If it were easy to make a highly efficient 1 transistor oscillator/LED driver that was highly efficient and somewhat insensitive to supply variation, inductor properties and LED type I don't think they could make much $$$ selling 3 terminal integrated boost converters for driving single LEDs for 75 cent in singles
Whoops, it can be just single highly-efficient :)
Why would ayone bother to make and package a transistor or an IC and sell it for one cent?
-- John Larkin Highland Technology, Inc picosecond timing precision measurement jlarkin att highlandtechnology dott com http://www.highlandtechnology.com
These are 4.5 cent in quantities of 50, seem to work quite well, I got them delivered to my DHL dropoff location in about 5 days from China. I believe Win posted the link originally.
same reason companies sell resistors for a fraction of a cent?
NT
Thank you. That was very helpful.
-- John Larkin Highland Technology, Inc picosecond timing precision measurement jlarkin att highlandtechnology dott com http://www.highlandtechnology.com
:) Next thing you know, valves will become uneconomic.
6AK5s are $5 for two from Shenzen that's actually a little higher than they're usually listed for.
We have used thousands of a little Hammond extruded aluminum box. They cost $8, need secondary machining, and are generally ugly and awful. We recently got a quote from a Chinese source for a much nicer box, machined to our drawing and anodized, for about $2.50. How can they do that?
We will also either laser blast or ink-jet the lettering, to eliminate buying stickers.
What's nice is that the top lifts off instead of sliding off. This will be nice thermally and for EMI too.
-- John Larkin Highland Technology, Inc picosecond timing precision measurement jlarkin att highlandtechnology dott com http://www.highlandtechnology.com
wait until you have some in hand, I've bought cheap extruded boxes that looked nice on the picture, but in reality made from some extremely light weird aluminium
looks similar to Fischerelektronik,
it might not be nearly as EMI tight as you expect
It's nice looking, but I'd worry about the EMI shielding integrity. There's apparently nothing enforcing good contact across the beltline.
Cheers
Phil Hobbs
-- Dr Philip C D Hobbs Principal Consultant ElectroOptical Innovations LLC / Hobbs ElectroOptics Optics, Electro-optics, Photonics, Analog Electronics Briarcliff Manor NY 10510 http://electrooptical.net http://hobbs-eo.com
The end plates each have four screws, conductive, into the top and bottom halves of the box. That should be pretty good.
-- John Larkin Highland Technology, Inc The cork popped merrily, and Lord Peter rose to his feet. "Bunter", he said, "I give you a toast. The triumph of Instinct over Reason"
At low frequency, I agree. Up where the box length is an appreciable fraction of a half-wavelength, I'd be a bit less confident. The tongue-and-groove design will help a certain amount, I expect.
Round here we get a lot of GHz pickup, which is irritating.
Cheers
Phil Hobbs
-- Dr Philip C D Hobbs Principal Consultant ElectroOptical Innovations LLC / Hobbs ElectroOptics Optics, Electro-optics, Photonics, Analog Electronics Briarcliff Manor NY 10510 http://electrooptical.net http://hobbs-eo.com
GHz, whatever from? Cell towers, wi-fi?
--
Thanks,
- Win
Some of each, I expect, plus a bunch of assorted schmutz. Gentle flexing of the Danish butter cookies tin makes the pickup go up and down by 20 dB sometimes. (It has 33 nF feedthrough caps on the power wires and bulkhead-mount BNCs for signals.)
Irritating for development but probably a good thing overall--we pay more attention to shield integrity that way.
Cheers
Phil Hobbs
-- Dr Philip C D Hobbs Principal Consultant ElectroOptical Innovations LLC / Hobbs ElectroOptics Optics, Electro-optics, Photonics, Analog Electronics Briarcliff Manor NY 10510 http://electrooptical.net http://hobbs-eo.com
Free EMI testing. If we move our hands around and DC offsets change, we fix it. There are some nice EMI-hard opamps around these days.
I use a lot of DBC EMI enclosures. One employee punishment is "no cookies for a week."
-- John Larkin Highland Technology, Inc The cork popped merrily, and Lord Peter rose to his feet. "Bunter", he said, "I give you a toast. The triumph of Instinct over Reason"
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