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MP
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Posts posted by MP
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I thought jpg were the smallest package because of compression? Not so?
MP -
It is as LDanielRosa has said, but allow me to add some comments since this is an International forum.
Where to put the fuse depends upon the mains. Usually, the mains will have a hot lead or leads and the other is considered common. For example in the US and Japan 120 VAC and 100 VAC, the black is hot and the white wire is a return or common. You will find that the circuit breakers on 100 VAC, 120 VAC are only on the black wire. This is because if you break the circuit on the common while the other is still connected, then you will have more of a danger as the circuit is live with no ground and looking for a way to complete.
If your mains are 220 VAC, then the method described by LDanielRosa is perfectly correct as both wires are hot. Using only one fuse would still leave you with a hot circuit. You want to be sure there is no problem with the ground return path in either type.
MP -
ante, I have been researching this question since you and I had several discussions on the matter some time ago. You will have to have "some" resistance. You cannot have a direct short in an AC or DC circuit without ending up with a problem. However, what I have found is that these circuits are working on a different principle.
1. The quick switching action is not considered a direct short such as any other alternating current that crosses the zero path over and over again. Please note that some digital circuits on the market work entirely on the principal that switching capacitors which are connected to ground on and off with different duty cycles makes a variable resistor which is digitally controlled.
2. The circuit is providing resistance in other ways. There is also resistance in the transformer as well as the capacitive/reactive resistances in the circuit.
With this in mind, one does not need added resistance if the circuit is designed correctly. Therefore, I will have to say that both methods can be correct.
You will notice that this is a different view than I had when we discussed this before. As I am researching this more, I am leaning more toward your view on this, since I can see where the resistance comes from.
Also, I have had to brush up on what I know in this area of electronics as I am now working more with solar design than I have been before.
MP -
Ante, You make a very good point. One that is not observed very often. When dealing with power inverters, a lot depends upon the transformer at the output. In Aaron Cakes original article, he spoke about using a microwave transformer and re-winding it. Anyone who went to Radio Shack to get a small off the shelf transformer would have problems in such a case, if you need more VA.
audioguru, once again, I want to remind, this thread has been unlocked so that a way to make the project work can be discussed. Not to keep pounding on the project or point out why it might not work.
MP -
Siddarth, I am sure there is a tool in existence like what you have described. Yes, this battery/LED circuit would just be a basic continuity tester for one leg of a non powered circuit. There are a lot of variables one would have to consider to go beyond that. Interesting, though.
MP -
Ulman, there is an excellent 555 timer tutorial here: http://www.meridianelectronics.ca/gadgets/555/555.html
Here is one of the examples, a 10 minute timer. Hope this is helpful to give you some ideas.
MP
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Nettron, thanks for sharing. ;)
Do you have a picture of the prototype? I think others would be intrerested to see it as well if you do.
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The metal detector approach will tell you there is a wire there, but it will also tell you there is a nail or a water pipe there. It will not tell you what the current of the wire is. For this, you will need an inductance meter circuit.
MP -
audioguru, this is not rocket science. This is the same method used by even the car industry since Henry Ford was building cars. For example, if you are building a hot rod and you have to move the battery from the front of the car to the trunk, you use a larger cable. You do not go out and buy a 24 volt battery. ::)
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sure, then it only becomes a matter of money ;)
With unlimited funds, anything can be produced. The circuit would be much more complex and unneeded for most applications and out of budget for most hobbyists.
MP -
This subject was discussed briefly last December here:
http://www.electronics-lab.com/forum/index.php?board=13;action=display;threadid=125
I posted a simple schematic. You would need to add some type of meter to the circuit. As drawn, it will only detect.
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The resolution seems fine. When you click on it you get a larger picture.
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Hotwaterwizard,
Is there a particular program or website where you have had better luck than others for finding data sheets?
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It is ok to disagree. But that is not what I said. As I look at my last post, I agree it is not real clear, nor was it worded in a way to get the meaning across.
What I said was that the circuit would "require" more current. Thus he would want a PSU rated at higher watts. Added was my suggestion of a larger gauge of wire. This is what actually reduces the resistance. For example 24 AWG wire has a resistance of 84.2 ohms per 1000 meters whereas (larger)16 AWG wire is only 13.2 ohms per 1000 meters (as an example, not that this length is even considered). Point is, as you increase the gauge, you have considerable less resistance. However, you also need more current. Sorry, I do not have a measurement for copper pipe or I would also post it as per your earlier suggestion.
But as funny as that might sound, if you had enough current to power it, yes, you could use the pipe. ;D
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Kasamiko,
If you can put the bmp format in a zip file or e-mail it to me, I can retrieve it and reformat the size. I do not have express schematic on my pc.
MP -
please restrict comments to positive comments on how to make this work. The author claimed on his forum that it worked for him.
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Thanks!
I hate having parts in the bin with no data ;D
I even tried an NTE cross reference for it on their website.
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audioguru, I looked at the author's forum and it does not look much different than threads on this forum. There were those who claim the inverter works and several who have problems with it. It could be due to instability of the design, the knowledge level of the project builders, mistakes in the schematic, or any combination of these.
Before we will be able to improve on this, someone has to decide they want to work with it on the bench. We need verification that it will fail and then to decide how to improve it.
We might even want to make contact with Aaron Cake to involve him in this.
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I went back through the posts and found the zapco post. There are quite a few schematic posts in this thread. You are trying to redesign an amp that is already on the market? Build a new amp? What is the purpose of this subject?
This thread does not seem to have any direction.
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siddharth, a continuity tester is not usually used to check through all components such as resistors and capacitors. This is a different device. A continuity tester is usually used to check that a non powered trace on a pc board goes from point A to point B with no interruption. Even when components are placed on the board, this works because electricity will take the least resistive path. As with anything, there will be the one occasion where it does not work.
MP -
Nitpicking.
I have lighted LEDs on my bench with a AA battery is why I mentioned it. So if you cannot get this to work with your LEDs, use two batteries. It is still a simple circuit.
...and, yes, as I mentioned, it will depend a lot upon the circuit that it is used on.
Note that the original post did not give any feedback to my comment, "You really have not given enough information about the circuit to return with much more than this." So, I will stay with my original comments.
MP -
audioguru, the regulation of the PSU will match the voltage. You need more current to allow this due to the added resistance of the wires. This is why you now see computer power supplies going up to 500W when they used to be only 230W.
Voltage is only potential. It is the current that causes the circuit to work. If you have 1,000 volts and no current, a circuit will not do you much good.
Now, getting away from the theory part of this subject, I have experimented with this myself. One of my older computers gives me a bench power supply from the plug through the back panel.
I liked your copper pipes idea, but thought that it might be a little extreme in this case. ;D
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I do not have a problem with connecting, but I have noticed delays between pages at times. No error messages. I had assumed it was high traffic times on the server.
MP -
One alternative is to attach it as a zip file. You will not be able to see it in the post, but when you click on it, the picture should be viewable. There might be a better suggestion, but I cannot think of one.
MP
Night rider scanner
in Electronic Projects Design/Ideas
Posted
yes, audioguru, could you post an original design for others to view?
MP