12DC Sockets

[cowboybob]

Hi Paul
So why aren't I understanding the difference if 470 is right in sum
What I'm really saying is I can see the 47k will make short less but then sum is wrong.
Only asking so I understand the theory, hopefully learning how not to make mistakes in future?????

This is the 45th edit of this post. I apologize.

Graham, let's see if the sims below help. Open them left to right, A. then B.

Note that the current levels, although different between A. and B., are the same within A. and B., throughout the circuit.

Note that the voltages across the resistors, in all examples, add up 13.9 VDC


A. View attachment 60504 View attachment 60505

B. View attachment 60506 View attachment 60507

Do these help?

 

[Muttley600]

Will have to get back to that in morning, I work as a park warden within local community & one of the groups folded last week, we have all been out for meal tonight to stay in touch as they are lovely genuine people but me & 4 beers don't go together as I dont normally drink.lol

Hope your well, was telling group about my new friend in America teaching me


Best Regards
Graham

 

[cowboybob]

Graham,

Look back at my post just before your post of last night.

I'm not sure what was there when you logged in, but I edited the booDaddy out of it and I think its much easier to understand.

 

[Muttley600]

ok, think I'm ready to make a fool of myself again **broken link removed**

so if we know the voltage of the componant we are using + the reading should always equal the V potential, no matter how many componants are fitted

**broken link removed**

Then here

there are different rules which are confusing me

From second link, but not on first

where: V = voltage in volts (V)
I = current in amps (A)
R = resistance in ohms () or: V = voltage in volts (V)
I = current in milliamps (mA)
R = resistance in kilohms (k)

For most electronic circuits the amp is too large and the ohm is too small, so we often measure current in milliamps (mA) and resistance in kilohms (k). 1 mA = 0.001 A and 1 k = 1000 .

The Ohm's Law equations work if you use V, A and , or if you use V, mA and k. You must not mix these sets of units in the equations so you may need to convert between mA and A or k and .
So where I had my original reading of 470 ohms, the actual resistor I brought was 470 ohms which would be 0.470 of a Kohm instead I should of related it to 4.7 Kohm
So I ended up with 29. mA short instead of 2.9 mA

Edited your post 45 times......EEK! **broken link removed** Thanks for trying to make it easier to understand

So when I get calculations in future, they need to be done in Kohms & not ohms

or have I totally missed it again **broken link removed** why do I get a gut feeling I'm not there yet, why don't other pages tell you to work it in Kohms **broken link removed**

Doh**broken link removed**
If you are calculating A you use ohms
If you are calculationg mA you use Kohms

Just noticed.........sorry, can I go & hide now **broken link removed**

So does that mean I'm there now for this box, just looking at prices of resistors, they are 26p each at local store or £1.90 for 100 online
whats that in $ for you, hold on $0.40 at local store for one or $2.98 for 100

So if I need to order some, is there any other parts I can order to play with?

 

[cowboybob]

So when I get calculations in future, they need to be done in Kohms & not ohms
]

Regardless of the multiplier notation(s) used (K, k, M, m,u,G,n, etc, etc,etc), I find it easiest to convert them all (by multiplying the numerical value by the notational multiplier) to the decimal equivalent before plugging them into the formula(s). Then, for your own convenience, you can convert them back with a multiplier symbol that suits you.

That is to say:

4.7k Ohms ( or 4k7) = 4700 Ohms, or 4.7M ohms is 4,700,000 Ohms, or 4.7 m Ohms = 0.0047 Ohms (the symbol for Ohms is Pi, but this font group doesn't have it, that I know of).

2.45mA = 0.00245A, or 2.45kA = 2,450 A

60mV = .060V volts, or 60kV = 60,000 volts

1.2 mW = .0012, or 1.2kW = 1200 W

By using the decimal value(s), the math necessary for solving the the equation(s) (E=IR, or E times I = watts) are mucho easier, especially if using a calculator.

Hope this helps.

 

[Muttley600]

So now I can begin theory on rear box

first question has to be, is it possible to make a PCB for 10A or as I would like a 10A load capacity is it better to make it 15A knowing full it has spare capacity so will never burn out?

Shall I put together a list of what I'll think I need then you tell me what I'm missing, the only problem there is my understanding of componants or lack of

I'm fine with sockets & leds now & incoming power through relay

what componants are involved for:

Protect from short circuit
Protect from overheating/current
Have a stable regulated 12V supply
Using same sockets, make some of them switchable between 5V & 12V

maybe build 5v reg?

 

[cowboybob]

Graham,

first question has to be, is it possible to make a PCB for 10A or as I would like a 10A load capacity is it better to make it 15A knowing full it has spare capacity so will never burn out?

I don't know the output capacity of the bike's battery or the alternator. That, of course, is an issue. 15A represents at least a 180W load.

Shall I put together a list of what I'll think I need then you tell me what I'm missing, the only problem there is my understanding of componants or lack of

Sounds good to me.

Protect from short circuit

Fusses.

Protect from overheating/current

Heat sinks.

