remote control frequency

[Kurupt]

Does anyone know how to find the frequencies a remote control for a TV outputs. A buddy of mine told it can be calculated if I have the schematic. I don't have the schematic myself, I'm trying to help out my cousin, I have no idea what he's doing but he does have a schematic.

Any help is appreciated.

Thanks

 

[zachtheterrible]

You mean the IR remote? Usually it's 38khz. But sometimes it is different.

 

[Nigel Goodwin]

Does anyone know how to find the frequencies a remote control for a TV outputs. A buddy of mine told it can be calculated if I have the schematic.

I don't think your buddy knows what he's talking about :lol:

As already siggested, the IR modulation frequency is usually around 38KHz, this is almost universal.

But why would you want to know that?, it's stripped off and thrown away at the receiver, it doesn't carry any information, it's just a carrier frequency.

The remote control information is carried as digital information, using a number of different schemes, most of which bare no resemblance to any other. You can find details of the Sony SIRC's system in my PIC tutorials.

 

[mstechca]

the TV remote normally uses IR for data transmission. Frequency is unimportant, but you need a direct line of sight when dooing IR transmissions.

 

[JimB]

[quote="mstechca"} but you need a direct line of sight when dooing IR transmissions.[/quote]

Not completely true, IR will reflect off surfaces in just the same way as visible light.

JimB

 

[DigiTan]

That's true, my TV/VCR's receiver is sensitive enough to spot echos from the next room. Once I convinced a roommate it was an RF remote. :lol:

Kurupt, were you looking for the carrier frequency or something more like a bit rate?

 

[pljack]

I am working on a virtual IR decoder.
I would be very interested in other remote frequencies others have encountered.
I know 38Khz is very popular.
Any others?

 

[Nigel Goodwin]

I am working on a virtual IR decoder.
I would be very interested in other remote frequencies others have encountered.
I know 38Khz is very popular.
Any others?

Why bother?, just use an IR receiver IC, this produces the data you want, and NOT the carrier you don't. A 38KHz receiver IC will work for any IR remotes I've ever seen (with slightly reduced sensitivity for non-38KHz ones) - with the notable exception of very old B&O TV's, which used 100KHz for some silly reason?.

 

[pljack]

A 38KHz receiver IC will work for any IR remotes I've ever seen (with slightly reduced sensitivity for non-38KHz ones) [/quote]

Really?
So a 38KHZ will reliably read the 0's and 1's from a 32-40 kHz remote?
I will have to try that.

My original goal was to save a few dollars per unit by creating a virtual decoder.
But if the above is true it might be worth the few extra dollars.

Looks like I'm off to Radio Shark tonight.

 

[Nigel Goodwin]

Really?
So a 38KHZ will reliably read the 0's and 1's from a 32-40 kHz remote?
I will have to try that.

I only stock one type of IR receiver as a replacement for ALL sets, I've never had any problems with any set I've ever replaced one in.

In general though, 38KHz is by FAR the most popular one anyway!.