- #26
NoTime
Science Advisor
Homework Helper
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Data sheet looks fine to me.{Wait, stop the presses! I've had a brainstorm. A single component solution @ 19.95 bucks is available in the lighting section of your local home despot.}
What does BOE mean?
I don't like the data sheet. I'd guess 70 ma peak would thermally degrade the diodes. 60 Hz is so slow it's nearly DC for the thermal mass of the die embedded in plastic, wouldn't you say? The data sheet is just not good enough to tell us. I'd use a bridge, though. For the cost of three more diodes, the average current is doubled for the same peak current. I was thinking 44 series diodes and a bridge.
But then again, maybe you're right aiming at 70ma peak. Without better data or prior expertise, experimenting is in order.
It has all the information you need to work this out, including any thermal effects.
BOE = Back of Envelope. Quick and dirty but close.
Using a bridge bumps the freq to 120Hz, but doesn't add that many LEDs to the string.
I thinks it's around 28 or so.
Don't forget you're effectively lowering the supply voltage + adding resistance.
Peak current drops quite a bit.
There shouldn't be an issue with 70ma peak thermal since the actual duty cycle is low.
I also took worse case so the actual peak will be lower.
No idea if if actually would flicker with the single diode.
Experience says some people might see it and some wouldn't.
Homework assignment: Show the math for working the bridge case out
The answer is definitely not a count of 44.