Newbie Caps question

[realizewhoitis]

Im looking at a parts list for a Dr Boogey and see 4 different types of caps on here: film box, ceramic, chicklet,electro-pol.  I am familiar with the cermaic ones but what are special about the other forms since their values are the same that i can get in ceramic and is there another name that the film box ones might be called.  I am trying to find them on smallbear but ill buy them all elsewhere if recomended

[Minion]

Not knowing the curcuit I would say that some Values are useing at high frequencies (ceramics) and some at low frequencies (Film ) .... ceramics are pretty good at high frequncies thought a bit brittle to me , were Film caps are better at low frequencies ....Electro caps are generally used in PSU filtering and were it is impossible to get the same Value in Ceramic or film , not desireable in the signal path but sometimes impossible to avoid ....


Cheers


PS: Wima makes a large Variety of film Box caps are are readilly available .....

[Philippe]

what are special about the other forms since their values are the same  

It could also be factors based on the size & space limitations of your particular circuit configuration (i.e. using radial vs axis) or tonal options (e.g. using a silver mica instead of  a ceramic etc.).

[petemoore]

  Never exceed the rated voltage.
  Never reverse polarity [on a polarized capacitor].
  Use the farad values you need.
  Use a capacitor material that fits these criterion, such as film caps the 'pro's' use, up to the values where they are no longer available or too bulky...using electrolytics to fit these larger values.
  GEO has a capacitor page, scope pics comparing distortions of what seem to be a nearly infinitacimal level.
   http://en.wikipedia.org/wiki/Capacitor#Dielectric_materials
  Capacitor materials:
  multilayer ceramic,  tubular ceramic...not familiar
  ceramic disc  distortion is high to the point I thought maybe I heard it once... 
  multilayer polyester film, polystyrene...oh these are nice !
  metalized polyester film...what for ?
  aluminum electrolytic...fine, unless I can find a poly that value, sometimes they have troubles processing the HF's, in which case a little .01uf or so helping [parallel] cover those frequencies may be of use.
  Build something with a socket for an input capacitor, [or offboard...just add one cap, scut/splice at the input wire [compute the series value of both the original and spliced in caps..
  Try telling the difference between a .01uf and a .015uf, or even a .01uf and .022 uf at the input position, then decide if you want to buy tighter Uf tolerances to fit your needs, such as a precision filter or something that calls for it.

[zombiwoof]

Im looking at a parts list for a Dr Boogey and see 4 different types of caps on here: film box, ceramic, chicklet,electro-pol.  I am familiar with the cermaic ones but what are special about the other forms since their values are the same that i can get in ceramic and is there another name that the film box ones might be called.  I am trying to find them on smallbear but ill buy them all elsewhere if recomended

To address the ones you listed:

...film box just means a box-shaped poly film cap, shape of the package is squared off.
..."chicklet" is a nickname for the green poly caps that are found everywhere, again a film cap in a different shape, like Chicklets gum.
...ceramic you know about
...electro-pol I assume means a polarized electrolytic cap, can be radial (both leds come out one side of the cap) or axial (tubular, leads come out opposite ends of package).  Polarized electrolytics have a + and - orientation, and usually have to be inserted one way only.

Hope this helps,
Al