"non-polar" capacitor?

[Ian McLaughlin]

Jim,

These are non-polarized (or bi-polar) electrolytics.  An example is the following digikey part number: 493-12697-3-ND

You can always whip one up out of your junk box - just put 2 normal (polarized) electrolytic in series with the polarities alternating (for example, connect the two positives together).  Each capacitor has to be twice the value of the result - so for example, to replace a 1uF 50v non-polarized, you can put two 2uF in series.

Hope this helps.

Ian

> On Jul 30, 2016, at 10:24 PM, Jim Brain <brain at jbrain.com> wrote:
> 
> Since I acquired a Coco Orchestra 90 unit awhile back, and I am trying to find the source of some humming in my system when the Orch 90 unit is operational, I looked at the schematic:
> 
> 
> http://www.colorcomputerarchive.com/coco/Documents/Manuals/Hardware/Orchestra-90%20CC%20Stereo%20Music%20Synthesizer%20(Tandy).pdf
> 
> 
> (page 109 of the PDF)
> 
> I understand the ROM, the resistor ladders, and the latches, but analog is not my strong suit.  I made my way through the op-amp design, but I am stumped on one component (actually three)?
> 
> 
> C7,C9, and C10
> 
> They look like electrolytic polarized caps, but are NP (non polarized), with no '+' on the schematic.
> 
> 
> Can someone shed light on what these are and where you would find them (or if they can safely be replaced with another kind of capacitor)?  I will admit I've never seen mention of these before now.
> 
> Are they "bipolar"?
> 
> http://www.digikey.com/product-detail/en/nichicon/UVP1H010MDD/UVP1H010MDD-ND/242804
> 
> 
> Or, are they called something else now?
> 
> Jim
> 
> 
> 
> 
> 
> -- 
> Jim Brain
> brain at jbrain.com
> www.jbrain.com
> 
> 
> 
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