Re: cap question

Bill,

By the time you do all that, Jan and I will have our larger capacitor
wired and working. Even if we didn't save any money, we will have
surely saved time and complexity...

As Henry David Thoreau suggested, "Simplify, simplify..."

Ballendo

--- In CAD_CAM_EDM_DRO@y..., Bill Vance <ccq@x> wrote:
> On Mon Apr 1 21:35:05 2002, JanRwl@a..., <JanRwl@a...> wrote:
>
> >In a message dated 01-Apr-02 21:55:50 Central Standard Time,
> >pbweber@j... writes:
> >
> >
> >> I'm thinking a zener diode to ground rated a little
> >> above the rated voltage of the cap?
> >
> >
> >Paul: This first must assume the zener you'd USE for that has a
sufficient
> >WATTAGE to accept the over-voltage, and the current through it
that would
> >result therefrom. This can cause WORSE "explosions", not to
mention damage
> >to the power-supply bridge-rectifier, or VR, if used.
> >
> >One way to "protect" the zener is to insert a low-R (0.1 ohm,
etc.) of how
> >many, fifty watts?, in series with the zener. And, use a 50 W
zener. Ever
> >price those???
> >
> >This is simply one of those "good ideas on paper which are not
practical".
> >Best engineering is to design with a CAP rated for the "worst
case" voltage!
> >It doesn't have to be "close", just "over"! MUCH cheaper
alternative to
> >"engineering a fix for an imagined, not-yet-experienced
problem!!!!! Jan
> >Rowland
>
> Couldn't you use a transistor to drop it? Consider: One of the
ways zeners are
> used to regulate voltage, is to put a potentiometer between it and
ground. Now
> if at that zener/pot juncture, you connect the base of an NPN
transistor with
> the emitter going to ground, and the collector connected above the
zener, the
> transistor would drop the voltage everytime the zener reached it's
limit. An
> extra pot might be needed between the juncture and the transistor
base, in order
> to adjust the transistor properly, but you could get away with
using a
> lightweight zener that way.
>
> Bill
>
> --
> --------------------------------------------------------------------
--------
> RKBA! ***** Blessings On Thee, Oh Israel!
***** 4-19!
> ----------------+----------+--------------------------+-------------
--------
> An _EFFECTIVE_ | Insured | All matter is vibration. | Let he who
hath no
> weapon in every | by COLT; | -- Max Plank | weapon sell
his
> hand = Freedom | DIAL | In the beginning was the | garment and
buy a
> on every side! | 1911-A1. | word. -- The Bible | sword.--
Jesus Christ
> ----------------+----------+--------------------------+-------------
--------
>
> Constitutional Government is dead, LONG LIVE THE
CONSTITUTION!!!!!
>
> --------------------------------------------------------------------
--------