Sharp remote control ceramic resonator frequency?

[Bob Parker]

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

 

[Mark]

Can you find the data sheet for the IC?

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

Mark

 

[Matt2 - Amstereo]

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

 

[Bob Parker]

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

 

[Bob Parker]

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

 

[Michael Black]

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

 

[Mark]

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

Mark

 

[Bob Parker]

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

 

[jakdedert]

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

 

[Frank]

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.




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

 

[N Cook]

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

 

[Bob Parker]

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

 

[Bob Parker]

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

 

[Terry Given]

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

 

[Bob Parker]

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

 

[Mark]

4 MHz is a nice number...

so is 3.58 MHz.

Mark

 

[Frank]

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




4 MHz is a nice number...

so is 3.58 MHz.

Mark

 

[Bob Parker]

The DSE ESR meter uses 3.58MHz....

Bob

 

[Michael A. Terrell]

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?

 

[Brian Goldsmith]

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.