Stupid question? or Stupid person? 12v --> 9v

Started by Chris S, July 25, 2004, 08:45:05 PM

Previous topic - Next topic

Chris S

Hey not sure if this is a really stupid question or not...

How do I convert 12v (1.3A) (a battery) to 9v suitable for powering effects pedals?

Thanks!!!

petemoore

just make certain all the actives and capacitors are rated for the power supply voltage, [which they probably are], and double check the polarity so + actually goes to + and - to -...
 if it has a DC jack, chances are very good that they used at least 16v caps, just hook it up and replace any caps below rated less voltage than the PS.
 I use these alarm batteries, like brick shaped, and they last for almost a year with the current draw I demand from them, they go up to nearly 15v.
Convention creates following, following creates convention.

Hal

i think the _best_ choice would be a zener diode with a 3v voltage drop.

or you could use a voltage divider.

or just run at 12 v.  Most efx can take it.

DaveTV

If it has to be 9V, then I might suggest a 9V voltage regulator like a 7809.

Gilles C

Stupid answer:

http://www.uoguelph.ca/~antoon/circ/car912.htm

Use too many parts...

Better answer:

http://www.eidusa.com/Electronics_Voltage_Regulator.htm

That's what most people use.

Simpler answer:

http://www.kpsec.freeuk.com/powersup.htm

Don't forget to check:

http://www.eleinmec.com/article.asp?20

A resistor and a Zener. The minimum voltage regulator.

Arno van der Heijden

Wow, that site on power supplies is really cool and helpful!! :D

zener

Ok, this time it's OT but within the title of the first post.

There are many stupid people, regardless of what level/standard of stupidity one may base it to say that a person is stupid.

There are few stupid questions. Your question is not stupid at all. A question asked out of ignorance is NOT a stupid question but a step in acquiring knowledge.

My 2 cents:  :roll:  (ugh)
A stupid question is a question which composition doesn't adhere to accepted principles of logic.

Example of a stupid question

When I was in my first year in college, one of my classmate, as he was discussing in front in our language class, dared the class to answer this question:

Why is it that water is wet?  :shock:

To my surprise, nobody from the class reacted and it seems they were astounded by this question as if it was a big puzzle :shock: . Moreover, the professor didn't utter a word regarding the question. I dunno if the prof just let it go or he just didn't know too :? . I didn't dared to stand up to point the invalidity of this question because 1)the guy might be humiliated 2)the class could have thought that i'm showing off. It was just the 2nd day in class so we were still pretty much strangers to each and everyone.

The class ended with the question not answered. AFAIR, the guy seemed to be really believing in himeslf when he asked question as if it was a valid one worth to be reckoning with like a true puzzle.

I can explain it myself but I think anybody here can tell why the question is stupid.
Oh yeah!

Lonestarjohnny

Zener, As Mr. Spock said " That does not Compute ",
:D
LonestarJohnny

Paul Marossy

No, no. Spock raises one eyebrow and says "fascinating".  :wink:
If it were me, I would do the voltage regulator. Running effects designed for 9V on 15-16V can make otherwise quiet pedals much noisier.

Gilles C

Just to add to Zener's comment,

Of course,

There are no stupid questions, only stupid answers

That's what we say around here.

And we also say:

The only stupid question is the one you don't ask.

If you don't ask, you"ll never know.

-------------------------------------------------------

I remember that when I was still at school, every time someone was feeling stupid when asking a question, a few students were glad he asked the question because they didn't know the answer...

--------------------------------------------------------

But also words should not always be taken literally. Like, someone could say: "I must be blind tonight, I just don't see it." I don't think he meant he was really blind.

In my head, I just translate to "I should know this, but I don't." or "I just don't remember this." or "I wonder how it works", etc...

QuoteWow, that site on power supplies is really cool and helpful!!

Yeah. That's the fun part of trying to find an answer to a question. We find interesting things (sometimes).

---------------------------------------------------

Btw, when I said:

QuoteStupid answer:

http://www.uoguelph.ca/~antoon/circ/car912.htm

Use too many parts...


I meant "It works, but it's not the best solution"...

Gilles

Chris S

Thanks for all the replies!

Sorry if I caused offence with the title... That's a combination of my Australian Self depricating humor and my love of South Park (the boys teacher often says "there are no stupid questions only stupid people"). I'll stick an appropriate emicon in next time  :wink:

Chris

zener

Note from my earlier post: My definition of a stupid question is (quite? a bit?) "technical". :roll:

No offense at all, Chris :wink: . It's just that people tend to think they are stupid or ask something stupid only because they are ignorant. I, too, used to say that when I was new here in this forum. Nobody was born with a "pre-knowledge". All of us were once ignorant and still ignorant on many other things :)  

Anyway, I'll stick with a 7809 regulator. Easy to install, no other components. No, just one cap (.1uf?).  

QuoteThe only stupid question is the one you don't ask. If you don't ask, you"ll never know.

That can be also said this way:

It's better to feel (be) stupid for a while for asking a (perceived) stupid question than to feel (be) stupid all your life for not knowing the answer to that question.
Oh yeah!

Mark Hammer

I taught university for about 15 years, and I can tell you the following truths:

* Many people misinterpret the the fact that no one seems to be asking a certain question for the possibility that everyone other than themselves already knows the answer.  They probably don't, and have simply not asked.

* Many people mistake the fact that they have insufficient terms or experience to form the question very well with the possibility that the question does not need to be asked.  If you don't know how to ask it, that may make for a clumsy start to the answer, bu that also makes it all the more crucial to ask (and answer).

