Pulsed Led Ccs

Discussion in 'General Electronics Chat' started by haha11, Aug 29, 2014.

  1. haha11

    Thread Starter New Member

    Dec 10, 2008
    i have used a fast rise fall square waver transistor circuit to get the
    pulses like 30Hz
    one led shows the pulses

    SMd LED5050 x 2 PCS is the main lighting device
    for test purposes

    fed to the normal CCS (constant current source)

    * i came to know that LEDS can be pulsed with 2x or more current
    pulses like 100hz to 4Mhz are used in driver chips

    So made this amateure combo circuit .

    Question :
    I want to make the led take 150% current from rated 20mA ,
    is the combo working as pulsed oscillator

    Canwe avoid the CCS
    and safely pulse the LED with small changes

    is it good to pulse with 150% power for SMD 5050 leds
  2. ian field

    Distinguished Member

    Oct 27, 2012
    IIRC: Sharp have published some useful appnotes on pulse/duty cycle drive for LEDs
  3. haha11

    Thread Starter New Member

    Dec 10, 2008
    any links....for some specific info on SMD5050

    SMD 5050 led is good one procured from industrial supply
    today i pulsed them with 159mA current 2 modules in parallel

    they seem to light pretty bright..no heating for 20min test

    not sure if it may degrade life?