Re: Tech: TZ Color Changing LED (Clock Millions)

I didn't see this update until now.

If I had this problem, I would put a scope probe on the LED to see
what is happening.

If it is a brief col/row overlap, I would put a small capacitor in
parallel with the LED. The size would depend on the overlap. If
there is a leakage in a drive transistor, I would put a parallel
resistor to bleed it off.

Edward Cheung CARGPB26

On Feb 9, 4:29 pm, Mike Muglia <mikemug...@xxxxxxxxxxx> wrote:
On Feb 9, 10:18 am, martin <martin.reyno...@xxxxxxxxx> wrote:



On Feb 9, 3:47 am, beaver <e...@xxxxxxxxxxxx> wrote:

I am quite sure this kind of subject has come up in recent weeks.
When using LEDs, it was previously reported that lamps that are
supposed to be off are lit dimly.

I think it may be possible to filter this with a capacitor across the
LED, but I have not thought much about it.

Edward Cheung CARGPB26

On Feb 9, 12:22 am, Chris LeMasters <clemast...@xxxxxxxxx> wrote:

I purchases one of the color changing LED lamps (#44 replacement) for
the "Clock Millions" target on my TZ. The lamp works fine (and looks
quite impressive, too), but now I get an unusual behavior. Whenever
the "Middle Right 5 Million" lamp is activated, the "Clock Millions"
LED lamp also lights, although much more dimly than normal. If I
replace the LED with a normal #44, the power must not be enough to
cause this behavior.

The "Middle Right 5 Million" lamp is right next to "Clock Millions" on
row 2.

Is a bit of 'power leak' typical in adjacent lamps on the same row -
and could it be enough to trigger the LED but not a regular lamp? (I
thought it normally worked the other way).

I thought this was interesting. Any thoughts? Anyone else try this
LED and have a similar experience?

Chris LeMasters
San Diego- Hide quoted text -

- Show quoted text -

My thinking is that the WPC system has overlap when changing the row
and column drives. The drive lines are always on, so that when the
switch matrix changes columns, there is overlap for a little window.
That is enough energy to make the LEDs flicker.- Hide quoted text -

- Show quoted text -

I guess at this point, the big question is how do we stop it from
happening, and is there a fix?

Mike

.

Relevant Pages

  • Re: DynoHubs: What light bulbs/LED emitters?
    ... I'm assuming your Sturmey-Archer dynohub is rated the same as every ... Forget a dynopowered rear light of any kind. ... I use it as a daylight running lamp. ... Or, in LEDs, you can fit as many low consumption LEDs as you can ...
    (rec.bicycles.tech)
  • Re: Light Fair
    ... There is some difference in the lamp layout between the ... two areas which may also contribute, but the 19W CFL has more lumens ... That is one of the potential advantages of LEDs ... The CRI of the CFLs that were installed ...
    (sci.engr.lighting)
  • Re: Light Fair
    ... There is some difference in the lamp layout between the ... That is one of the potential advantages of LEDs ... The CRI of the CFLs that were installed ... The most immediate downside to Lutron dimmers on any LED product is that all Lutron dimmers "choke" the top end, some as much as 80%, and although this is hardly noticeable on incandescent, it really reduces our top end. ...
    (sci.engr.lighting)
  • Re: Light Fair
    ... Yes, that's the lamp. ... barring any infant mortality or installation issues, ... That is one of the potential advantages of LEDs ... Again most consumers don't know or care that much about CRI as long as ...
    (sci.engr.lighting)
  • More LED lamp dissections.
    ... Many of these lamps are rated similarly due to their use of the same basic circuit, ... The circuit board in this lamp is quite refreshing in that it uses just one single sided circuit board. ... The 24 LEDs are arranged on the round PCB in the usual circular symmetrical pattern in a single long series circuit while the capacitive dropper has been hard wired to the back with a minimum of components and soldered to pads mounted wherever they would fit between the LEDs pads and tracks. ... A 270nF 400V capacitor with a 1M discharge resistor soldered directly across it's terminals, a 240 ohm inrush limiting resistor and a dil style rectifier. ...
    (sci.engr.lighting)
Loading