9V 1A schematic needed

Still not clear. You want 9.0000VDC up to 1A from 90-264VAC? It's very difficult to buy ONE EACH transformer of the types you want. I expect you haven't considered the subtleties of the design...high line, low line, efficiency, heat sinking, trough voltage...the list is endless...schematic is trivial, but the details won't show there. You're more likely to have to design around an available, non-optimal transformer.

You're MUCh better off to buy a switcher wall wart to do the job. If you only want one and you're cheap like me, I'd start looking for cellphone chargers. Or laptop charger and change the voltage setting resistor. If it has to be inside, it's still easier to break it open and mount the board inside. mike

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Return address is VALID but some sites block emails
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Now that you've clarified the fact that you need a power supply --

How much better is smaller? If size really is paramount then you need to make an off-line switcher, which isn't a trivial task. If you can get away with 6-10 cubic inches (about 2/3 of a cup) then you should be able to do the transformer -> rectifier thing.

Does it need to be regulated? If so then you need a transformer -> rectifier -> regulator.

Look around on the web for "power supplies" -- that's really what you want. Or go get the latest ARRL handbook, which will have lots of examples and "how to" information.

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Tim Wescott
Wescott Design Services

Still not a clue. This power supply doesn't say if it's regulated. Look at their list of power supplies. Some say they're regulated, this one doesn't. Does that mean it isn't? Or just forgot to put it? NO SPECIFICATIONS LISTED.

If this unspecified power supply meets your needs, you're probably not gonna find a transformer smaller than the one in there. Bust it open and use the parts.

The schematic for what you want is trivial. Transformer feeds diode bridge or two diodes, depending whether you have a center-tapped transformer, into a capacitor. Now all you need to do if figure out how much ripple and min/max voltages you can stand. Then you need to buy a transformer that does that...and you probably won't find one.

So, we're full circle. Go buy the wart and take it apart. Then instead of having a well protected wall wart supply, you'll have AC running around in your project, shock hazard, fire hazard....there's a reason most products today use wall warts.

mike The simplicity of the answer is inversely proportional to the simplicity of the question.

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LMAO!!!! Larry gave a very direct answer to the OP's question. He specifically asked for a schematic for a transformer. It was all very tongue-in-cheek. I thought about giving a very similar answer but Larry beat me to it.

All that said, the OP still hasn't given enough info to give him a definitive answer to his needs. Lacking are such details as... Is regulation required? What are the allowable ripple/noise? Does he need a PSU that can be easily switched between 120/240 mains voltages, or is a single mains rated input sufficient? What are his size limits for the unit? etc., etc.

LMAO!!!!

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Dave M
MasonDG44 at comcast dot net  (Just subsitute the appropriate characters in 

[Responding to a query from the OP, aka "J-vibe" quoted with leading '>>>' now:]

about...

Oh master, once again, as usual, your presciendent wisdom and beneficence is a wonder to behold.

I struggled and struggled to get my thoughts going, dimly recognizing that, in this NG, the OP did not mean the toy that my son briefly treasured, and, after what seemed like eons, I managed to grasp that the OP meant something electronical. After more struggle, and with the help of a friend who seems to know some electronical factoids, I learned of the transformer and its appearance in some strange pictoral language most foreign to we lower members of the mineral kingdom.

Now it seems, thanks to your gracious willingness to share tidbits from your vast store of knowledge, that the OP was talking about something else entirely. Oh, woeful am I to have failed in your eyes, master. Ever hoping to gain your approval, but still ignorant of the OP's true meaning, which must be opaque even to your perspicious, thoroughly exaltable self, (because, surely, you would share that clue were it otherwise), I will attempt to gather my meager wits and formulate a response more suitable to you.

To the OP: Please be patient with my efforts to please the infinitely exaltable Fred Bloggs. He sets such an inimitably high standard by example with his wise and kind posts that others can hope for only the most excrescential results in comparison.

