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Blinking heck, you've got good eyesight, I had to zoom photo right in, would it make it easier if I desolder this & two retifiers as it looks like they have numbers too
Man, that was a nightmare, gonna need a microscope if that's anything to go by **broken link removed**
late for work, good job I work flexi time **broken link removed** but there was no way I was giving up, unsoldered, took five million photos & zoomed in until I could see em, so we have as follows:
left hand side of choke, by transistor: Rectifier:
LB
IN5819
R6, righthand side of choke: Rectifier:
IN4007
UPM
& diode:
IN4148
5T
I'll have a go at working out all resistors tonight **broken link removed** see you later guys
so onto resistor coding, then we can do schematic to see how this worked **broken link removed**
So what are the tiny blue lines by tolerance band? on resistors, do you want a photo?
R1: Brown/blue/red-gold = 1.6K 5% t
R2: Red/Black/Red-gold = 2.0K 5% t
R7: Red/Green/Red-gold = 2.5K 5% t
R3: Brown/Voilet/Grey/Brown-brown = 1.780K 1% t
R4: Red/Red/Gold-gold = 220 ohm, but band is gold & chart only says brown???? 5% t
R5: Voilet/Green/Black/Red-brown = 75K **broken link removed** 1% t, is that right **broken link removed**
R9: Brown/Red/Black/Black-brown = 120 ohm 1% t
Well, as it turns out, I got a little too enthusiastic about deciphering the workings of that PCB.
I made the mistake of asking the forum to help me "reverse engineer" the the board and was immediately reminded that kind of activity is just, well, a bad idea. It is just another form of plagiarism.
And I agree.
There's no harm, I don't think, in trying to figure out how something works. But that's a private affair, not meant for public discussion, which is where I went wrong.
Anyway, what I did find out was that, Big Surprise, it's some kind of a regulator. A current regulator, best I can tell. The schematic I drew lead me to that conclusion, but the effort was less than gratifying and, frankly, not worth pursuing.
Truth is, it's better to learn about something by trying out your own ideas. which is where you started. Putting together the parts and then seeing what happens is really the best teacher.
Anyway.
A resistor resists current. That's it. nothing more to them than that.
A capacitor is, literally, simply two metallic plates separated by an insulator. But their uses are myriad.
There is no direct connection between the two plates. In its most basic form, a capacitor will not pass DC. But it will pass AC. That's because electrons can pile up on one plate, causing a "potential" difference between the two plates that electrically mimics AC. Thus they are useful for transferring, without a DC component of a signal, the AC that needs to pass on down a circuit's path. And they're capable of storing electricity, not unlike a battery
In its most basic form, a diode is a device that only conducts in one direction. Rectifiers are diodes also: same function.
This is a very useful attribute when you want to, for instance, turn AC into DC. And, not unlike many other solid state components, there are many different ways to construct them. This in turn gives them many different ways of behaving in a circuit. Their uses as remarkably diverse but in essence, they all involve the basic function of a diode: let juice flow one way, and not the other, except in some cases.
As you can see, a discussion of diodes can get out of hand quickly. For the moment, think of them in their basic usage.
A transistor is, basically, a diode with a control element. They have a variable behavior with their ability to restrict large current flows with much smaller current flows. This makes them, amongst many other things, very good at Amplifying signals.
Well, as it turns out, I got a little too enthusiastic about deciphering the workings of that PCB.
I made the mistake of asking the forum to help me "reverse engineer" the the board and was immediately reminded that kind of activity is just, well, a bad idea. It is just another form of plagiarism.
And I agree.
There's no harm, I don't think, in trying to figure out how something works. But that's a private affair, not meant for public discussion, which is where I went wrong.
CBB after looking up what that actually meant.lol
You were helping me with a good heart & for that I thank you.
I feel a proper response is in order to clear any misunderstandings here, not really suited to a phone, I'll respond properly to that in the morning.
Alas, as forum users, we take guidance from those that know better with good grace & not take it as an attack on ourselves in any way ;-)
Hope you enjoy your cuppa, relax & enjoy it, then I can carry on my studies of components I the morning
So that apart, more interestingly, how did my resistor ID do?
Have I got the hang of understanding banding correctly now
The small child in me is excited that we can start work on my project now, the grown up in me would love to study more
R1: Brown/blue/red-gold = 1.6K 5% t
1. R2: Red/Black/Red-gold = 2.0K 5% t
2. R7: Red/Green/Red-gold = 2.5K 5% t
3. R3: Brown/Voilet/Grey/Brown-brown = 1.780K 1% t
4. R4: Red/Red/Gold-gold = 220 ohm, but band is gold & chart only says brown???? 5% t
5. R5: Voilet/Green/Black/Red-brown = 75K 1% t, is that right
6. R9: Brown/Red/Black/Black-brown = 120 ohm 1% t
1. Gold is 1%
2. Ditto
3. None or brown is 10%
4. Sure looks like red/red/gold, then gold so pretty sure it's 1%, but since it looks like a 1 watt (as do R3 and R7), and appears to be in a high current path of the circuit, I'd say 220 ohms and 10%.
