Plug the light bulbs and heat
gun
into
the outlets on the box. Meters on the face of the box
show
voltage and current. Connections in the back allow
voltage and
current to be displayed on an oscilloscope.
Use the switch to include or
exclude
the circuit breaker from the rest
of the circuit. The wire segment on top of the box can
be
replaced with a fine wire
that melts when >15 A is drawn, to demonstrate the purpose
of the circuit breaker. The 20 A heat gun will trip the
breaker
or melt the wire.
Plug a variac into the GFI-protected outlet, connected across
a 6 V
bulb. Trip the GFI by making contact between the ground
and
neutral wires. Do so with caution, as this is not an
isolation
amplifier.
This illustrates:
wiring of three-prong
outlets
how circuit breakers keep
wires from
burning up
how loading circuit dims
lights
ground fault interrupters
power factor in AC circuits
NOTES
actual voltage = 100 x
measured voltage
(in 100:1 voltage divider)
current = 10 x measured voltage
(across 0.1 ohm resistor)
Use the four-channel
scope, braid the leads, and display the current as the
difference
between Ch 3 and 4.