Have a stable regulated 12V supply

Most electronics designed for 12 VDC usage have built regulation since all 12 VDC automotive system's alternators charge at greater than 12 VDC. That said, you probably don't need to worry about regulating the >12 VDC power coming from your distribution box.

Using same sockets, make some of them switchable between 5V & 12V

If you use a 1k ohm limiting resistor for the LED circuit, it will work for both voltage levels. 4.7K won't.

maybe build 5v reg?

A different one from the one you showed in your initial design?

From a previous post:

So if I need to order some, is there any other parts I can order to play with?

some parts stores sell assorted packs of components, i.e., a resistor pack with 100 total that include various values in lots of 5 or ten. I find them very useful and pretty cheap. They are, however, very low wattage ( 1/8 W, generally). Same with capacitors, etc.

You're having way to much fun...

CBB

 

[Muttley600]

Ok back on phone now, you have picked up the multi quote great

I can't remember all your replies but that sounds far too simple.lol
The idea is to learn lots, hence trying to make box as complicated as possible.
Yes, I'm a glutton for punIshment
I've already worked out bike theory, I'll post that tomorrow as off out for meal with Inlaws tonight, go out about 4 times a year drinking then I get 2 nights in a row. Eek!

Thanks for all your help so far Paul
Think Im going to do myself a chart showing where decimal point is in relation to different values to keep

& yes I'm in my element, having lots of fun & mistakes are good to make along the way to help remember things, not bad for someone with lots of labels
OCD, dislexic & a short term memory issue, can remember things from 20yrs ago like it was yesterday, just don't ask me what happened 20 mins ago
Challenging myself helps take my mind off things

Best Regards from your loyal friend
Graham

By the way, this is a great hobby

 

[cowboybob]

By the way, this is a great hobby

Ain't it though. Been at it since I was 8.

BTW. I, too, have several alphabet soup, how shall I say, cognitive quirks.

On that note, I joined a new organization the other day. It's call DAM.

"Mothers Against Dyslexia".

Chortle...

Thank you for your kind words, Graham.

73s,

Paul

 

[4pyros]

first question has to be, is it possible to make a PCB for 10A or as I would like a 10A load capacity is it better to make it 15A knowing full it has spare capacity so will never burn out?

Keep the high current stuff off the PCB. Just hard wire it point to point.

 

[cowboybob]

Sound advice, 4pyros.

 

[Muttley600]

Mothers Against Dyslexia".

Chortle...

Paul

Lol, have they noticed yet

 

[Muttley600]

Keep the high current stuff off the PCB. Just hard wire it point to point.

What would you class as high current stuff....... Over what amps?

Me thinking I have lots of learning to do

But I'll settle for power boxes, radio repair, programming etc, don't want to give myself unrealistic expectations :-/

 

[4pyros]

What would you class as high current stuff....... Over what amps?

Me thinking I have lots of learning to do

But I'll settle for power boxes, radio repair, programming etc, don't want to give myself unrealistic expectations :-/

The main power leads from the battery to the jacks. Use only signal lines on a board.
I would do this hole thing with point to point wiring and no board at all.

 

[Muttley600]

The main power leads from the battery to the jacks. Use only signal lines on a board.
I would do this hole thing with point to point wiring and no board at all.

Ok it's now 2.20am, can't sleep for thinking about this next project.....sigh

So I need to turn this negative energy I'm feeling into positive energy so going to rethink so it does work somehow?
I don't know how yet but there isnt a solution that cannot be found in my world it's just that I don't have the answer yet

 

[4pyros]

Get some sleep the answer will come.

 

[Muttley600]

Get some sleep the answer will come.

No time to sleep I'm back at work on Saturday.lol

Ok, just found a link on here where I can do the bit I want, learning about pcb, hopefully it will take months with lots of questions
Then a company will make boards, I'm taking it I would get to fit parts to it so I feel like its mine, so that would achieve goal of having idea, learning & seeing usable end product

That seems better, so first I go with your idea & make MK 1, then play with pcb for learnings sake
Happy again

 

[cowboybob]

That seems better, so first I go with your idea & make MK 1, then play with pcb for learnings sake
Happy again

I've gone that route, i.e., concept to PCB (at no small expense), populate the sucker with components, solder it all in, test it, make necessary repairs, add circuit additions forgotten while designing PCB, add component additions somehow missed in PCB layout, test again, reverse power it (having forgotten diode safety components), fry critical parts and traces, wait a week and plant a garden, rethink concept and life in general, find religion...

That said, go for it, dude!!

 

[4pyros]

rethink concept and life in general, find religion

Love it!

 

[Muttley600]

fry critical parts and traces, wait a week and plant a garden, rethink concept and life in general, find religion...
That said, go for it, dude!!

I can do garden & think of concepts, I don't do religion as I think there are two types of people in this world we live in, good & bad. If religion helps some of the good cope with life, great
Ive got to go for it, I can see finished article in my head.lol

Love it!

But as you said 4pyros, it makes sense to get a working design first.

Then I shall move onto learning once I know what componants I need.

Can't wait until the morning now............oh hold on it is morning, 4.45am
I will be able to get back on computer about 9 without being frowned upon
by my beloved' for making a noise all night

Is it 9 yet.lol