy wrote:

He's a great bloke to work with - good tech and laugh a minute. But if the
bugger ever offers you a cup of coffee be sure to check the inside of the
mug handle - you never know what you might find there

David

"Michael A. Terrell" wrote:


I'd like to meet Bob. I think he's almost as crazy as me!

quietguy wrote:

Hey Bob, send me a $1.33 in used notes and I'll keep quiet

David

OK, I'll do that!
Or maybe I could tell them about the time you got someone to hang
onto the exposed ends of the wires coming out of a plug you inserted
into the 240V power outlet, and were about to throw the switch....?
Now that is something I'll never ever forget!

Bob

The look on your face as I hit the power switch was priceless - and when
the apprentice (who was holding those leads) hit the floor I thought you
were going to freak out!

David

Bob Parker wrote:

OK, I'll do that!
Or maybe I could tell them about the time you got someone to hang
onto the exposed ends of the wires coming out of a plug you inserted
into the 240V power outlet, and were about to throw the switch....?
Now that is something I'll never ever forget!

Bob

Ahhh, now you understand the motivation for some person (not further
described) sabotaging your coffee mug!!

Bob

quietguy wrote:

The look on your face as I hit the power switch was priceless - and when
the apprentice (who was holding those leads) hit the floor I thought you
were going to freak out!

David

So what frequency was it after all?
Mark