So, without further ado, here is my humble retry:

Yes, it surely is.

You misunderstand. I am not in the least bit upset. I am disappointed that you take Fred's assertion that I had no clue at face value. Perhaps, if you read the 2nd-to-last sentence in my retry with care, you will understand that there was a clue. However, I will admit that my notion of what you were after was extremely vague, as would be natural given your question.

I urge you to read this next paragraph, quoted from my post (but cut from yours as seemingly insignificant) with more care. Be aware also that I attempted to find your email address in your posts, to provide a clearer indication of my intent, but could not find it in either plain or munged form. Quoting: To the OP: Please be patient with my efforts to please the infinitely exaltable Fred Bloggs. He sets such an inimitably high standard by example with his wise and kind posts that others can hope for only the most excrescential results in comparison. I am not going to decode that for you, but I assure you that there is a more benign message there for you.

Agreed, at least up until a few lines above.

If you were to read the bulk of Fred's posts over the last few weeks, I think you would agree that being attacked by Fred is an honor, not anything to feel bad about or wonder how recover from.

I am convinced that the reason for Fred attacks lies in the twisted mind of Fred himself and so I never could imagine that you are to blame for it.

I think you need to read more posts here to understand. If you are as intelligent as I hope, that should do the trick.

I have not killed anybody yet and have many friends I have known for most of my life. My family is intact and they all seem glad to see me.

No need for your apology, since it appears you are the only innocent person offended.

I hope you will accept my apology for not anticipating your superficial interpretation.

I'm glad you got what you wanted. Now, ask yourself "Why did Larry answer my first post in the manner he did?" and "How, as a socially unstable individual, could he have elicited my thanks and a reformulated question without offending me in any way whatsoever?"

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--Larry Brasfield
email: donotspam_larry_brasfield@hotmail.com

Thanks for that.

You are a master of understatement.

As far as I can see, that is clearly an overstatement. Fred can make inane mistakes, like anybody else, but does so by plunging into certain subjects about which he knows very little with an air of authority. And when he is shown to be wrong, he is rarely willing to help resolve the ensuing confusion for the sake of both his credibility and the OP or other participants.

If you doubt this, I can provide several recent examples that should suffice to convince any independent expert.

If you are merely being kind, trying to say "he often knows ...", I am inclined to agree. But you do non-experts a disservice by promoting Fred to the status of "authority".

I've known a small number of people who would merit such exaltation, but Fred is most certainly nowhere close to that. To be an authority worthy of relying upon, a person must not only know a lot; they must know what they know and what they do not know and be honest about it. Fred completely fails to understand that, being more interested in ego maintenance than helping participants discover what they need to know to resolve their issues.

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--Larry Brasfield
email: donotspam_larry_brasfield@hotmail.com

Hi,

Does anyone have a 9V 1A transformer schematic? I want to integrate it into a project to run a disk drive. The smaller the better.

Thanks.

U.S.

design it

Here's an idea: buy 12 volt xformer with no center tap. Connect to it a small bridge diode rectifier rated for 2 amps or higher, and to that a large value capacitor such as 470 uF or greater rated up to 35 volts or higher. Follow that by a 9 volt regulator such as the LM7905 voltage regulator chip (may need a heat sink for that). The whole thing will take up very little space but will give you about 9.1 volts DC with pretty fair regulation and low ripple. This is pretty much basic, Electronics 101, kind of stuff.

Ron

Sorry, I guess I wasn;t clear. I need a schematic of a 9V 1A PSU. Such as the transformer, capaciters, diode.... It's an AC to DC. Would like a 120V and 250V version. I'm building a project and need to embed a PSU into the project. Hope this clarifies it.

Thanks.

better.

LMFAO!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

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Dave M
MasonDG44 at comcast dot net  (Just subsitute the appropriate characters in 

I'll try again.....

