Soft-start for mains LEDs?

[ardhuru]

Hello Everyone!

I have absolutely no experience in this, and had no idea where to begin; Google hasnt really made things clear(er).

I am looking for a readymade module (or, if not, designs, or ideas to make one) that would soft start an existing LED lamp. I'm talking about controlling an LED bulb, the kind that directly plugs into the mains (240v in my case).

Ideally, the soft-start should ramp up the lamp to full in about 5 seconds or so after switch on, although the ramp-up time isnt critical.

Does such a beast exist? Or doable??

Hoping the huge pool of talent on this forum would have some pointers!

Best Regards,

Anand

[mackrackit]

Use PWM and and ramp that up or down over a time period.

[ardhuru]

Dave, this is not an exposed LED; its one of those LED bulbs that directly replace an incandescent or CFL lamp in its mains holder.

[peterdeco1]

Hi Anand. I did this so long ago I forgot how. But I remember using a triac and diac configured as a lamp dimmer. It started as dim and gradually ramped up by charging a capacitor. I also remember one of my attempts blew everything up. Be careful. An exploding capacitor is like a firecracker with electrolyte inside.

[ardhuru]

Hi Peter, thanks for that information; now I know at least that its possible!

Do you have any tips at all, from whatever you can remember? Those would go a long way towards not re-inventing the wheel.

I'm familiar with triacs and phase control, as can be applied to incandescent bulbs, or resistive, or inductive loads. Its just that I cant figure out how to control something like these, to ramp up to full intensity spread over a few seconds. http://www.shopclues.com/philips-led...B&gclsrc=aw.ds

Regards,

Anand

[peterdeco1]

Sorry Anand. This was at least 20 years ago. All I remember is building a dimmer circuit and modifying the section that used the potentiometer to control the brightness. If I had to do it all over again, I would probably buy a dimmer and modify it. It's probably cheaper than buying all the parts and making it yourself.