4 ms·
The 10khz+ flicker only comes about if the bulbs have a proper switching power supply (and if that switching power supply itself runs at 10khz+). But for the '
by pwg 7y ago
The 10khz+ flicker only comes about if the bulbs have a proper switching power supply (and if that switching power supply itself runs at 10khz+).
But for the 'real cheap' bulbs, they likely (due to being "real cheap") have either a half wave or full wave rectifier (i.e., no switching PSU) which results in the LED's having a flicker at power line frequency (either 50hz, 60hz, 100hz, or 120hz depending upon which combination of line frequency and full/half wave rectifier is present).
- nicolaslem 7y agoNow that incandescent bulbs are almost gone, I wonder if it will become common to have wires carrying DC in the ceiling instead of every bulb having to implement the AC to DC conversion as cheaply as possible.
- andruby 7y agoThen we can also use this for our video camera’s and wireless access points. Maybe we can add network to those cables. Let’s call it “power over ethernet” ;)
- elFarto 7y agoUbiquiti has got you covered: https://unifi-led.ui.com/ https://unifi-led.ui.com/
- zaroth 7y agoI have DC powered under-cabinet lights which are definitely flickering at some fairly high rate. Imperceptible if you are just looking at it, but in a dark room if you move something quickly in front of it you can see the strobe effect.
- 205guy 7y agoBut where is the DC coming from? If it is a cheap power source (a rectifier plugged or wired into AC), the DC into the lights could be intermittent, and so cause flicker. For true continuous DC, you need a good rectifier or get the current directly from batteries.
- 205guy 7y agoWith renewable energy and local batteries, it would make sense to have DC wiring. It used to only be that off-grid systems had batteries (usually lead-acid), and they always just use an inverter. But now with battery packs such as the Tesla Powerwall, even grid-connected houses have DC storage. Unfortunately, Powerwalls and other similar products are made with built-in inverters and connect only to AC, there is no DC tap. And there aren't any standards around DC wiring and small appliances, so it isn't likely to get traction. I'm mentioned before (https://news.ycombinator.com/item?id=21109247 https://news.ycombinator.com/item?id=21109247) that I've seen a DC installation at a friend's house, he used 12V cable lights and DC bulbs, so it seems to work.
- kps 7y agoThe real cheap filament style bulbs are a rectifier, and nothing but.