Results 1 to 10 of 11

Thread: why GHL take 200Hz PWM on LX7206

Hybrid View

Previous Post Previous Post   Next Post Next Post
  1. #1
    Join Date
    25.08.2018
    Posts
    18

    Frage why GHL take 200Hz PWM on LX7206

    200Hz PWM is too low frequency, you can easily capture by your phone when taking slow motion or video.

    I can understand the huge power dissipation of 72 diodes. But I think the big heat sinker + 3 fans, which should be enough for maximum power. In case overheating, you have complete safe protection of LED diodes.

    meanwhile, I am questioning PWM. No sure the negative impact to fish or corals. Because nature lights, has no such PWM regulation.
    If compare with US competitors, none of them take such low PWM frequency. All of them are using much higher frequency, e.g. 100KHz. It will be no impact to the photograph video taking.

    Can you consider to improve this in next firmware upgrade?

    PS, I know you provide the photo mode in GCC. But can you introduce on touch panel or GHL connect for quick access.
    Thanks.

  2. #2
    Join Date
    25.08.2018
    Posts
    18

    Default

    the real filed test is only 150Hz. Still wondering why GHL engineer take so low value, which already can be captured by smart phone camera.
    If purely for energy saving, I disagree it. Because you can keep the PWM, but increase the frequency, e.g. 1KHz? The only possible reason is the limitation of MCU computing power, difficult to manage 12 driving channel in parallel.

    Any one can clarify here?
    Thanks.

  3. #3
    Join Date
    13.08.2010
    Posts
    4,150

    Default

    200HZ for corals and fish a problem??? 50-60HZ HQI /T5/T8 or other no problem???
    What do fish be interested what you see with your smartphone?

    For a detailed opinion you will probably have to wait for some information from GHL.

    regards pit

  4. #4
    Join Date
    25.08.2018
    Posts
    18

    Default

    for long term, I think it matters.
    The artificial lights always try to mimic the natural sun light. I think these ocean creature will never experience this pwm lighting in their life, except in our aquarium tank.

    Meanwhile, taking the comparison from GHL major U.S. competitors, most of them use much much high PWM frequency to reduce the light flicking.
    So I would like to understand why GHL take this choice.

    Anyway, I love my 4 GHL LX7206, almost perfect LED lights on the market. If GHL can fix this drawback further, it will become truly unbeatable.

  5. #5
    Join Date
    13.08.2010
    Posts
    4,150

    Default

    The sunlight should be around 600THz, which means
    600,000,000,000,000 kHz. And you think you can get near the sunlight with 100KHz or more.
    For me, it's pure marketing, what brings more problems than advantages. Which of course doesn't mean that GHL can't optimize anything. But this is not done with a firmware update.

    regards Pit

  6. #6
    Join Date
    25.08.2018
    Posts
    18

    Default

    Thanks for your reply.

    GHL used a very powerful microcontroller in LX7206, CYPRESS, MB9B500B series, which is 32-bit ARM cortext M3 core, 80MHz operation frequency.
    I guess GHL use GPIO to toggling the PWM signal for each channel. So by increasing this PWM frequency, it should be feasible to realize by upgrading the firmware.

    Hoping this post can be passed to GHL engineer and may feedback on this.
    Thanks.

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •