Sharp remote control ceramic resonator frequency?

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.

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

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

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:

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

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.

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

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:

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 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.

4 MHz is a nice number...

so is 3.58 MHz.

Mark

The DSE ESR meter uses 3.58MHz.... ;)

Bob

"Mark" wrote:

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:

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.