Starter question

On Feb 1, 8:55 am, Tauno Voipio wrote:
wrote:
On Jan 31, 6:53 pm, john smith wrote:

In article .com,

wrote:

Coils (inductors) are current storage devices.
Capacitors are voltage storage devices.

As if current and voltage were independent of each other?
The coil will produce a surge of current, which has a specific
pressure that we call voltage. You can't have current flow without
voltage; any flow (amperage) requires pressure (voltage) to drive it.
Just like water in a hose.

It seems that you need some basic physics repeat training.

The quote above about storage is correct for capacitances
and inductances.

An inductance converts current changes into voltage changes
in such a way that it opposes the original current changes,
that is, an inductance smoothes current flow at the expense
of voltage changes.

A capacitance converts voltage changes into current changes
in such a way that it opposes the original voltage change,
that is, a capacitance smoothes a voltage at the expense
of current changes.

The magneto produces a pressure upward of 20,000 volts. It
does this using a pair of coils and a switch (points). Your
automobile's ignition system probably produces 40,000 volts, again
using paired coils. Both of those systems have a primary coil that
produces the current surge (which has a voltage spike) when its
current flow is interrupted, and the collapsing magnetic field
produces the huge spike in the secondary coil for use at the spark
plug.

The voltage from a magneto (or a simple spark coil) comes from
two sources:

- the abrupt break of the current in the primary winding of
the coil. It creates a voltage spike to (in vain) keep the
current smooth.

- the transformation ratio of the primary to the secondary
winding in the coil.

A magneto works in the same way as a spark coil, but the initial
current is created by a generator action of the moving magnet.


So tell me where I was wrong.

Dan

wrote:
On Feb 1, 8:55 am, Tauno Voipio wrote:

wrote:

On Jan 31, 6:53 pm, john smith wrote:

In article .com,

wrote:

Coils (inductors) are current storage devices.
Capacitors are voltage storage devices.

As if current and voltage were independent of each other?
The coil will produce a surge of current, which has a specific
pressure that we call voltage. You can't have current flow without
voltage; any flow (amperage) requires pressure (voltage) to drive it.
Just like water in a hose.

It seems that you need some basic physics repeat training.

The quote above about storage is correct for capacitances
and inductances.

An inductance converts current changes into voltage changes
in such a way that it opposes the original current changes,
that is, an inductance smoothes current flow at the expense
of voltage changes.

A capacitance converts voltage changes into current changes
in such a way that it opposes the original voltage change,
that is, a capacitance smoothes a voltage at the expense
of current changes.


The magneto produces a pressure upward of 20,000 volts. It
does this using a pair of coils and a switch (points). Your
automobile's ignition system probably produces 40,000 volts, again
using paired coils. Both of those systems have a primary coil that
produces the current surge (which has a voltage spike) when its
current flow is interrupted, and the collapsing magnetic field
produces the huge spike in the secondary coil for use at the spark
plug.

The voltage from a magneto (or a simple spark coil) comes from
two sources:

- the abrupt break of the current in the primary winding of
the coil. It creates a voltage spike to (in vain) keep the
current smooth.

- the transformation ratio of the primary to the secondary
winding in the coil.

A magneto works in the same way as a spark coil, but the initial
current is created by a generator action of the moving magnet.



So tell me where I was wrong.

Dan


He

--- quote ---

As if current and voltage were independent of each other?

-- end quote --

They are - the circuit impedance ties them together.

--- quote ---

The coil will produce a surge of current, which has a specific
pressure that we call voltage.

-- end quote --

The coil *suppresses* surges of *current* by producing surges
of voltage. Here, the coil is the impedance creating the relation
of voltage and current.

--- quote ---

You can't have current flow without
voltage; any flow (amperage) requires pressure (voltage) to drive it.
Just like water in a hose.

-- end quote --

There are weird things called superconductors, where this
does not apply - in normal conductors, the conductor resistance
is the impedance tying voltage and current together.

--

Tauno Voipio
tauno voipio (at) iki fi