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> LED light bulbs have built-in inverters Think you meant rectifiers here.
by pitaj 5y ago
> LED light bulbs have built-in inverters
Think you meant rectifiers here.
- Pet_Ant 5y agoCan you clarify the difference?
- pitaj 5y agoGenerally Rectifier = AC to DC and Inverter = DC to AC
- Johnythree 5y agoSorry, but no. An inverter uses switch-mode technology to enable voltage conversion. Usually this allows using small high-frequency transformers, rather than large 50/60Hz iron cored units. Which is why so many wall-warts use Inverters to step the voltage down.
- pitaj 5y agoYes, switching power supplies can be used to go from AC to DC, but those are not inverters. They're a form of active rectifier. Perhaps you learned it differently, but according to any source I can find, they're defined as I said.
- faeyanpiraat 5y agoInverter: DC -> AC Rectifier: AC -> DC Edit: whoops I'm late to the party
- namibj 5y agoActually not really... A single-phase-AC-sourced rectifier does need a considerable output capacitor, though, and it will have a poor power factor with severe harmonics unless it spends extra on PFC which would not be necessary with a local DC grid supply (say, 320V DC to replace 230V AC systems to match peak voltage; yes the higher RMS voltage results in (anti-)proportionally reduced current, allowing cheaper/thinner wires or less loss).
- pitaj 5y agoMany LED bulbs are a simple diode rectifier circuit, essentially with a bunch of LEDs stacked to add up to a total 120V bias voltage. These will blink at 60Hz or 120Hz depending of if they implement a half-wave or full-wave. More complicated bulbs use an active rectifier / switching power supply instead.
- namibj 5y agoThose are kinda shit, though. Also, the ones you're thinking of should be capacitive dropper circuits, if I'm not mistaken. There's also the electrolytic-smoothed bridge rectifier variant. BigClive has a lot of teardowns of such light bulbs (and non-bulb-shaped alternatives) with circuit diagrams and explanations. They're really good for learning about the various "cheap LED bulb" designs.