Re: Using a Wall Dimmer on LED Lightrope
- From: D from BC <myrealaddress@xxxxxxxxx>
- Date: Sun, 01 Apr 2007 17:42:13 GMT
On 1 Apr 2007 09:46:05 -0700, omattos@xxxxxxxxx wrote:
On Apr 1, 6:43 am, D from BC <myrealaddr...@xxxxxxxxx> wrote:
I'm dimming a 9ft piece of manufactured LED lightrope with an ordinary
household wall dimmer.
The nice thing about using a wall dimmer is that it doesn't get hot,
it's cheap, easy to get and no lightrope mods are needed.
The lightrope has an internal diode and internal resistors to run off
120VAC.
With the dimmer full on, I don't notice any flicker.
However, flicker seems more noticeable (but still subtle) when the
lightrope is dimmed.
I suspect some combo of LED curve + dimmer waveform + eye persistence
time to account for the flicker.
So.... how to get rid of the flicker and still use an ordinary wall
dimmer?
Could I put the dimmer in series with a bridge rectifier? That'll put
the flicker at 120Hz..
Or...
Maybe design a more appropriate dimmer?
D from BC
Going back to the original plan of a bridge rectifier - it may not
work because then the average power through the light-rope is doubled
(full wave not half wave), and it may overheat. You could compensate
for that by setting an upper limit on the dimmer, or rewiring the
series/parallelness of the lights in the tube.
Another alternative is to put a large capacitor in parallel with the
lightrope, as while the lightrope will still get dimmer through the
"off" parts of the cycle, it won't be fully off and that looks better
to the eye.
Ahh..good point about the average power... I didn't think about
that..The lightrope has probably been designed to be max brightness
(with long life) with half wave.. (The lightrope has that internal
diode + LED's are diodes.)
I'll compensate with full wave..Thanks.
Seems a bit scary to put a filter cap in parallel with the lightrope.
Let's say power it's switched on right at the sine peak
(~170V)...That's a big inrush current spike.
Wouldn't that blow the dimmer(triac) + bridge rectifier combo?
D from BC
.
- References:
- Using a Wall Dimmer on LED Lightrope
- From: D from BC
- Re: Using a Wall Dimmer on LED Lightrope
- From: omattos
- Using a Wall Dimmer on LED Lightrope
- Prev by Date: Re: TI-Burr-Brown parts shartage?
- Next by Date: Re: Thoughts about tube output stages...
- Previous by thread: Re: Using a Wall Dimmer on LED Lightrope
- Next by thread: Re: Using a Wall Dimmer on LED Lightrope
- Index(es):
Relevant Pages
|
