Hi Don,
Here¹s what I¹ll using for my boards this summer! I have chosen the
following types because they are reasonably easy to get straight off the peg
and are the latter day equivalents of what were originally used in the
design. (Is this sounding like a fashion show?!)
1. Use ceramic discs for low voltage supply rail/signal decoupling, i.e.
C4,C20,C22-23,C31,C36-43
2. Use plastic film or polyester types instead of the old mylars used in the
original board. The polyester ones are C9,C24. The plastic films ones almost
exclusively 0.047uF!
3. Use aluminium electrolytic types with a tolerance of 20%
I don¹t know how the other members feel and this might be a contentious
issue, but DO NOT use tantalum bead capacitors. The legs come off, they
shift value and blow up if incorrectly polarised. Nasty little things!
For more details on the types used see the Farnell parts list on Jed¹s site.
Hope this helps!
Andy
On 28/05/2010 16:56, "backshall1 (dsl)" <backshall1@bellsouth.net> wrote:
>
>
>
>
>
> Hi Andy,
>
> Any similar thoughts on capacitors? There are so many types out there, the
> cheapest being the little ceramic discs. Would it hurt to use a more
> expensive cap of different material in its place if capacitance is the same
> and voltage requirements were met, and it's non-polarized?
>
> Don B.
>
> _____
>
> From: PolySix@yahoogroups.com <mailto:PolySix%40yahoogroups.com>
> [mailto:PolySix@yahoogroups.com <mailto:PolySix%40yahoogroups.com> ] On Behalf
> Of
> Andrew Jury
> Sent: Friday, May 28, 2010 11:33 AM
> To: PolySix@yahoogroups.com <mailto:PolySix%40yahoogroups.com>
> Subject: Re: [PolySix] Re: [Group Buy PCBs]
>
> Hi,
>
> There is no problem with this. However, 5% carbon film resistors are general
> less expensive because of their lower tolerance. Try and stick to the spec
> if you can, but never use a lower tolerance component where a higher is
> specified! I.e. 5% instead of a 1%, etc
>
> Cheers,
> Andy
>
> On 28/05/2010 14:46, "del_poolp@hotmail.com <mailto:del_poolp%40hotmail.com>
> <mailto:del_poolp%40hotmail.com>
> " <del_poolp@hotmail.com <mailto:del_poolp%40hotmail.com>
> <mailto:del_poolp%40hotmail.com> > wrote:
>
>> >
>> >
>> >
>> >
>> >
>> > Hi,
>> >
>> > I have another question.
>> >
>> > You think that have a problem there if I use only resistances metal 1 %
> (on
>> > the place of 5%) ??? it's ok for recent project, but for this old system
> ????
>> >
>> > Thanks,
>> > PooLP
>> >
>> > PS : Sorry for my english
>> >
>> >
>> >
>> >
>> >
>
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>
> [Non-text portions of this message have been removed]
>
>
>
>
>
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