How can I make a scanner led light using 1,25 V X 0.054 ma (VIMUN SC - 3012) ?

Discussion in 'Power Electronics' started by sciencetoolbar, Nov 21, 2018.

  1. Hypatia's Protege

    Distinguished Member

    Mar 1, 2015
    DOH! Got it!:oops: PCB P/N= HT111A1 --- I'll see what I can find:)

    Best regards
  2. wayneh


    Sep 9, 2010
    Before you go too far down this path I suggest testing what your LED looks like when supplied your full budget of energy, 60 microwatts or whatever. You cannot expect your machine to do any better and in fact it’s probably losing half or more of the energy. You’re only getting flashes now because your machine - by design- feeds the LED a very low duty cycle, perhaps 1% or less. If you try to achieve a higher duty cycle, you’ll smooth out the pulses to a very dim glow.

    I don’t see how the filter cap on the LED can be helping. Removing it entirely might help?
    shortbus and Hypatia's Protege like this.
  3. ebp

    Well-Known Member

    Feb 8, 2018
    filter cap on LED

    I quit following this thread days ago, but if what is being talked about is a capacitor directly across a LED, on its own it will do nothing to increase the energy delivered to the LED. A LED has no negative resistance characteristic, therefore energy stored in the capacitor is simply energy not available to the LED. You might get a tiny effect because of the negative temperature coefficient of forward voltage of the LED.

    Properly used, an inductor can discharge all of its stored energy into a LED.
    Hypatia's Protege and shortbus like this.
  4. Hypatia's Protege

    Distinguished Member

    Mar 1, 2015
    FWIW it is my understanding that the TS is endeavoring to intermittently illuminate ('flash') the LED via energy 'stored' in the angular momentum of the 'rotor' -- Granting the gross inefficiency inherent to such a 'mechanical reactor' arrangement, it must be confessed that 'moving parts' make for winsome novelties (which being the TS' stated application of the device):cool:

    True enough! -- Though I daresay (series connection of) a low E[bo] Diac would help that:)

    Best regards