power

[slacker]

R.G. makes a good point. I'd add that the reason I wouldn't give advice is that I know just about enough to be able to safely deal with AC wiring, or at least I think I do, I haven't died yet But I wouldn't feel happy trying to pass that knowledge or lack of knowledge on to someone else.

[MikeH]

I'm picking up one of 2 things (no offense)- you sound like you either have no idea how to work with mains power, or you're not conveying what level of knowledge you have to any of us.  Either way, we're all going to suggest you don't play with mains.

When I started working on HV amps there was one thing I read amidst the pages of safety disclaimers that kind of put it in perspective for me:

Get your wife/friend/co-worker/etc. to take a CPR course.  Don't argue if they ask you to pay for it.

From the safety disclaimer at Aiken Amps

[El Heisenberg]

Well i guess it makes sense when you say i need training. I mean is it really like that!?! Is it really like walking a tight rope or jumping a motercycle or flying an airplane?!? I need to be TRAINED? What kind of things?? How many different operational procedurea do i need to ubdertake?!? "Wear rubber gloves and booties". Is it seriously this voodooish?? Like those guys who work on power lines from a helicopter?!? I really dont see why id need to be trained. TRAINED?!?

[earthtonesaudio]

If at first you don't succeed, skydiving is not for you.

[mharris80]

Well i guess it makes sense when you say i need training. I mean is it really like that!?! Is it really like walking a tight rope or jumping a motercycle or flying an airplane?!? I need to be TRAINED? What kind of things?? How many different operational procedurea do i need to ubdertake?!? "Wear rubber gloves and booties". Is it seriously this voodooish?? Like those guys who work on power lines from a helicopter?!? I really dont see why id need to be trained. TRAINED?!?

The way I see it, getting trained on the subject sure beats having to learn what not to do the hard way.  But that's just me.

[El Heisenberg]

You gotta be kidding!!! What skill do you need?? Its all physicall isnt it?!? Dont touch this, make sure these things dont touch, stuff like that?? What else couls there be. Is that ambiguous enough? What else besides those two things MIGHT be dangerous?? How would you hve me convey my skill level?? "im a level 4"

Ive built 25+ 9v pedals and several little 386 amp designs.

[El Heisenberg]

If at first you don't succeed, skydiving is not for you.

I havent done anything yet.  That makes no sense. Youve never done it either have you? No one is sayong anything!!  Is everyone really thinking in legal terms like that??

[jacobyjd]

Well i guess it makes sense when you say i need training. I mean is it really like that!?! Is it really like walking a tight rope or jumping a motercycle or flying an airplane?!? I need to be TRAINED? What kind of things?? How many different operational procedurea do i need to ubdertake?!? "Wear rubber gloves and booties". Is it seriously this voodooish?? Like those guys who work on power lines from a helicopter?!? I really dont see why id need to be trained. TRAINED?!?

Not sure if you're joking or not, but it's that kind of cavalier attitude that makes me nervous about some people trying to work with high voltages. As R.G. said, it's best to have someone show you in person, because there really is nothing like experience.

Look at it this way--I've pretty much always had the kind of knowledge that would allow me to put together a Small-Block Chevy V8 engine without hurting myself. The engine might even RUN for awhile on the first try.

However, it was only after my dad walked me through all the little tricks that aren't in the manual that I would be able to build an engine that not only runs, but at top performance for its specs and with long-term durability.

All that to say, sure, maybe you could build something that works without killing yourself, but without the knowledge of how your tiny, unforeseen errors could affect you (or your band-mates, affect flammable items in an out-of-code venue...) in years to come when you mess with AC mains without a little patience.

[MikeH]

There are guys who work with mains their entire professional career and then shock and kill themselves days from retirement.  And as experience decreases so do the chances of survival... exponentially.

If you have to ask "what could go wrong" them you just don't know.

