Re: Please clarify European resistor value notation for me

Joerg <notthisjoergsch@xxxxxxxxxxxxxxxxxxxxx> wrote:

Mike Monett wrote:

Joerg <notthisjoergsch@xxxxxxxxxxxxxxxxxxxxx> wrote:


I don't 'get' the funny US caps with curly plates though.


On CAD I do. Can be very handy when you need to indicate where the
outside layer should be connected to. That can matter a lot in audio
gear.


Regards, Joerg


Also indicate the negative terminal on electrolytics?

That can be dangerous.

Why? If the curved plate is suitable for indicating the outside layer, it
should be good enough to indicate polarity. It is also useful to indicate
the rotor on variable capacitors. This is generally grounded to minimize
hand capacity effects when tuning, or to prevent rf burns or electrocution
in high power transmitters.

However, I did a brief search and found to my horror that the curved plate
is now rare. If it is used, the symbol also has a "+" sign on the flat
plate to indicate polarity. Which is OK, really. Redundancy in polarity
markings can't hurt.

However, I'm concerned that the symbol for variable capacitors seems to
have changed to two flat plates with a diagonal arrow. There is no way to
indicate which plate is the rotor. But I suppose that will eventually go
the way of the buggy whip, since variable caps are used so rarely these
days.

Regards,

Mike Monett

Antiviral, Antibacterial Silver Solution:
http://silversol.freewebpage.org/index.htm
SPICE Analysis of Crystal Oscillators:
http://silversol.freewebpage.org/spice/xtal/clapp.htm
Noise-Rejecting Wideband Sampler:
http://www3.sympatico.ca/add.automation/sampler/intro.htm
.