5. You know, it may be that the gold is actually a shiny brown. Reason I say that is because it would be odd that they used 1 %ers on a board of this sort. Who knows.
6. Following that thought these may be of European or UK manufacture; perhaps there are subtle differences in the coding. That's why R9 has me thinking it's 1200 ohm.
Never really seen resistors coded this way. I take that back. Do remember seeing some in the Navy (40+ years ago). Weird'ed me out.
NOTE: I've always made it a policy to check any resistors I'm actually going to put into a circuit with an ohmmeter first. Tolerances of resistor values only really start to matter when you're trying to achieve tight RC (resistor/capacitor) values in oscillating circuits, but I check'em anyway.
Overall you did good, grasshopper. If it makes you feel any better, to this day I keep a resistor color code chart real handy. I also have a come and go problem with mistaking green for blue (vice-versa).
An ohmmeter is my friend...
BTW, don't trust checking a resistor's value in a circuit: it is most likely that it is in parallel with another component (that has resistance as well) and you will not get an accurate reading. Only test the resistor all by its lonesome.
Sometimes there's as much art as there is science in the field of analog 'tronics.
Well, as it turns out, I got a little too enthusiastic about deciphering the workings of that PCB.
I made the mistake of asking the forum to help me "reverse engineer" the the board and was immediately reminded that kind of activity is just, well, a bad idea. It is just another form of plagiarism. And I agree.
I've been itching to reply to this all night, after looking up what plagiarisim actually was & seeing tvtech's reply, I seem to be under the impression that the idea was taken that I have somehow got the urge to copy this circuit or even worse pass it off as thou it was my idea.
Lets start from the beginning & hopefully you,tvtech & anyone else reading this will understand, to be honest, I'm sure you already do **broken link removed**
I already see what I want to achieve in my head, some might think it crazy, some might think it possible, some may consider it a waste of time, but more importantly it will allow me to learn for myself about what is possible & what is not.
I take it by now you realise that I'm not after a solution, hence us going back to beginning of this little project. Anyone can have a idea, putting it into practise is another thing entirely.
I joined the AAC forum full of new enthusiasm, there were some really nice guys on there, bit like here really, but my thread was brought to a halt as *automotive* is not discussed on there.....oh, ok then I thought (I'm happy to work within rules of forums) but it seemed a shame when you suddenly realise life is passing you by, you finally get the urge to learn something new to be told it isn't the done thing.
The really sad part about this in my eyes was the very fact that all my gadgets already work on my mototbike, I just found an excuse to learn, that would keep my interest, where I would end up with a sense of pride for building something that I could use at the end of it **broken link removed**
Did I let this get to me, maybe if I was honest it did crush me slightly but rules are rules & I'm sure those who make them have their reasons & it's not for me to argue about with them, I want to make friends along my path of life, not wind people up.
Anyhow I then found this forum, it was my own fault for not explaining my desire to learn right from the start, I asked how to do something & there you were with a solution. I'm not joking, I could have wept, I nearly gave up on this new idea of learning electronics, this was my low point, but I put it to you that I wanted to actually learn the whole concept of all this & I can never put into words how grateful I was when you actually realised what I was trying to achieve, for this I will forever be grateful **broken link removed**
So there we have it, I got to feel like a young kid again, full of Q's of this new & exciting world of electronics.
To be honest, the idea of copying this circuit would be pointless, I could buy one of these for less than an hours pay & would guess it would take me at least two days to make, in money terms, I reckon I would lose about £150/$237.54 per circuit **broken link removed**
Anyway, what I did find out was that, Big Surprise, it's some kind of a regulator. A current regulator, best I can tell. The schematic I drew lead me to that conclusion, but the effort was less than gratifying and, frankly, not worth pursuing.
Sorry, maybe I should have explained better, I know it is some kind circuit to stop overload, it is also limited with a 1A fuse & it has an output V reading that flutuates within half a V when plugged in to a car socket.
The purpose of working on it was to understand components & how they work. I'm sorry that you feel like you have put a lot of effort into something that seems pointless, I can only hope you can see what it has taught me so far.