* Many people misinterpret the sense that they are seemingly the first or only person asking the question with the possibility that many others besides them will not pay attention to, or benefit from, a decent answer to it.  Every simple question asked performs a public service in the eyes of the 20 people who *didn't* ask it.  When the forum where the question is raised is known to attract those wishing to learn and understand more (or who may mistakenly think they know/understand more than they do), you can probably up that ratio to about 40.

* Many people mistake the fact that their question strikes them as being simple or basic in focus, with the perception that it will not spark much bigger ideas, or revised thinking, in those who are able to answer it.  In fact, many of the biggest and best ideas come from people with a bit more knowledge answering basic questions from others.  "How come...?" is often the best place for a bright idea to be born.

* Many people mistakenly assume that those who know more than them (or who they *believe* know more than them) are always clearly aware of it.  Not true.  It is often the case that those with a little more knowledge become MORE fluent in what they know whenever they have to gather their thoughts/knowledge together to provide an answer.  Sometimes, you don't know what you know until you say it.  That's why the people you used to consult in high school and junior college were so smart: every time they explained something to their buddies they understood and organized more of what they knew.  YOU were the one who made them expert.  Too bad you never go to share their grades.

* How can you tell the difference between a "stupid" question and a basic one?  Very simple.  If the asker wants to know and understand more, it is a basic question.  If the asker indicates no desire to understand more by the way they pitch the question (i.e., an indication that they wish to *remain* uninformed) then its a stupid question.  As a prof, I can say that pretty much the only stupid questions I ever fielded started with "Do we have to know X (e.g., for the exam)?".  No matter how basic or clumsy the question, it is hard to turn your back on an eager learner.

zener

Damn, shame on me.  :oops:  There should be a fine line between a "stupid question and an "invalid" question. I have thought of it as almost, if not equally the same.

The invalidity of a question can be determined from how the question was laid down and/or what matter is being in "question". The principles of logic and correct language will tell.

The stupidity of a question lies on the intentions and/or or the mindset of the asker when he asked the question, as what Mark said.

The question my classmate raised is an invalid one. His aim is just similar to giving a riddle or a puzzle. But from how I recall all of his demeanor, facial expressions, vocal intonations, it's like he was really sure that it was a valid question and there's an answer, if not scientific :shock: , valid enough.

In my utter disappointment with how that question caused to be like a big puzzle to class (I should have raised from the seat), I dubbed it as a stupid question from what I had seen from him even without knowing the intentions of the asker. I never had the chance to know afterwards. :roll:
Oh yeah!

Jason Stout

QuoteWhy is it that water is wet?  

I think this is a valid question!  :D

Are all liquids "wet" ?
What IS "Wet" ?

Example, in my opinion, mercury is not wet.

IMO "Wet" is a feeling that comes from water's viscosity and the surface tensions involved.
Jason Stout

petemoore

Adressing the 'stupid' questions...
 There's a good thing about typing stupid questions, by putting in in words, and re-arranging or editing them to form a more intelligent and concise question, often the answer becomes clearer as the question 'forms' into a more intelligent phrase.
 Just typing the question out, and looking at it, inspecting it for better wording, the answer often pops up  :idea:
 I just think "What would R.G., or Mr. Hammer think of this", :D and the answer is there, other times I post, 'half' knowing of the correct answer.
 Then there's 'lazy' questions, these are the ones where the mind isn't working properly enough to see that the answer is neatly contained in the question, or where just a bit of focus, and some quick testing would find a very  suitable and detailed  answer...
 FInding the answer...if you're memory's not shot like mine, this is a good method to use...that way you can always remember the way back to where you found it.
Convention creates following, following creates convention.

Mark Hammer

That's *Mark*, not Mr. :roll:

The first step to solving any problem is defining what the problem is.

zener

Since the topic (12v->9v) has been cleared already, I'll jump and drop my 2 cents on why I dubbed it as an invalid question.

First, the question actually intend to say "liquid" instead of "water" but since water is the most common liquid, it can be considered the same for the sake of this argument only.

In a short talk, the invalidity of the question simply lies on "cause and effect" (law?).

The water is the *cause* and the *effect* is wet. How can be an effect occur or become an attribute of something when that stuff is the only thing that can make the effect happen?. This argument is a bit unique from other "cause-and-effect" because there can only be one ultimate cause to the effect in question.

In the question, water is a noun and wet is an adjective. I dunno if anyone will agree with this. IMO, An object can be said to be wet if it posseses water in it and anyone can sense the presence water often by touch or can also be by sight. To shorten it, an object is wet if it has water and you felt it.

Now, If we're going to substitute (my) definition of being wet to the actual word in the question, it will be like:

Why is it that water has water in it?

The extended version makes it more even more ridiculous

Why is it that water has water in it that I can feel/see?

My 2 cents. Maybe some might just laugh why do I even bother to dig this :roll: . Anyway, that's just for a while. I would love to hear others' thoughts.
Oh yeah!

Paul Perry (Frostwave)

Quote from: zenerThe water is the *cause* and the *effect* is wet.... IMO, An object can be said to be wet if it posseses water in it and anyone can sense the presence water often by touch or can also be by sight. To shorten it, an object is wet if it has water and you felt it.

Next we'll be arguing whether an effect in the forest is "on" if nobody can see the led, but....
I would consider 'water' as a name of a particular substance.
And the substance has certain characteristics, giving rise to sense data that we interpret as "wetness" (liquidity, a certain range of viscosity, density, thermal conductivity, and thermal capacity).
now, can you "wet" yourself with kerosene? I think so, though it is a slightly different experience to being "wet" by water.
And, to get back to FX, be sure your solder "wets" the tip and the objects being soldered  :D

Arno van der Heijden

Does the fridge light stay on when the door is closed?  :? :mrgreen: