Analog Discovery

簡易的PWMスイッチング電源で有名なNJM2374を試用した例。10kでVrefを2倍しているので、出力電圧は約2.5Vである。実はブレッドボードを使い始めたはかなり最近で、それまではすべてハンダ付けして試作していた。接触不良やインダクタンスの問題に悩まされることはなく、そのまま試作機に組み込めるという利点はあったものの、修正を含めれば時間は結構それなりにかかるので、時を場合により、ブレッドボードを使う試作方法を選んだ方が良さそうである。

回路上は出力側が100µHと33µFで、負荷抵抗はつなげていない状態である。リンギングというかLCによる共振がかなり大きく出ており、計測上769kHz(周期1.3µs)で、入力側にはコンデンサを付けてないのと負荷にもよるし、ブレッドボードを使ったので、寄生インダクタンスもかなりありそうだが、基板を起こしても出る場合は、スナバ回路は必要かもしれない。ブレッドボードはスイッチング電源の評価には不適切で、プロービングの問題もあると思われる。

Rule of Open-Source Programming #9:

Give me refactoring or give me death!

    -- Shlomi Fish
    -- "Rules of Open Source Programming"

Now, however it was initially intended, I think BASIC turned out to be one of
the first major scripting languages, especially the extended version that DEC
put onto its minicomputers called BASIC/PLUS, which happily included recursive
functions with arguments. I started out as a BASIC programmer. Some people
would say that I'm permanently damaged. Some people are undoubtedly right.

But I'm not going to apologize for that. All language designers have their
occasional idiosyncracies. I'm just better at it than most. :-)

Anyway, when I was a RSTS programmer on a PDP-11, I certainly treated BASIC as
a scripting language, at least in terms of rapid prototyping and process
control. I'm sure it warped my brain forever. Perl's statement modifiers are
straight out of BASIC/PLUS. It even had some cute sigils on the ends of its
variables to distinguish string and integer from floating point.

But you could do extreme programming. In fact, I had a college buddy I did
pair programming with. We took a compiler writing class together and studied
all that fancy stuff from the dragon book. Then of course the professor
announced we would be implementing our own language, called PL/0. After
thinking about it a while, we announced that we were going to do our project
in BASIC. The professor looked at us like were insane. Nobody else in the
class was using BASIC. And you know what? Nobody else in the class finished
their compiler either. We not only finished but added I/O extensions, and
called it PL 0.5. That's rapid prototyping.

    -- Larry Wall
    -- "Programming is Hard, Let's Go Scripting" ( http://www.perl.com/pub/a/2007/12/06/soto-11.html )

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Analog Discovery - NJM2374