From my original idea & with this little pcb, I have learnt the basics concept of electricity, I'm starting to understand resistor banding & more importantly where that decimal point goes (it was a lot easier for me relating to this pcb than working on theory) what components actually achieve & component ID & there is also a schematic that will actually make sense rather than just a lot of lines & numbers that mean nothing if you don't understand them, this may not seem a lot to those that already know it, but to me it has been priceless
I know I have a lot to learn & I see working on pcb no different to a student studying an already known circuit, maybe I'm wrong **broken link removed**
Anyway, if your happy to stay with me on this, I'd like to actually try & finish schematic the way I understand it & for you to check it if that's ok, then I can build this onto my list of what I've learnt so far, not because I need to as I have little use for a 1A reg in my project or because I want to lose £150 per part selling them, just because I will be able to relate those lines & symbols to something that actually makes sense
Well, I hope that covers it **broken link removed**
Truth is, it's better to learn about something by trying out your own ideas. which is where you started. Putting together the parts and then seeing what happens is really the best teacher.
oh boy, I can't even begin to tell you how much I wanna get there, the urge to ignore some aspects to getting to play is like having a itch that won't go away, but I know I will have totally missed my real goal of understanding which is what kiss was saying, as I say, my toys already work, this is just a learning excercise **broken link removed**
Can we go back to learning now **broken link removed**
On that that note. I think it would help your sojourn here in the classroom of 'tronics if you could find an old tube type kitchen radio. Might find one at a flea market, maybe. Doesn't have to work, although that would be a nice bonus.
ALL the components are discrete, individual units attached with wires and are, for the most part, generally readily identifiable. As is what they are attached to. Tracing out a circuit can be VERY edifying.
Or if it's broke, as a sacrificial hand's on training tool that would be great fun to fix.
Just a thought. That's how I learned a ton about all this when I was a kid.
**broken link removed** maybe to you, to me, I have learnt they come in different colurs/sizes/watts & they have a really annoying decimal point **broken link removed** & even today,**broken link removed**are different for four band & five bands, i.e. four band gold means 5%/five band gold means x1 as well as black
I find that confusing, maybe someday I will simply see a resistor resists current **broken link removed**
A capacitor is, literally, simply two metallic plates separated by an insulator. But their uses are myriad.
There is no direct connection between the two plates. In its most basic form, a capacitor will not pass DC. But it will pass AC. That's because electrons can pile up on one plate, causing a "potential" difference between the two plates that electrically mimics AC. Thus they are useful for transferring, without a DC component of a signal, the AC that needs to pass on down a circuit's path. And they're capable of storing electricity, not unlike a battery
A transistor is, basically, a diode with a control element. They have a variable behavior with their ability to restrict large current flows with much smaller current flows. This makes them, amongst many other things, very good at Amplifying signals.
Overall you did good, grasshopper. If it makes you feel any better, to this day I keep a resistor color code chart real handy. I also have a come and go problem with mistaking green for blue (vice-versa).
An ohmmeter is my friend...
BTW, don't trust checking a resistor's value in a circuit: it is most likely that it is in parallel with another component (that has resistance as well) and you will not get an accurate reading. Only test the resistor all by its lonesome.
I think I'm getting there slowly **broken link removed** I put link to banding chart I'm using in last post
Cool, So I can desolder some more bits **broken link removed** that should confirm my banding without having to buy extra parts, tell you what, this little pcb was born to die, but it's worth it's weight in gold for what I'm learning from it **broken link removed**
**broken link removed** I can't work out if your trying to get me to copy a radio design or if your saying you did **broken link removed****broken link removed**
Sorry, couldn't resist **broken link removed**
ok, feel like that kinda wasted this morning but needed saying, back to it tomorrow **broken link removed**
Edit: no need to go buy a radio, I already have one to play with that needs fixing, I just thought I'd start with something easy before delving into radio **broken link removed** but I'd be more than grateful if you stay around to help me with it once I have basics in place **broken link removed**
You're controlling the current. You are using a small current (say, the output of a microphone) to control a larger current (the amplifier circuit) to drive a speaker. With no output from the speaker you're restricting the microphone current to zero. Anything coming out off the speaker is increasing the current (generated by the microphone) in the amplifier circuit.
I can't work out if your trying to get me to copy a radio design or if your saying you did
Both. As you said, I have no intention of profiting from reverse engineering, other than learning something about the circuit. And I believe that is your intention as well.
I am guilt free. BTW, as you've probably guessed, being able to read a schematic is a very handy tool.
this little pcb was born to die said:
AMEN, bro. You're getting the hang of this process.
I'll be around. I'm enjoying this immensely. It's not often I get to show off to this degree and not annoy my wife...
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lol