Kevin,

e044730 wrote:

 

Brian,

I am looking for surface mount LEDs that operate at 200deg C.  Do you know of any?

 

Kevin

The survivable junction temperature for an LED die is 125deg C.  Anything beyond this temperature starts to delaminate the junction and the LED will cease to function as intended.  It is extremely unlikely for a solution to be found unless the technology of LED lighting changes.

dear sir,

I required LED leghting design, LED constant current controll circuit

Please guide me

Brian

I have an RV which has 12V lighting. The fixtures use clear tail light bulbe and they draw lots of current and don't last very long. I have been trying to find a suitable led that works. No luck to date. I think I need cree leds perhabl 2 or 3 emitters and pointed parallel to the mount axis. They should have an emit angle of approx 120 degrees. Do you know of such an animal?

Thanks

Val

John,

Your best bet is to find pre-made lamp replacement devices.  These have the necessary components internally to allow the LEDs to operate at the necessary voltage levels in certain applications, 12V being yours.

Fortunately, 12V DC applications are the simplest and easy to deal with on your own.  They simply require only a resistor in addition to the LEDs and the packaging.  The simplest case is 3 LEDs in parallel -> resistor -> 12v power.

The harder part is finding an emitter that has enough brightness and a wide enough view angle to fit your needs. Another consideration is how much power is available from the 12V source.  There are some very powerful emitters out there these days.  These emitters, in the LED world, are referred to has high powered.  This is a bit of a misnomer because LEDs are still lower power when compared to incandescent bulbs.  These emitters go from 1W (3V@350mA) to as high as 10W in some cases.  These high power emitters do need some form of thermal management in order to not fail early though.  You can find examples of these products here and here.

Best regards,

Brian

Thanks for the info Brian. My RV has over 400 amp hour of battery available to the house. We have a genset to replace what is used so available DC isnt the issue. I am trying to lessen the load and provide better light while extending the service life of the bulb. All possible with the hipower led's. My lamp fixtures are 1156 bases and are fairly deep (a[[rox 1.5") inside the shade. I have purchased single samples of bulbs with multiple emitters in the end with unacceptible results. Same goes for those lights with emmitters built up along the long axis of the bulb. I had hoped that you would be a fount that steered me to a solution. In the meantime I have purchased a gender changer 1156 to parallel pins and samples of hipower bulbs to try. This is, of course, a lot of trouble for only 12 fixtures, but one I think worth the effort as in our previous home one night with the outside entryway light left on flatted one deep cycle battery with 90 ah capacity. Dont want this with this coach.

Dear Sirs

I would like to use AM OLED colour display 240x320-2.8" in a new design, like for instance Densintron C0283QGLD-T. As far as I now, the said displays are not in production at present. My question is whether thise displays will be available in future or if they are to be replaced with any other similar AM OLED display. What are perspectives for availability of the AM OLED colour displays?

Awaiting your reply

Kind regards

Jacek Barański

Jacek,

AM OLED modules are still quite an immature technology.  They are more widely available today than they were even a year ago, but there is a lot of work still to be done to improve the lifetime.  Certain colors on the OLED still get under 10k hours.  It does not surprise me that you are having trouble getting some for your design.  There are some manufacturers out there that may be able to help you, but you need to be aware of the risks to make sure that it is sensible to fit one into your design, especially when TFT alternatives at that size are so cost effective in comparison.

I hope this answers your questions.

Best regards,

Brian

Hi,

I am looking for a way to mount near infra red power LEDs into surfaces such a way that they could directed after the mounting. The LED we are looking to use:

http://www.epigap-berlin.com/uploads/tx_mvmdprodukte/ELJ-870-629_03.pdf

We are going to install these LEDs into outside environment as marking LEDs for near infra red cameras, one LED every 1 meter or so.

The viewing angle of such led is quite small (approx 17 deg), and we would need to find a robust way to adjust the direction of the lens (left, right, up, down) up to 60 degrees from the mounting position to all directions. Is there a ready made "collar" that cold be used? Any ideas where to look for such LED mounting? Or any other way to direct the beam?

Thanks in advance,

Vesa