Luxeon 1 watt lighting system

[solis365]

back to what the OP is asking...

running the LEDs directly from AC is something that has always intrigued me.
Circuit - AC Powered White LED Strings
is one page that discusses this. Keep in mind most of these projects will be for standard (20mA) LEDs and not the high-powered luxeons you have, but are easily adaptable.

if you attempt this you will need to use a 3-prong plug with earth ground on one of the prongs and tie this earth ground to any exposed metal (like the heatsinks youll need for the luxeons)

this might make your setup more compact, more efficient, and a lot cheaper. transformers are big and expensive and heavy. However if you have very sensitive eyes you might see the flicker. I cannot see the 60Hz flicker, so it works for me.

oh and if you dont know what you're doing with AC power dont try it unless you are confident in your ability to do it safely. its pretty dangerous stuff, I almost killed myself the other night with it (fortunately I was being smart and using the "one hand in the back pocket" thing when my project started to spark...)

 

[Ray@]

1 Watt LED

I was going to use DC 12V..Chevy Truck

 

[Ray@]

Thanks Driver300, now I just need to find those resistors

 

[RCinFLA]

Cheap A.C. LED driver

LED's for lighting from A.C. main is often are done with a low cost capacitor ballast system.

Their are several variants of the circuit that use series capacitor as the reactive ballast.

The ballast cap is in series with the A.C. input to a fullwave rectifier bridge. The series cap adds the reactance necessary to produce the current sourcing necessary for the diodes.

There is a secondary purpose circuit that protects the LED's from an accidental quick turn-off, turn-on that might result is the still charged ballast cap adding to the instant peak voltage of the A.C. input waveform when switched 'ON' that can potentially over voltage the LED's stack. This is usually no more then a small resistor (50-100 ohms) in series on bridge rectifier output and a 47 uF electrolytic across the LED diode stack. The 47 uf is much larger then the ballast cap so it dampens out any ballast-A.C. voltage stacking. The 47 uF can be replaced with a zener diode whose voltage is greater then worse case forward bias voltage of the LED stack. The below web links do not include this protection circuit

This works from one diode to a stack summing to half the A.C. line voltage.

Second variant of this circuit eliminates the rectifier bridge by using two parallel LED stacks each having their own ballast cap. Positive A.C. cycle activates one stack, negative A.C. cycle activates the other stack.

Just be a bit careful working on it live as there is no A.C. isolation.

AC Powered White LED Strings

**broken link removed**

 

[solis365]

I was going to use DC 12V..Chevy Truck

That is because I was replying to the Original Poster's question, which was about running them on 230V AC in his shop. While your question was relevant to the topic and I would he happy to help, it is best done by starting your own thread in the forums, what you have done is "hijacked" fever's thread and diverted the discussion away from his question.

 

[giftiger_wunsch]

That is because I was replying to the Original Poster's question, which was about running them on 230V AC in his shop. While your question was relevant to the topic and I would he happy to help, it is best done by starting your own thread in the forums, what you have done is "hijacked" fever's thread and diverted the discussion away from his question.

The question is almost a year old, and while I agree that he should have started his own thread, most likely the actual OP has long-since solved his problem anyway

 

[solis365]

The question is almost a year old, and while I agree that he should have started his own thread, most likely the actual OP has long-since solved his problem anyway

Oh wow I didn't even notice the date. so he dredged up an old thread, I see.