I need to build a power supply unit where I can take 120V AC from a U.S. home outlet and convert it to a 9 Volt DC 1Amp output.

120V AC 9V DC 1 AMP

---------> Converts to +-------->

---------> (-) ------->

Here is an example, but I need to build my own because I need to design it to fit exactly the way I need it inside my project:

Thanks

it.

Damn you're dumber than a rock- no clue in hell what the OP was talking about...

Thanks,

I have found this schematic online (not schematic symbol) and I think I could adapt it to supply a generic/home electronics 9 volts I need to run a generic floppy drive. I'll also be checking out that book you mentioned for future references.

Thanks for your help.

BTW, I did ask for a transformer schematic:

NOT a transformer schematic symbol: as some were confused. Sorry about that.

better.

I thought Larry was just f'ing with you in his first response, but he admitted otherwise. I figured that by asking for a trans shem, you meant PSU, but couldn't help but marvel that someone *might* actually want a trans schem (not symbol) as if they needed a schem to build one. It's like asking for a shematic of a wire to understand its operation or to make one.

I recently saw those two butt heads - oops! Let me rephrase that ( I gotta leave it in cause it was a funny mistake ) - "those two argue" and *both* were right - that statement made without me going back to nitpick little points that may have been incorrect, misworded, whatever. It's more like they discussed 2 different approaches and it was more a matter of their respective EE philosophies.

I've read more of Fred's EE info than Larry's and I haven't found any flaws.

You changed the subject line twice and I had to check google to verify continuity (no lost posts) Bad!!!

You should have posted to s.e.basics (seb) or alt.binaries.schematics.electronic (abse) and didn't. Bad!!!

I asked someone earlier today... "Is the google server down?" There's more friggin' PSU info and schems out there than I can shake a tree at.

Now go build your battery eliminator without frying yourself.

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Best Regards,
Mike

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You should realize that it was your original badly-formulated question
which started the whole thing and take responsibility for it instead

It's amazing how moronic & pathetic some people can be. Don't be upset at me for your failure to understand my question. I never even said a single thing to offend you. Obviously your lack of confidence and ability to deal with Fred's insult led you to concur that my question was the reason why you got attacked. Why did you give in to such sucker-bait? Reading your response exposed your weaknesses and lack of maturity. You are a socially unstable individual.

To the rest of the people in this forum reading this, I apologize for Larry and this uncalled for posting. I appreciate all your help and understanding that many of you at one point in your life, crawled before you walked. Thanks for your help!

In response to:

I believe that Larry was attempting to parody Fred's style. Don't take it personally. I don't think Larry meant any of that stuff.

If you use google to search on Fred's responses to posts, you will see that sometime he does insult people without providing any constructive advice.

It seems that some people really annoy Fred, and Fred let's his annoyance show. But he does seem to know what he is talking about when he talks electronics.

regards, Mac

This has been converted, via a process I will call the DERF transform [1]. This elision process conforms to accepted Usenet quoting practise with the exception that elided text is replaced by "[DERF]" and, where needed for grammaticality, short sequences within a '[]' pair are inserted.

[1. Application of a filter removing Dreck, Extraneousness, Redundancy, Foolishness.]

"Fred Bloggs" wrote in message news: snipped-for-privacy@nospam.com...

[DERF] 40khz amplifier thread?

I'm not sure what words you refer to. Can you clarify?

be taking up the challenge, (That was not English before the DERF transform either.)

If by 'called on it' you refer to your 3 posts several hours ago, I have not read them yet. I've always been the sort to save my favorite parts of a meal until last. However, if you have elected to actually engage in technical argument, I eagerly anticipate both the "challenge" and the result. However, from the volume reduction here effected by the DERF transform, I suspect that you have not undergone enough of a personality transformation to actually get to the technical merits with me. "We" shall see shortly.

[DERF]

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--Larry Brasfield
email: donotspam_larry_brasfield@hotmail.com