Stupid schematic-reading question

[Magnus Danielson]

> 
>    I've been mostly lurking on this list for a while.  I'm fairly new to
> electronics in general, so this might be a stupid question; if it is I
> apologize in advance.
> 
>    I hope this is considered on-topic:
> 
>    I've been looking over some old Roland schematics (202/303/606/808)
> with the intention of (possibly) building my own versions of these
> instruments and using these designs as learning tools for eventually
> designing my own equipment.
> 
>    The schematics themselves are actually pretty simple, but I've got a
> bit of a problem with the capacitor values.  Some of the values are just
> numbers without values; I'm assuming these are microfarads but I'm not
> sure.  Others are expressed as a number, a slash, and then another number;
> kind of like a fraction, except I don't think the numbers make sense as
> capacitor values.  (e.g. 10/16, 1/50, 47/16, .47/50, 33/6.3)

Yes, there is a _bad_ habit among many schematic drawers to omit the uF note.
You will quite often find values being expressed in uF even if they should
be written diffrently.. 1000 uF should be 1 mF and 0.00022 should be 220 pF
and that 0.01 cap should be written 10 nF...

For electrolytic/tantal caps it is quite common that you denote their voltage
range in that way. the 47/16 is a 47 uF 16V cap, which is quite standard BTW.

Nonpolarized caps usually take higher voltages so for normal signal level stuff
you can omitt mentioning it.

>    I've checked all the electronics books I can find (admittedly, not
> many) and none of them have any information on this notation for capacitor
> values.  I'm completely stumped on this one, people.  I'll greatly
> appreciate any help you can give me.

Well, it's really a case of habbit. I think it is a bad habbit but I am sure
that someone will disagree with me...

>    Thanks in advance, everyone. :)

Hope you got a little wiser....

Magnus