No one is telling you 'what could go wrong' because the possibilities are endless, and have an opposite relationship with how much you actually know what you're doing.  IOW, the less you know, the more there is that will likely go wrong.

[MikeH]

unforeseen errors could affect you (or your band-mates, affect flammable items in an out-of-code venue...) in years to come

Exactly.  5 years from now you, or a friend, or some poor sap who buys your amp at a pawn shop can go to flick it on and- pow.  Toast.  Human toast.

[jacobyjd]

Ive built 25+ 9v pedals and several little 386 amp designs.

Additionally, with regard to the above statement, I'd be curious to know of any reports where individuals have died from being shocked by a 9 or 12v DC line.

I bet I can find more news stories on individuals being killed by mishandling mains.

[mharris80]

High voltage in action. 

*WARNING* This link is not for the squeamish, faint of heart, etc.  If you aren't prepared to watch somebody die, don't click on this! (MNBSFW)
http://www.evilchili.com/videos/30711/Never_Grab_Electric_Wires

[JKowalski]

ACCIDENTS HAPPEN

I will say this: Go ahead and try mains voltage. BUT: Make sure you know EXACTLY what you are building (as in HOW THE CIRCUIT WORKS, and WHAT MIGHT GO WRONG) , make sure you know that it will work EXACTLY as you want it to, and make sure you know EXACTLY what wires are safe and what wires are dangerous. Make sure you test out your device in a empty, clean location, such as a cleared tabletop. Make sure you stay by the cord when you plug it in, so that if anything goes wrong you can immediately remove it. Check every relevant location on your construction with a voltmeter, to confirm it is all working as planned. I'm sorry if this seems like too much, but every person I know who works with mains takes all these precautions, and sometimes even more. If you have a choice between death and a little bit more work, a little bit more work sounds better, huh?

Its kind of funny that you mentioned rubber gloves - that would be an excellent precaution to take! I should probably find some to use myself. If you do go through with this, take your own advice on this point! Even if you do, you can't ignore all the safety tips because you are "invincible". Wires can poke through the glove (they are sharp), or something totally unexpected can still happen. But It will greatly reduce your chances of getting shocked.


-   Another tip. If you touch a high voltage line, your hand typically clenches up from the shock to your muscles. Be careful not to touch anything by grabbing it first, because if it shocks you, you wont be able to let go. Use the back of your hand. Of course, a voltmeter check before touching things is always the most sensible thing to do. Don't try to touch anything that might have mains or anything high voltage. This is just a useful bit of knowledge to know.

-   Mains voltage is not ALWAYS dangerous. You can definitely touch a mains line and be perfectly fine. You sound like you are in disbelief about our warnings, and yes - some of them are quite dramatic. BUT THEY ARE THAT WAY FOR A CAUSE. It is those few cases where the situation is perfect for a fatal accident... If you take ALL these precautions, the chances of this is practically nil. But if you don't you seriously are gambling with your life.

-   IF YOU HAVE ANY CAPACITORS CONNECTED TO HIGH VOLTAGE, DISCHARGE THEM. From what you are describing, it doesnt seem like you will have to worry about this. But, it is another thing you need to know - capacitors will be just as dangerous as mains after being connected to it or any high voltage source. Touching them can also kill you. Discharge them by using some kind of insulated tool made of two wires in series with a high wattage resistor. Put the two end of the wires on either lead of the capacitor. This will slowly neutralize the voltage differential between the two sides of the capacitor. If you dont use a resistor, you have a enormous spark, quite deafening,  and quite dangerous.




Dont, I repeat DO NOT mistake my post for a change in tone from everybody else - I stand completely by what everyone else has said here. I'm not in ANY WAY encouraging you to just forget about what this forum has told you and to "do it your way". I''m sorry to say this, but you do seem like you are a little inexperienced with electronics. Building pedals from schematics does not mean you have any knowledge of electronics. Sure, you might learn some along the way, but you can easily build 100 pedal clones and still not know what a capacitor is. As others suggested, please do some reading. It is as I said earlier, you need to know how the circuit works before you go ahead. (and what might go wrong!)

