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MP
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Posts posted by MP
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You are really a paranoid person, talking about secret emails and replacing projects. The inverter project that I corrected was on this site long before you first appeared. It was still on this site when I fixed the lines which were drawn badly by the author. You should seek professional help instead of trying to instill unrest on this site because you have a beef with me.
Here in this forum you are doing the same thing that causes me to delete your posts in the forums that I moderate. Your posts have nothing to do with Theory or anything else. Just bitterness, grumbling and insult. I didn't pull your precious audio amp inverter off the website. I don't even have access to that area of this site. But you already know that since you used to be a moderator here and lost it. Smoke and mirrors. Just trying to get people angry to help your cause. Why don't you go peddle this crap on Aaron's website where they will take it.
MP -
Ante,
Projects Q/A is for members who are building a project who need help. Posts not helpful to building the project in the original post do not belong there. Discussion of the theory behind the articles belong in the theory section. After many theory discussion posts, the author of the original post starts asking me questions directly through PM and then through email. Audioguru is only driving people away from these discussions and you are helping him do that when you take up his side. Please allow me to take care of this without feeling the need to intervene. I am not out to get audioguru as you have been saying. I am only trying to keep the forum cleaned up. I apologize if I rubbed you in the wrong way in doing so.
MP -
Mik3ca,
First, you should understand that I did not design this inverter. I only corrected the mistakes in the schematic. There were lines that were crossed and connected, and decimal places wrong in values. They were simple fixes. The design is still the work of the original author.
Secondly, note that you do not need the current limiting resistors in a switched application such as an inverter. Such resistors are needed for a linear amplification such as an audio power amp. Look at the many designs all over the web for a square wave inverter circuit and you will see they are all missing the resistors. Square wave inverters are all basically designed the same. There is nothing different about this circuit than the many all over the world presently in service. I have actually had emails telling me the one that audioguru helped design works much better if the power resistors are removed from the circuit.
Note that audioguru admits that he has never built an inverter.
This is why I moved this thread to the Theory section.
BTW...it is my understanding that Rhonn's design is not deleted. It is just being moved to it's own page. Audioguru is making a big deal out of nothing.
MP -
Ante,
I didn't delete a project. This is not about liking or disliking audioguru. As far as removing the posts, I had problems moving things to the theory area, so I apologize for your post that was lost. It was not as easy as I thought it would be to do.
Syed is making the project in his first post. I am not tolerating audioguru's continued posts telling him his project will not work or that it will blow up because he is not building the one he designed. That is not helpful. Audioguru can discuss the theory of what he thinks works and what he thinks will not work in the theory discussion area. He has already stated that he has never built an inverter. That only leaves him theory discussion. I do not want to cater to theory discussion in the Q/A forum.
By the way....who has threatened you? That's not right. No one should be threatened here.
MP -
Ante,
There were some lines connected wrong or crossed and the decimal of the cap and resistor for the clock were off. Very minor fixes. I cleaned it up and uploaded it.
As far as the "open forum" questions, no, Projects Q/A is not an open forum. It is reserved for questions and answers to get help with a specific project. In order to keep the threads usable, I try to be very strict to keep all other conversations and/or grumblings out of this forum. We have plenty of forums on this site. Theory can be discussed in the Theory forum, general discussion of electronics can be posted in the Chit Chat area. Anything that does not seem to have a forum can be posted in the General forum and feedback to the site can be posted in the feedback forum. I don't think I am asking much to have this area reserved for those who are building projects to get help with their work. I seem to get a lot of "don't build that...build this" posts when someone asks a question here. That is not what the "Projects Q/A" forum is about. When members contact me through PM and email to get the help that they can't because of audioguru's grumblings and multiple off subject posts in this forum, I decided it is time for me to put an end to it.
MP -
Theory discussion regarding inverters has been moved from this thread to the theory forum
MP -
I have used both Lexmark i3 and X1100 series. Just print on best quality black and the transparency looks good. I have actually retired the i3 to the workbench since this model runs the paper straight through without bending it. I hope to get some time to examine it and see if it is possible to convert it to accept pc boards instead of paper. I hope to be able to print directly to copper clad if I can find a suitable ink to fill the existing cartridges. Take a look at one of these. You will see what I mean.
Take care!
MP -
idevices,
That used to be the case. I did exactly the same many years ago. However, Inkjet technology has changed. You can use the darkest available setting on a high resolution inkjet and it is much darker than laser printer transparency. I think the problem is not the technology used, but is the printer used, in his case.
MP -
You should post your schematic and board layout if you have it. If you know the specs on the steppers, please also post that. All of this information is needed to properly answer the question that you are asking.
MP -
As additional information for those who were interested in the serial port information:
The Lynx technology transmit and receive chips use 3 Ma typically and actually 1.5 mA on average. Since I would never take up two ports on the computer to run one device, I would look for a low current consumption device such as this.
MP
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...of course, the answer is yes. He can certainly use the USB power pins as a power supply. There is no association between the power pins and the data transmission lines. They are just on the same connector so that they can power the device connected. Current limiting with a resistor is a good idea since you are connecting to the Computer internal electronics.
MP -
hello guys ..
iwant to know that if transformer with 220V/15kVA 1A is same as 220V/15kVA 5A ? ???
No. It is not.
MP
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You can actually tap the voltage you need from the serial port unless you need a lot of current. AtMega chips only require micro-amps. It is the additional circuitry that requires additional.
