# capacitor storage (will pay for useful answer)

D

#### Denis Allard

Jan 1, 1970
0
A 1-farad cap connected to a 1-volt supply will store 1 coulomb and 1
coulomb/second = 1amp and 1amp passed through 1ohm/second = 1 joule and 1
joule/second = 1watt
Question: if the input is 24volts and is pulsed at 60hz., how will this
affect the standard formula: W=1/2xQxU
or W=1/2xCxU2 where QorC is the charge in one of the plates in coulombs or
capacitance,W is the stored energy in joules and U is the voltage between
plates. Urgent need

Denys

L

#### legg

Jan 1, 1970
0
A 1-farad cap connected to a 1-volt supply will store 1 coulomb and 1
coulomb/second = 1amp and 1amp passed through 1ohm/second = 1 joule and 1
joule/second = 1watt
Question: if the input is 24volts and is pulsed at 60hz., how will this
affect the standard formula: W=1/2xQxU
or W=1/2xCxU2 where QorC is the charge in one of the plates in coulombs or
capacitance,W is the stored energy in joules and U is the voltage between
plates. Urgent need

What is needed is a coherent question. The answer might then follow.

RL

R

#### Robert Baer

Jan 1, 1970
0
Denis said:
A 1-farad cap connected to a 1-volt supply will store 1 coulomb and 1
coulomb/second = 1amp and 1amp passed through 1ohm/second = 1 joule and 1
joule/second = 1watt
Question: if the input is 24volts and is pulsed at 60hz., how will this
affect the standard formula: W=1/2xQxU
or W=1/2xCxU2 where QorC is the charge in one of the plates in coulombs or
capacitance,W is the stored energy in joules and U is the voltage between
plates. Urgent need

Denys

*NOTHING* will affect *any* formula!
A formula is like machine instructions; it tells one what operations
to perform.
It is up to the student to determine what is known and what is unknown
first, and next determine if sufficent information of the correct type
exists to make use of the instructions.
Certainly knowing how many gallons of water are in a specific bucket
will not help to determine the voltage of a given battery or the energy
stored in a given capacitor.

Furthermore, you have failed to adequately describe the "experiment"
with the 24 volt "pulses".
What is the internal impedance of the source?
What is the pulse shape? The width? The rise time? The fall time? Can
we really assume the pulse rate will be at the arbitrary 60 pulses per
second rate?
Are there non-linear components? Inductive? Other capacitive
components? Other resistive components?

R

#### Rene Tschaggelar

Jan 1, 1970
0
Denis said:
A 1-farad cap connected to a 1-volt supply will store 1 coulomb and 1
coulomb/second = 1amp and 1amp passed through 1ohm/second = 1 joule and 1
joule/second = 1watt
Question: if the input is 24volts and is pulsed at 60hz., how will this
affect the standard formula: W=1/2xQxU
or W=1/2xCxU2 where QorC is the charge in one of the plates in coulombs or
capacitance,W is the stored energy in joules and U is the voltage between
plates. Urgent need

You are wrong.
one Amp during one second onto one farad makes one volt.
But not one Watt. This since the start voltage is zero and the End
voltage is one volt. The medium voltage is just 0.5V and therefore
the energy only 0.5Watt.
If you don't believe it, do it with integrals.

Energy := integral over time ( u(t)* i(t) dt)

Rene

J

#### James Meyer

Jan 1, 1970
0
A 1-farad cap connected to a 1-volt supply will store 1 coulomb and 1
coulomb/second = 1amp and 1amp passed through 1ohm/second = 1 joule and 1
joule/second = 1watt
Question: if the input is 24volts and is pulsed at 60hz., how will this
affect the standard formula: W=1/2xQxU
or W=1/2xCxU2 where QorC is the charge in one of the plates in coulombs or
capacitance,W is the stored energy in joules and U is the voltage between
plates. Urgent need

Denys

How much will you pay for the answer?

How will you make the payment?

Who will determine the usefulness of the answer?

Which drug did you take before you asked this question?

Jim

T

#### Tom Bruhns

Jan 1, 1970
0
Denis Allard said:
A 1-farad cap connected to a 1-volt supply will store 1 coulomb and 1
coulomb/second = 1amp and 1amp passed through 1ohm/second = 1 joule and 1
joule/second = 1watt
Question: if the input is 24volts and is pulsed at 60hz., how will this
affect the standard formula: W=1/2xQxU
or W=1/2xCxU2 where QorC is the charge in one of the plates in coulombs or
capacitance,W is the stored energy in joules and U is the voltage between
plates. Urgent need

In addition to what else has been posted, it is not true that one
farad charged to one volt holds one joule of energy. (Perhaps you
didn't exactly say that in the first paragraph, but many might
interpret it that way...) Remember, as the capacitor discharges, the
voltage drops, and the energy is thus 1/2 joule.

One thing to realize about energy coming into and going out of a
capacitor is that if you are not very careful, much of the energy will
be dissipated as heat. If you connect a 1 farad capacitor, charged to
1 volt, to an identical capacitance with no charge, charge must be
conserved, so 1 coulomb is shared by the two capacitors: each is
charged to half a volt, and the energy stored is 2 capacitors times
1/8 joule per capacitor (half a volt, half a coulomb). You've lost
that i=C*dv/dt (or more accurately, i=C*dv/dt+v*dC/dt). That, coupled
with some basic formulas about charge and energy, should cover the
ground you need.

Cheers,
Tom

P

#### Paul Burridge

Jan 1, 1970
0
Which drug did you take before you asked this question?

LSD by the look of it.

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