Your thoughts for the ideal on-camera LED

In a general way, can you explain what is the alternative to PWM for dimming LEDs? I've done a lot of digital circuit design with small displays and such, not high power LEDs used for illumination, and all my teachers ever taught me was how to do PWM to control brightness (without throwing away energy in a current limiting resistor or whatever). (You can get somewhat technical in your answer, I've got the general electronics experience, just not in this specific area.) Thanks.

- GDS
 
Any idea when you will be ready to release these camera LED lights? Also, your thought about making an LED light that had equiv output to a 1k.. well.. that would be awesome.
 
The 1K is just a thought at this moment, however the possibility of such a light possible with the present components available. The leds, driver (s) optics/reflectors and the chassis are all to be carefully considered before any design and prototyping begins. The 1K unit's overall size/shape and flexibility is dictated by the intended use of the product along with surveys on just what is required by videographers. I would like at this time to concentrate more on the much needed on-camera light that is on it's final phase to completion. I have also been asked if there will be on the on-camera unit the option of having a 2 or 3 different angle of beam spreads say a spot of 10 degrees for hair light or distance throw, a mid-range of around 30 degrees for fill light and a 75 degree flood for large area coverage. That will most likely be made before the 1K unit is even thought about as the chassis is already done. If I had to give you a slight peek into the 1K, and this is just at the top of my head, it would be a compact unit of 9 in.X 9 in X 4 in. using 40 power leds , 20 warm and 20 cool, to output 3200K, 4300K and 5500K on demand. Drawing less than 200 watts and somehow able to be powered up from 2 -14.4V 90W/H ENG type bricks for a full power duration of around 45 minutes ( more with higher cap. batteries). Of course, as leds go, dim it down just a wee bit and gain big time on run time. It can be possible, not a matter of if, but when. Interesting times indeed.
 
PWM dimming scenario is a pulsed timing design that really varies the "on cycle frequency/duration" of the feed current to the led(s)..from what I have been told. There are many write-ups on the web explaining more and in better detail than I can about this subject. I have heard of harrowing tales that a PWM circuit ( on a led light) close to the camera's microphone caused a high pitched whining sound to be recorded along with the regular audio.A linear regulator from what I gather is the one that dumps unneeded power (energy) to be dissipitated via a resistor when dimming is in use. The ideal driver or led current controller is the one in my opinion that has a constant current output design WITHOUT any pulsing or energy dumping. The dimming is really varying the smooth (not pulsed) current through the leds. This type of driver can accept a wide input DC voltage range, have reverse polarity protection ( so the lamp will not go "poof !" with a billow of smoke and a smell of burning rubber if the input wiring is accidentely reversed, and also have a thermal protection heat cut-off in case you decide to use the lamp on full power in an atmosphere where ambient temperatures are really high.In the thermal protection shutdown case, one just waits a few minutes for the driver to self re-set and fire up again but at a lower dimmed level to continue the shoot.I have decided to go with this design on the driver. The led driver is really what makes or breaks a good led light, as all of the input power has to go through it before it gets to the leds, driver efficiency can be as bad as losing over 30% of input power or as good as just losing under 10%. No driver is 100% efficient.
 
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