Controlling light output? PWM, or?...

[Cjarlif]

What´s the most suitable way of controlling the light output, for a canister dive light? I would like to control it by switching it on and off to adjust, let´s say between three different modes, like 10-50-100% light output.

I´m have pretty small mr16 head (typ:wreckhead) with 3 XP-Gs in serial, driven by a capsuled lead-acid battery. 12 V 2.2 Amp, and for now, driven by a buck, with PWM compability (solder pads for PWM input)

I´looking for a option that is, pretty simple or maybe not to complex anyway, fitting in a pipe with 30 mm Diameter.

I heard that the low.freq PWM have this disturbing "flickering" (I know that´s it´s actually flickering, but you know what I mean...)

Could it be an option to take the "mode" circusboard from any DXs circuit board and apply that to a bucket that is appropriate for the Voltage?

Please give me input or suggestions on what you think or what you are using yourself? What the options, PWM and...?

Thanks for all the help so far, and for a great forum!

/Carl

 

[plazma]

What buck driver do you have? It depends much of the driver. PWM is easy and the PWM frequency can be set high enough.

Analog power control may be more efficient but all drivers don't have that option. Also the color will shift more with an analog dimmer (at least in low power modes).

Full and 1/8 power option are enough IMHO.

 

[Cjarlif]

What buck driver do you have? It depends much of the driver. PWM is easy and the PWM frequency can be set high enough.

Analog power control may be more efficient but all drivers don't have that option. Also the color will shift more with an analog dimmer (at least in low power modes).

Full and 1/8 power option are enough IMHO.

I got a hole bunch of different drivers actually (some of them are still intact ), but the one I had in mind is BUCK Constant Current Power Supply (1000mA, 30V) @ led-tech dot de. But i´m thinkning of switch it in to a "PowerLine SLIM Constant Current Power Supply (1000mA, 30V)": ( I got this funny feeling it not okey to post links?!) But i´m have not come to a final decision on what driver to use, so is there an better alternative that´s suited PWM control more I will switch...


1/8 of would probably be good, but I´m thinking of those dives when it´s really murky water and you still wont a lot of light, but if you go full you will only end up in a cloud of light, that´s why I think 50 % or some what would be a great output also?! But my only reference her is with halogen, maybe LED dosen´t have that "murky water light cloud effect" where you see even less than with out the light

 

[plazma]

That SLIM model is not good. It's a linear model and wastes the voltage drop into heat. The battery voltage can be max. 4V over the led voltage.

 

[wquiles]

The best LED drivers that I have used are from www.taskled.com. You can email George (owner/designer) questions about your particular design goals, and he can recommend what would work best.

Will