Pulsed light is claimed to have a greater apparent brightness for the same average energy. I guess the human eye acts as a peak detector. Oliver ----- Original Message ----- From: "Jinx" To: Sent: 21 January 2001 05:36 Subject: Re: [OT]: Overpowering LED's > > pulsing the LED with approx 80-100mA (according the the inline > > current sensor) and it is VERY bright and seems to be able to > > take it for quite a while(tested for 3 hours). Once I have 4 LED's > > on there though, I am actually drawing more power than the light > > bulb took. My main goal is to reduce power consumption in my > > car from as many spots as possible > > Hi, I hope I'm not going to put you wrong here and I remember > what was said. About a year ago there was a discussion about > illuminating a matrix of red LEDs by strobing. I think the general > agreement was that LEDs have a constant efficiency for converting > power to light. In other words, the amount of light produced is a > function of the average power supplied, whether this is by constant > DC or by a series of short high power pulses. If I've remembered > this correctly, then the conclusion is that to get a certain degree > of illumination, you have to put in a certain amount of power. Simply > shortening the length of pulses does not change the problem as > those pulses need to impart a high current. If you are using more > power than the light bulb, then in all probability you are producing > a lot more light. It may not appear so because it's not coming from > a point source like the bulb filament > > Pulsing LEDs IS a good idea for devices like infra-red transmitters > because the extra illumination caused by the short powerful pulses > can be detected at greater range than DC-driven LEDs. And as > above, strobing is used for matrices > > -- > http://www.piclist.com hint: To leave the PICList > mailto:piclist-unsubscribe-request@mitvma.mit.edu > > > -- http://www.piclist.com hint: To leave the PICList mailto:piclist-unsubscribe-request@mitvma.mit.edu