WHY YOUR PROJECTS WONT WORK!!

[Davor]

In my neck of the woods, we were often forced to keep a stock of used and salvaged components, and such stock is locally called a "furda" [foordah:]. Apparently furda's back

[Sean_Goddard]

Davor, if you EVER need a hard to get part, let me know. I'll source it and ship it to you. Screw ITAR and export bans.

[Alexismex]

Never had problem with Mouser for the integrated circuit , because i t is the base of your circuit , for resistor ,capacitor pot,
i bought china and make selection almost 50% 50% , sometimes 100% good because they are from mini stolen!!!

[Infamy]

Parts lists for boards not listing voltages. Is it that difficult? I don't get it. Maybe I should start designing stuff and not give the unit measurements, feet, inches, millimeters, meters, take your pick. Secondly this site has a large volume of information but the important stuff is well lost if you don't go to page 1052, its nutty.

Also I find it condesending to say to folks, no sympathy if your board won't work after you populate it when your probably dealing with a beginner following incomplete information. I know people go to alot of work put guidance notes together but they can be better. Mixed up parts lists come on, I need to set up a spreadsheet just to make sure I don't missing anything.

I think this is called feedback or is that flyback? 250 volts now where's that off to **** I don't know.

[GeoMax]

Hi Infamy,

I can understand your point. There are a few reasons why people do not write the "voltages" behind the components.

1. Usually in a metal detector circuits (except in the coil section) the voltages are very low and almost every component can take much higher voltages as you can find in a 12V circuit. For example. To an ordinary standard 100nF capacitor, you can apply up to 50V. Therefore, it does not really make sense to write behind every capacitor their max. Voltage range.
2. The circuit diagram gets to messy with all the unnecessary voltages written at each component.
3. The circuit designer only write the voltages to components where the voltage does matter.
4. Many times, it does not make sense to write it behind the component. For e.g. to write the max voltage behind a resistor does also not make sense at all. The usual voltage range of an ordinary 1/4W resistor is about 600V.
5. Some components like transistors have a coding. Here you need to check the datasheet for the max voltage range. Same for Zener diodes. Therefore, there is no need to write the voltage.
6. Often the circuit designer simply assumes that you know it.

There might be other reason why. Above are only some of them.

[Carl-NC]

Parts lists for boards not listing voltages. Is it that difficult? I don't get it. Maybe I should start designing stuff and not give the unit measurements, feet, inches, millimeters, meters, take your pick. Secondly this site has a large volume of information but the important stuff is well lost if you don't go to page 1052, its nutty.

Also I find it condesending to say to folks, no sympathy if your board won't work after you populate it when your probably dealing with a beginner following incomplete information. I know people go to alot of work put guidance notes together but they can be better. Mixed up parts lists come on, I need to set up a spreadsheet just to make sure I don't missing anything.

I think this is called feedback or is that flyback? 250 volts now where's that off to **** I don't know.

1. Voltages are usually implied by the power supply domains they are connected to. Ferinstance, if an opamp is powered from +/-5V and has a feedback cap then 10V would be a safe minimum.

2. Yes, it can be a challenge to wade through the forum. The "Tesoro Golden Sabre" thread has over 6000 replies and many other threads top 1000. I encourage people to start new threads, especially when branching the discussion, but often they don't. I don't have a solution to this.

3. We get a whole lotta beginners who (for lack of money or because they're illegal) want to build a detector and go treasure hunting. I've said it before, building a metal detector is a really tough way to learn electronics, and exponentially worse if you don't have the right equipment. But even experts have ways to mitigate problems. After almost 50 yrs of building circuits I still build them in stages: start with the power supplies, make sure they work; add the transmitter, make sure it works; add the preamp... etc. So many people build the whole circuit, utter a prayer, turn it on, and... uh oh, prayer didn't work. And then we (literally) get something like this: "Dear forum, I built the MaxPI circuit and it does not work, can someone tell me why?" It may sound condescending to say, "Do you know Ohm's Law? Do you have an oscope?" but often the answers are 'no' and there is little we can do.

