Then another newbee question on caps...

[Mbira]

Having put an electrolytic the wrong way in a guitar amp made me think...
...hmmm, will I ALWAYS have an electrolytic + facing the + voltage and the - facing the ground? Would the only exception be when using +/- voltages is say like an IC thing, and the - lead would face the - voltage?

Thanks,
Joel

 

[KingKai]

Sort Of....

A more general and always aplicable rule is that the + side of any polarized capacitor shoiuld be connected to the "more positive" node of the circuit. Also the negative side of the polarized capacitor should be connected to the "more negative" node of the circuit. In other words, observe the polarity from the perspective of the capacitor. If you were to be inside the cap, looking out the terminals, you would want the + terminal to be more positive than the - terminal. This preserves the aluminum oxides on the electrode and makes life good for the cap.

So, yes the cap + wants to go to the positive power supply terminal and the - to ground. Where the ground is "more negative" than the + terminal. For the negative supply, the cap - wants to go to the negative power supply terminal and the + wants to go to ground which is now "more positive". This may seem like a contradiction but it is not. Look at the connections with respect to the cap's terminals and it will make sense.

Plus (+) and Minus (-) are always relative terms.

Hope this helps.

Peace - Out, Irv

 

[Mbira]

Thanks Irv! :guinness:

 

[solder_city]

[quote author="Mbira"]Having put an electrolytic the wrong way in a guitar amp made me think...
...hmmm, will I ALWAYS have an electrolytic + facing the + voltage and the - facing the ground? Would the only exception be when using +/- voltages is say like an IC thing, and the - lead would face the - voltage?[/quote]

[quote author="Mbira"]I'm one of the best techs in town. I have over the last 2 years fixed-lets look at my invoices...I have fixed 231 amps over the last 2 years.[/quote]

:?

 

[Mbira]

Both true, *******.

:guinness:

Also,
did you notice that I was correct in my thinking there? I use a lot of intuition in my repairs-the stars and crystals guide me. I look at the amp and say "show me your imperfections".

PS: the number is now 238. No customer returns yet (knock on wood)

 

[Mbira]

Soldier_city:
looking back at your posts, I see that the last 9 of 11 posts have been attacks on people. I won't be led on by your trolling anymore, now that I know your ways.

 

[gyraf]

Hey guys!!!!

Please try to behave..

And remember the first and most important rule in this forum:

No Personal Attacks!

Jakob E.

 

[NewYorkDave]

Must be another one that got lost on his way to PSW... :grin:

 

[rodabod]

Forget about the bitching guys.... This is not the place.

Mbira, remember that voltage is referred to as "potential".

If you have two leads, one at +60V DC, and the other at +50V DC, then what is the potential difference between them?

10V

If you were to power something from it, then it would effectively be the same as having one lead at +10V and one at 0V.

So, what I am saying here is, you consider the potential difference between the two points (ie. the voltage) and attach the +ve lead to the point with the higher potential.

Can you see which way round you would attach a polarised cap between -60V and -50V :?:

 

[Mbira]

[quote author="rodabod"]Forget about the bitching guys.... This is not the place.
[/quote]

:thumb:

you consider the potential difference between the two points (ie. the voltage) and attach the +ve lead to the point with the higher potential.

Can you see which way round you would attach a polarised cap between -60V and -50V :?:

This is also just a 10v difference, so the + would go to -50v. Yes?

Thanks guys.
I really appreciate the teachers (willing and unwilling) on this forum.
:guinness:

 

[NewYorkDave]

Yes, although the differential (10V) really has no bearing on which way 'round you hook up the cap. It's the same whether the potential difference is one volt or one hundred volts.

 

[Mbira]

Dave, that's just what I said, I thought. There is a 10v difference and the + goes to the -50v. (I can see now that my sentence seemed to say there is a 10v diference THEREFORE the blah, blah, blah...sorry for the confusion.)

I wrote as you edited... :thumb: