Correct way to solder Capacitor??

[Izzy]

Hi before I solder my caps I just wanted to make sure.

How do we solder electrolytic Polarized cap? I mean how do find out where to attch positive end and where to atatch negetive end?
Is it we use multimeter and see where the voltage is dropping and solder them according to it?


And what about film caps? If they are not labeled +/- does that mean they are non polarized caps? so the orientation doesnot matter?

[KerryF]

There should be a stripe on one side of the Polarized Capacitor.  Thats the negative.  Also, the short lead is negative and the long lead is positive.

Some caps such as film caps and ceramic caps arent polarized so you can put it in any way.

[Semperfidoe]

Are you modding or building?

If the circuit uses a polarised cap it will have some marker on the PCB to show the positive or negative side. This will be aligned with the same marker on the cap. (for example in replacing some electroytic caps they had a negative side marked and the PCB had a negative side marked. The Tantalum caps I used to mod with had the positive side marked so it simply meant turning them the right way and sticking the postive side in the unmarked hole.) If the cap has no marker then it doesnt need aligning in my limited experience.

[petemoore]

How do we solder electrolytic Polarized cap? I mean how do find out where to attch positive end and where to atatch negetive end?
  Usually it's marked on the schematic.
  If not look for a GND> if the Gnd. is negative the negative pole of the cap goes there, if it's a Pos. Gnd. Effect the positive pole goes there.
  The positive pole of an electrolytic always goes toward the most positive connection, this can be measured with the DMM.
  In cases where the cap will be exposed to + and - voltage, 'NP' or 'BP' [non-polar = Bipolar] electrolytics can be used.
 

[Izzy]

Thanks a lot.

Its liek there are 2 caps that are shown marked in schematic which are taltanum caps. But other caps are not marked in schematic. I have bought electrolytics caps for most of caps needed for this scchematic which have  bigger than 1uf valaue.

BUT i have heard electrolytic caps should always be in a right orientation right?

So it was like

Electrolytics caps = Marked
In schematis = Not marked.

haha
so I was confused about the orientation.

So am I supposed to use multimeter to find out which way those  " ? " labeled caps in the figure should be placed?

[Seljer]

going from left to right:

-that first one wont be polarized
-There it lists using a non-polarizrf electrolytic, though you could also use any other regular capacitor (but at 1uF most of them get pretty big). I think you can get away with using a regular electrolytic, just build the circuit without it and use your multimeter to figure out which if the terminals has lower potential.
-again, I don't think its polarized
-not polarized
-yep, you got the tantalum cap right, be careful with those as they're tiny and its hard to see the polarity on it
-and the other thantalum
-this is not really needed, you can put in a small cap (in the pF range) to help noise/interferences
-another non-polarized electrolytic, refer to the first one
-this one isn't polarized
-other way round
-yep, you got the one by the voltage divider for the power supply right

[Izzy]

Damn......... I bought all polarised electrolytic caps beside those two Non polarised caps mentioned in schematic.

Now what should I do? Its gonna be real hard making whole circuit without cap and uing multimeter at last to find polarity. Is there any other way?

[slacker]

Do you mean you've bought electrolytic caps for all the caps in that schematic? I didn't know you could get electrolytic smaller than about 0.1uF.

[Izzy]

No I mean for the ones with value more than 1uf.
For others I have film caps. and 2 caps are taltanum.

[slacker]

Sorry I don't quite understand what the problem is, it sounds like you've got the right caps.
On the schematic the caps that are shown like this --| |-- except the tantaniums are not polarised so it doesn't matter which way round you put them. The tantaniums should have the positive side marked on them and that goes where you've put the + on the schematic. The caps that are shown like this --| (-- on the schematic are the polarised electrolytics and they should have the negative side marked on the cap. The curved side on the schematic is the negative.
It doesn't matter which way round you put the 1uF/NP caps. If you've got polarised 1uF caps by mistake then it will probably work if you put the positive ends towards the opamps.