携帯電話用に良く使われているイヤホンマイク用のスタンドアロンのマイクアンプ。 オペアンプによる反転増幅回路を２段重ねた簡単なもので、それぞれのマイクに合わせてバイアス等は適宜変更する必要がある。 以下の回路では使用していないが、位相補償コンデンサを追加した方が雑音が少ないと思う。 オペアンプは単電源、入出力フルスイングオペアンプのNJM2732を採用したが、 これ以外の低電圧対応入出力レールツーレルオペアンプでもおそらく動くだろう。NJM2732は出力電流が2mA程度までしかとれないので、受け側のインピーダンスが数百Ω等の低いものは使えない。
One thing hackers like is brevity. Hackers are lazy, in the same way that
mathematicians and modernist architects are lazy: they hate anything
extraneous. It would not be far from the truth to say that a hacker about to
write a program decides what language to use, at least subconsciously, based
on the total number of characters he'll have to type. If this isn't precisely
how hackers think, a language designer would do well to act as if it were.
It is a mistake to try to baby the user with long-winded expressions that are
meant to resemble English. Cobol is notorious for this flaw. A hacker would
consider being asked to write
add x to y giving z
instead of
z = x+y
as something between an insult to his intelligence and a sin against God.
-- Paul Graham
-- Being Popular ( http://www.paulgraham.com/popular.html )
If you work your way down the Forbes 400 making an x next to the name of each
person with an MBA, you'll learn something important about business school.
You don't even hit an MBA till number 22, Phil Knight, the CEO of Nike. There
are only four MBAs in the top 50. What you notice in the Forbes 400 are a lot
of people with technical backgrounds. Bill Gates, Steve Jobs, Larry Ellison,
Michael Dell, Jeff Bezos, Gordon Moore. The rulers of the technology business
tend to come from technology, not business. So if you want to invest two years
in something that will help you succeed in business, the evidence suggests
you'd do better to learn how to hack than get an MBA.
-- Paul Graham
-- How to Start a Startup ( http://www.paulgraham.com/start.html )