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Tw questions on LED bulbs. First Qt: Just something I was wondering. Since LED's bulbs are, by definition rectifiers ( I believe they are full wave) would it be possible to use them as such by putting a standard light bulb socket in a circuit?

Edit

Second question was cut and reposted elsewhere

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    \$\begingroup\$ You should ask this as two questions. \$\endgroup\$ – Phil Frost Jan 28 '14 at 23:32
  • \$\begingroup\$ When you say "LED bulb" do you mean AC mains powered LED bulbs? | LEDs themselves make TERRIBLE power rectifiers. They have extrmely low tolerable max reverse voltages (maybe 5V) and allowed reverse currents may be uA. | An LED bulb may CONTAIN a full wave bridge rectifier but this is a super expensive way to obtain one. \$\endgroup\$ – Russell McMahon Jan 29 '14 at 6:12
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Since LED's bulbs are, by definition rectifiers ( I believe they are full wave) would it be possible to use them as such by putting a standard light bulb socket in a circuit?

No, they are not full wave rectifiers....

They are rectifiers but, the purpose of a diode rectifier is twofold; one to conduct current in the forward direction (LEDs do that) AND block voltages in the reverse direction (ordinary diodes do that easily but most LEDs breakdown after a few volts). This almost certainly means that LEDs will destruct on anything other than a low voltage AC circuit - maybe 3VAC maximum and, this is no good in the application the OP considers.

The 2nd question I cannot answer BUT, it ought to be asked seperately because I don't see a connection in anything other than the use of the term LED. The connection with LEDs is as tenuous as it comes I believe.

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Q1 only (can't help on Q2) ... I don't think this is quite right (but I'm not by any means an absolute expert...)

Most LED bulbs are made up of many many discrete LEDs arranged in a manner that balances how the designer wants the light to emit from the devices themselves, and by the circuit/board designer wants the electronics to work. The light designer cares about how many lumens, the color rendition, and the appearance of the bulb -- in short, the stuff that customers care about. The circuit/board designers care about how to efficiently get power into the LEDs and then dissipate all that heat that gets generated, since LEDs and the corresponding circuitry that drives them are far more sensitive to heat than a classic incandescent (tungsten) filament bulb. And while the simplest rectifier is built from a set of diodes, in an LED bulb all of the AC->DC conversion is "local" to the circuit that drives the LEDs themselves... to the rest of the power system it appears to be "almost" a resistive load. See references below for a measurement of the power factor of an LED bulb that's near 1.0.

http://www.designingwithleds.com/cree-60w-led-replacement-bulb-review-and-tear-down/ http://www.designingwithleds.com/qa-with-cree-about-60w-replacement-led-bulb/ http://www.candlepowerforums.com/vb/showthread.php?360936-Cree-quot-60W-quot-800lm-A-shaped-LED-light-bulb-teardown

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