Repairing a TV remote control - new LED

Even at the same current, LEDs today give out far more light energy for the same current than LEDs of yesteryear, and they get better almost every year. It is an area of electronics to which a lot of time and research is being devoted. A modern LED can be glaringly bright and realistically used as a source of illumination at only 10mA, whereas years ago even driving one hard at 20mA or more would have had little more use than an indicator.

It is true that high power LEDs are available which are fed large currents, but that is another subject entirely.

Have a look here-.

Examples-

a true green 5mm LED tested at 26mA and gives out 14,340 mcd. a white 5mm LED tested at 19.28 mA that gives out 17,670 mcd.

There's a section on IR LEDs and one on UV LEDs as well, it's a fascinating site.

Dave

On Thu, 16 Feb 2006 11:30:15 -0000, "Dave D" Gave us:

Did not see ANY IR LEDs on the PURE ADVERT site.

Then you missed them, he reviews several. UV LEDs as well. Also lasers, flashlights and other lamps. I had no problem at all finding them. There's no need to shout just because you've had 'words' with other posters.

It's not an advert site, he gives often brutally honest reviews on all the products he tests. If something is crap, he says so in no uncertain terms..

Dave

Google seems to have no trouble finding IR LEDs ranging from 1.25 to 1.7 Vf (forward voltage drop). Look here:

scroll down to the IR LEDs and see how wrong you are about Vf on IR LEDs. Though I really don't understand how the 1.65 Vf LED can dissipate less power at 50mA than the 1.25 Vf LED does.

Just look at the "broad spectrum" of IR LEDs here:

Here's some high power LEDs: some more: Is that enough yet?

HTH, HAND

On Thu, 16 Feb 2006 13:37:23 -0000, "Dave D" Gave us:

I didn't shout. I feel it is stupid for the idiot running the site to call it a museum when he really means "collection of links to sites that will sell you something".

ALL CAPS throughout is shouting. Certain capitalized words IN a sentence is NOT.

So. He still carries NOTHING but links and pictures (banners) to other sites that want to sell you something, and that usually at overtly high prices.

Thanks anyway.

On Thu, 16 Feb 2006 14:48:49 GMT, "Anthony Fremont" Gave us:

1.25V to 1.7V. Imagine that! The same voltage that it has been at for decades.

You lose. Your original remarks were about finding one with a LOWER voltage drop than the norm.

Maybe you should research things before you spew something as if you are a pro, when all you seem to be is a google twit, and you didn't even get that right.

On Thu, 16 Feb 2006 14:48:49 GMT, "Anthony Fremont" Gave us:

More proof of your idiocy.

The power ratings they give are for output, not consumption.

The proof is that you can't even GET what you attempt to read.

No, my "original remarks" were about the OP finding one with a lower drop than the one currently installed.

Maybe you should read what is written rather than what you wanted to be written.

IR

So are you saying that the power out doesn't equal the power in? BTW, luminous intensity is never stated/measured in watts.

On Fri, 17 Feb 2006 00:43:55 GMT, "Anthony Fremont" Gave us:

Hahahah... Will you EVER know how stupid the remark you just made is?

NEVER? It appears that you don't know how to read the specs THEY POSTED, you retarded twit. EVERY produced energy has a wattage allegory.

The above statement still stands.

Here's a test, boy. Give an example of ANY device or transducer where the "power out" equals the "power in".

Maybe in your quest, you will actually get a clue.

Your remote was designed to use a particular IR LED on its output. If you were to put in a stronger LED design of the driver circuits for the LED would have to also be modified to be able to supply the new device. In the end, I would think this to not be feasible.

Also, there are most likely more efficient IR LED's around, but you would have to first work out the specs of the origional one, and then search out for an equivlent replacement that are more efficient. This may avoid any necessary modifications.

Considering that your TV and remote is very old, you should be considering a new system, rather than trying to modify it. In both the TV and remote, it is very probable that some of the components have drifted slightly out of specs over the years.

I have seen in some places that sell TV's and sound systems, a gadget that is called a remote control repeater. It is a unit that sees the IR from the user's remote control, and repeats it on its output. You only have to face the repeater in the direction where you want the IR beam to go. On the opposite side, it has a receiver for the user's remote. This also works very well under the proper conditions.

Overall consensus seems to be to leave it alone. Pity. Ok then I guess tha's the best option. Thanks to all.

Zak

Dont give up.

Advice such as "If you were to put in a stronger led..." and suchlike is mere gobblydegook.

The existing led has a peak wavelength of either 880 or 940nm. You need to get the right wavelength.

Then, to a first approximation, the efficacy (output) of all modern 5mm IR leds is pretty much the same from the major manufactureres. However the dispersion angle (2 theta 1/2) will greatly affect the range obtained - just like visible leds where a narrower angle makes the led 'brighter' on axis but dimmer away from the axis etc.

Yes modern IR leds are more efficacious that those of 15 years ago. Yes your old led will likely not be emitting anywhere near the power that it did when new - all leds, including IR leds, degrade with time. IR leds are generally bashed quite heavily and can show marked degradation with use. (The leds only degrade significantly with use).

Since current peaks are large put decent batteries in your remote.

*NOT* heavy duty marked batteries - this type of battery is not intended for significant current peaks - use high power alkalines..

My mother in law:

I tell her no (-1) and she replies YES ( +1)

Can't you discuss it rather then arguing about ?

I assume the 'need' for a brighter LED is because the remote doesn't work as well as remembered. CRT TV sets tend to get dirty. Has the IR sensor and protective plastic bezel been cleaned ? Just a thought...

GG