[Hammerhead]

Well you are complaining of inferior ingredients What would a man like me from a third world country do? give an example capacitor 100 nano You have to buy at least ten piecesTo get the desired value

[kt315]

from a third world country do

i think if you get/dig a golden something from ground you must bring it in policy. or you county laws are so democratic?

[folharin]

I prefer to remove parts and components from old TV scraps, or other devices from established brands

[Sean_Goddard]

Moving to today, one can only hope that the Chinese military is running on this crap. If the Biden is stupid enough to take us to war, I think the US will anihilate China in under 5 minutes. Shame I like the Chinese, just NOT governments (of ANY nation).

[ivconic]

War is the worst possible condition in which a human being can find, by all standards.
I have the handicap of knowing it first hand.
That is why we must all unite against it.
I agree with your last words in the post, there is no such thing as a bad people, there is only a bad government.
And as for Chinese technology... it's much better and more advanced than you can dream of.
The problem is with us, because we constantly look at the prices and when we buy; we are looking to choose cheaper.
Don't forget that almost 99% of the things you have and use... are either made in China or Taiwan or Korea.
The Chinese make the best quality things in the world... but the prices follow that quality.
But we always look at the cheapest things on AliExpress.
Today there are no such differences in knowledge and quality as there were in the past.
But you need to separate things into classes, and that is the easiest in terms of prices.
I know the Chinese people. I have had direct contacts and experiences since the mid-1990s.
They are very hardworking, calm and decent people. It is always easy to cooperate with them.
I personally did not get the impression that they are warlike. Exactly opposite.
And on the other hand... Biden... an old man who doesn't decide on anything.
The main culprit for all the troubles in the world is the military-industrial complex combined with the bankers.
It is the group that finances wars and calamities in the world today.
We should be afraid of them. And they are here among us and not in China. They set up all our bad governments.
Today there is no difference in governments around the world, they are all bad. Same team, same interests.
"... I think the US will anihilate China in under 5 minutes..."
This is so ridiculous and naive!
Don't ever think that way. Because that's the Hollywood way of thinking.
If such wrong and unfortunate attempts occur; the whole world will be destroyed irretrievably... and us along with it.
We shall pray that it never comes to that. If not for ourselves, then first of all for our children and generations after us.

[ivconic]

WHY YOUR PROJECTS WONT WORK!!

My projects mostly work and they do it well.
And there is an exceptional cases when they don't work.
But then it is mainly about the human factor.
Either I made a mistake, an oversight, forgot to do something... or in very rare cases, the problem is in some bad component.
Yes, I had a case of buying an opamp with a counterfeit label.
And it took some work and effort to discover that problem.
There are such cases, of course. But they are rare.
Much more often, it is an intentional or unintentional error in the project documentation.
And often I, as a human factor, lose concentration, lose attention, rush, there are days when I can't do anything.
As I get older; I recognize such a day more and more easily from the morning and then I do nothing that day.
The success of my projects can be expressed as a percentage of 90:10 for now.
But the older I get; the situation is slowly sliding to the side of my failures.
I think it's a natural process and you have to come to terms with it.

[Sean_Goddard]

Wise words indeed Ivconic.

I was proposing that I hoped Biden wasn't counting on the dodgy component scenario.

Given some of the projects I have worked on, I have seen some incredible technology, WAY more advanced than what "civilians" ever see, but to detail them, I would be arrested.

[kt315]

Biden... an old man who doesn't decide on anything.

sorry, i do now want to be up here political matter,,, but Biden for me seems like Men In Black one. in some moments he comes out from room with correspondents like his battery did discharge(

[ivconic]

Biden... an old man who doesn't decide on anything.

sorry, i do now want to be up here political matter,,, but Biden for me seems like Men In Black one. in some moments he comes out from room with correspondents like his battery did discharge(