can anyone help re: regulated lights

hi,can anyone tell me in reasonable detail how regulated lights such as sf a2 work? i have been looking at cpf for a while now and find the physics interesting(i used to be a radiographer). also while im at it what types of bulb give out most lumens-is it incan, led or something i havent heard of ? thanks.gc.

I think HID lights give out the most lumens per watt at higher levels. New led technology is approaching (surpassed?) the 100 lumens per watt level.

I'll give you an idea of how the A2 works. Normally, you have your flashlight and as I'm sure you've seen, as the batteries get weaker the beam gets dimmer and yellower, right? The batteries give as much as they can, and as they get weaker they just can't give as much.

The A2 is a unique light in that the incandescent bulb is regulated. Basically, the electronics inside the light keep the same amount of light going to the bulb no matter what, so you're not going to see a dimmer beam, no yellow, just plain bright light. Once there's not enough power left to keep that up with the A2, it switches to low power mode, which is a 3-LED ring around the bulb that will continue to run for quite some time. LEDs can also be regulated, as they can get dimmer too to some extent..