MOD 4 LECTURE
AC AND DC
In this lecture you will learn about:
DC - direct current
|DC is direct current, the electrons actually
move through material. However, ELECTRONS MOVE LIKE MOLASSES IN JANUARY.
However, when you get into your car and
turn on the headlights, they come on "instantly". What happens when you
hit the switch is that you connect the circuit and the ELECTRICAL FIELD
is established. There are electrons all along the wire.
D.C. AND THE EMS! CLICK HERE
The ELECTRICAL FIELD moves at the speed
of light. Once the FIELD is on, the electrons at the other end begin to
flow. It is like the conduit from the top of Hoover Dam is always full
of water, just the gate needs to be opened for water to flow immediately.
DC is not just for batteries, all electronic
devices use DC, like your computer, TV, stereo, etc. There is a converter
inside that converts AC to DC.
POWER ADAPTER FOR COMPUTER
AC - alternating current
|A.C. CLICK HERE
- AC is alternating current.
– that is, instead of electrons flowing
in one direction down the wire like in DC, the electrons just move back
and forth with NO NET FORWARD MOVEMENT DOWN THE WIRE.
– well.. that is nice, but how doesnt explain
how current is going to flow
– in the case of alternating current, the
movement of the electrons carries the ENERGY OF THE ELECTRICAL FIELD which
moves down the wire at the speed of light
– alternating current is created in a wire
by rapidly changing the direction of a magnetic field
-- items that use alternating current draw
A LOT of amperage
|A CONVERTER FROM DC to AC (heating)
AC CURRENT ITEMS
Compare ac and dc in terms of what the
electrons are doing and what the waves look like.
What is ac? what actually uses ac
What is dc? what kind of devices
use dc current?
How is electrical current and magnetism
Why when you turn on your d.c. lights
in the car do they come on instantly instead of slowly since electrons
move so slowly?
How fast does an electrical field move?
How is alternating current created?