[El Heisenberg]

thanks the last few posts are the kinds i was tryin to get. A scenario where 5 years from now somethin could come loose and i would get shocjrd or the place isnt grounded right or something.  And the bak of the hand thing is good too. On this amp there are only two connections i need to make to the transformer and the ac chord. Thats why it seems so strange that everyone is so certain i dont know enough to pull this off.

About the rubber gloves. If im wearing two pairs, thats safe isnt it?? I mean, this will for sure protect me unkess there is a hole in the glove. But i think i can handle it without poking a hole in the glove. Seems easu to me.

[El Heisenberg]

Also the schem i have includes a fuse. This should help too right? Also the 4 1n4001 diodes. Its from craig andertons book.

This amp is dirt simple. Im starting at the bottom.

[jacobyjd]

If you're the same heisenberg who insisted that he was above posting debug voltages, then I don't really expect you to listen to all of the intelligent suggestions above asking you to be patient and build some more knowledge, rather than diving right in.

However, given what I can observe from your attitude about the whole idea, as well as your attention to detail as displayed by your use of grammar when posting on this board (if English is not your first language, then I can understand, and no worries there), I stand by my suggestion that you stick to low-voltage amp designs until you have a better hang of things.

Really, what's keeping you from trying something like Rick's Murder One? That runs on 12v and gets a B+ using some nice tricks--it's less likely that you'll kill yourself that way, and from what I hear, it sounds great.

[JKowalski]

Yes, those are the only connections you need to make. We are going crazy over this not because it is complicated - complexity doesn't really matter in this case. You can have an accident, even with the simplest circuit.

The fuse needs to be in series with the "hot" wire from the wall. You need to figure out how many amps your circuit will draw as a maximum, and then choose your fuse at a decent level above that measurement. It will break the hot wire connection if the amp draws too much current.


http://us.st.com/stonline/books/pdf/docs/1707.pdf  (Take a look at the "full wave split supply rectifier")

http://www.play-hookey.com/ac_theory/ps_elements.html  (read the "power supply fundamentals" series.)

Just search around and read a bunch of relevant sites from google about "rectifier power supply", or more specifically "split power supply rectifier".

KNOWLEDGE IS POWER

[El Heisenberg]

i dobt hve a computer. YOUBtry gettinf everything perfect on an iphone! I take alotnof time posting with this thing!

Debug voltages wouldnt have helpe in that case. It was breadboard. If every IC pin got 9v and 4.5 where it was supposed to, why mention them?

The reason im building this is because it AC. I know theee ar plenty of ither designs. Cmon.

Anyway if your not gunna post anything besides "ur stupid" then stay out, thank you.

[El Heisenberg]

Yes, those are the only connections you need to make. We are going crazy over this not because it is complicated - complexity doesn't really matter in this case. You can have an accident, even with the simplest circuit.

The fuse needs to be in series with the "hot" wire from the wall. You need to figure out how many amps your circuit will draw as a maximum, and then choose your fuse at a decent level above that measurement. It will break the hot wire connection if the amp draws too much current.


http://us.st.com/stonline/books/pdf/docs/1707.pdf  (Take a look at the "full wave split supply rectifier")

  (read the "power supply fundamentals" series.)

Just search around and read a bunch of relevant sites from google about "rectifier power supply", or more specifically "split power supply rectifier".

KNOWLEDGE IS POWER

Fuse specified is a 1/4 or 1/2a fast blow fuse.

[MikeH]

You can have an accident, even with the simplest circuit.

People still electrocute themselves screwing in lightbulbs.

Anyway if your not gunna post anything besides "ur stupid" then stay out, thank you.

No one has suggested that "ur stupid"; maybe just a little uninformed, a little too confident, and unwilling to acknowledge the danger that your lack of experience and know-how presents.