One of the best parts of being on EN-Genius Network's editorial team is the mail I get from readers. Whether you agree or disagree with me, thank me for my insights or call my attention to a stupid oversight, it's great to hear from you. Besides the satisfaction of knowing that there's somebody besides my Mom reading my articles, your letters are one of the best QC mechanisms for ensuring the stuff I publish meets your tough standards. I've also found that I always learn things from the people who are involved with the technologies. Take for example a recent letter from a reader in response to my Editorial on the emerging LED lighting industry. His letter takes me to task for some sloppy reporting on what I thought was a "breakthrough" in the field.
I've posted his letter below (name withheld for his privacy) along with my response, in hopes that our exchange will help correct any misinformation I may have inadvertently spread in my original story, and provide some new insights on the industry:
From: Ed XXX [mailto:xxxx@comcast.net]
Sent: Wednesday, April 20, 2005 5:45 PM
To: lgoldberg@green-electronics.com
Subject: Seoul Semiconductor and its magic AC LED
As one who has also recently developed an "AC LED", I am amused by the Seoul Semiconductor announcements with the usual Asian press release characteristic of guaranteed absence of any meaningful details.
First of all, there is no such thing as an AC LED chip. An LED is a simply, from an electronic standpoint and aside from the light emission, a diode with a negligible reverse rating. To operate from AC you must do any number of things to drop the voltage and stabilize the current in a "ballasting" fashion. To do this is child's play and has been done in one way or another for 30 years.
However, doing it a) at an acceptable cost, b) in acceptably small size, c) generating sufficient light output and d) without compromising lumen output - is a "whole 'nother ballgame" which separates the men from the boys.
I just last week purchased off the web an "AC LED" for $30 which screws in like a regular bulb. It is embarrassing. The light output is so low as to be a joke.
You will note that the Seoul Semi announcements are careful to stay clear of a thorough description. I could announce a new automobile engine which runs on horsefeathers. The devil's in the details.
As an engineer, tech exec and CEO in the opto-semiconductor and power semiconductor areas for last 30 years, with over two dozen commercially viable patents myself, you can see where my amusement comes from.
It is rather amazing that these large Asian companies publish these nonsensical press releases but this is not limited to the AC LED. Unlike most US companies, the Asian semiconductor companies seem to have a major disconnect between their technologists and their sales people.
Ed
Here's My Reply:
Hi Ed - Thank you for the note, and for bringing your observations about the Korean AC LED bulb in my recent Editorial "Blinded By The Light" to my attention. I'm keenly interested in solid-state lighting technology and try to follow it as closely as I can but occasionally get things wrong, so feedback from a knowledgeable reader like yourself is not only welcome, but essential. You make several excellent points here which I'll try to address, and to clarify a few things you may have misunderstood when you read my editorial.
You make a very good point that I should not have taken the Korean press release about their "AC-LED" at face value, but in this case, I was more using it to make a point about the market opportunity, and the need for American industries to redouble their efforts in solid-state lighting than to endorse or analyze that particular product.
When actually reviewing a product, much of my energy goes into trying to sort out the manufacturer's claims from the actual performance of the device, something that gave rise to the infamous "Vaporware Index Rating" that I attach to my reviews. If this had been a real product review and not simply noting an industry trend, I'd most likely have done a bunch more digging before I published anything. But even in this case, I guess a little bit more "due diligence" was in order and appreciate the feedback.
I am very aware that there is no such thing as an "AC-LED" per-se, but I've seen (and reviewed) several LED-based lighting products that use various schemes to run off a 120 Vac circuit without a costly and bulky transformer. After having actually seen a 100 W equivalent HB-LED screw-in light module a couple of years ago (retail price $100), and owned a lovely set of direct-ac LED Christmas lights (Retail $15), the Korean announcement seemed to be reasonable enough to use as an example to try to shake American industry out of its complacency. But if the product you tested was as bad as you say, I made a big mistake in touting it as a "breakthrough" and apologize for not doing my job properly.
I was not sure, however, from your letter if the AC-LED you purchased was from Seoul Semi, or from some other manufacturer. Please clarify so I can get my facts straight. This is important because I was considering doing a review of Seoul Semi's AC-LED product and had written the company once to try to get a sample for evaluation, but with no results. I'll try again if it seems worthwhile to do so. Depending on whether the inferior product you tested is from Seoul Semi or not, I'll see if it's even worth making the effort to bother them again.
All this aside, the point of the Editorial remains that HB-acLEDs can play an important role in reducing global energy consumption and that innovative companies stand to benefit from getting an early start on bringing these products to market. I stand behind that and look forward to seeing innovations in solid-state lighting begin to improve our environment and quality of life in the near future.
And speaking of bringing things to market, when will your product be ready, and would it be possible to do a review of it at that time? I'd love to share any interesting news you have with my readers. Please let me know if you are interested in working with me on this.
Whether or not I have the opportunity to review your product and discuss your technology, I really appreciate you bringing the shortcomings of my Editorial to my attention. I'll do better next time thanks to your prodding.
Best regards,
LEE
Hopefully I'll hear from "Ed" in the near future and find out whether or not the products I gave such enthusiastic endorsement to were the same ones he tested and found to be inadequate. I also hope that I'll have a chance to review his solid-state lighting products as soon as they are ready to hit the market. In any case, he's already done us all a favor by keeping me honest and making me live up to the high standards you expect here at EN-Genius Network.
Comments? Questions? Other bones to pick? Write me at: lgoldberg@green-electronics.com