Here is a schematic of a 5 volt tap from the serial port.
MP
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yep....later there was a merger. Then they went out of business altogether.
MP -
I clicked on the"notify" button on the main moderator's board page. This way, I get an email link whenever someone posts anything in this forum....before I figured that out, I did it the same way as hotwaterwizard.
MP -
The original design did not even use a pot. I'll stand by my first comments since I know how this will effect some devices that might be plugged into it.
If you can't find the panasonic pots, try the clarostat 585 series. They are available at Newark Electronics ( www.newark.com ) as part number 585DX4Q25F103ZP at $2.48 each. No waiting. Or just build the original which did not add a resistance path to ground ahead of the input cap. In this case, you rely on the volume control of whatever is plugged into it.
Part of your parts availability problem is due to the pot having an on/off switch. Another alternative is to purchase an audio taper pot without the on/off switch and use an input jack with an additional leg that sits against the ground barrel of your cable. Attach the ground of your battery to the additional audio input lug which is only grounded when you have something plugged into the unit. This will also keep you from losing batteries if you accidentally forget to turn it off when you disconnect. (Example below).
This is easiest if you are using a mono input. You can use a stereo jack. However, if you will be connecting two of these circuits to a stereo jack, you can still get jacks with additional connections in them. They are just not as common.
MP
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The volume control doesn't need to be 10k. It can be any other value up to about 100k.
That would depend upon what's in the electronics of what is connected to it... ::)
I would suggest that you use the correct value and just get it from another source like mouser.com or one of the surplus parts houses.
When you start changing the resistance of inputs and/or outputs, you sometimes end up with strange problems that are hard to determine the cause of. Keep the correct values.
MP -
Any one have any experience with PICs?
Yes.
Try posting your PIC questions in the microcontroller area. You aren't really discussing the diode tester project, so you are in the wrong area.
MP
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Syed,
Please check your email.
Take care!
MP
MODERATOR EDIT: The original project has been corrected in the projects section. -
Hello Herman,
You will not be able to have a direct conversation with the author of this circuit. The original author is "Smart Kits", but it is a very old kit design and lacks modern principals and newer chips that were offered after the initial design. There are new chips on the market that would do the job much better. However, the point of this area is to discuss what is already here. This thread deals with questions to build this project and questions and answers anyone has regarding it.
Audioguru has suggested a lot of changes, so you might mention which version you are suggesting additional changes. Note that "Smart Kits" are not real elaborate designs. They are simple kits to help beginners learn something about electronics. This thread has turned into a major re-design fiasco instead of simple questions and answers for those who are trying to make the kit. I would have prefferred that those who wanted to discuss a re-design would have taken this subject out of "Projects Q/A" and made a topic in the appropriate area. This approach would have been more beneficial to other members. If I ever see myself having lots of spare time, I might move posts around so that it is more organized in this way. I get lots of emails and PMs grumbling about how this topic is no longer helpful to one trying to build the project and that it is much too long to read through. Perhaps we should open a new forum named "re-design" ;D (That was a joke, AG)
MP -
vivek,
we do not have a project on this site for such a large consumption. Here is a website that fully documents a 2KVA that has a modified sine wave:
http://www.technology.niagarac.on.ca/people/mcsele/i2k.htm
This project uses the microcontroller as I had described above, but don't worry if you have never programmed a PIC. Everything is on this website, including the code for the micro. I think you can even contact the author with questions.
MP -
The way I read it is that the %duty at Q and Q_bar will be 50% and that the signal at the oscillator output is not guaranteed to be 50%
AN920: It says a 50% duty cycle is not guaranteed. Period. It does not say that you get a "perfect 50% duty cycle" anywhere....which is what audioguru says the datasheet says.
Dear MP....
What is the technique to generate a set of sinewaves (of opp phase)?
Is it the regular oscillator?
vivek: to get a sinewave inverter, you would use a different technology. You cannot use a sinewave and amplify it like a squarewave. Too much heat loss. Many manufacturers use a microprocessor to digitally simulate a sinewave in a switch mode.
MP
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Amazing....since I posted a picture of part of the datasheet. Where did you find the word "perfect"? I performed a search of the pdf and found 0 instances of the word "perfect". I also performed a search for the word "exactly". Also, there are 0 instances of this word. However, I do find a statement in the data sheet that says a 50% duty cycle is not guaranteed. You have a pretty good nack for reading things into a data sheet that do not exist....of course, I think I have made this same statement to you several years ago..
oh, by the way...what you explained was how the IC uses a digital divider to produce perfect compliments of the two signals Q and Q-NOT...Not how it produces perfect square waves. There is quite a difference. I know I am wasting my breath to explain all of this to you, but there are others who might like to know.
MP -
In 1982 it became "Computer and Electronics", then went out of print in April 1985. Many of the editors and authors moved to a new magazine named "Electronics Now". Many readers thought that this was just a new name for the magazine since the authors names were familiar.
Look for "Electronics Now" for the same type of articles that you saw in "Popular Electronics".
MP
Argumentive members
in Moderator's board
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I think mixos should reply on the number two issue. If you are getting threatened, he needs to contact those members and warn that he will block them from the site. I have not seen this problem and was not aware that it existed on our site. I have seen many on the site mention god, but I am not bothered by anyone being religious. I actually have the avatars turned off because I do not like to look at some of them. I don't know what pictures anyone uses.
MP