Transcript TESLA_SLAC_Fam_day_AS

UC Santa Cruz Tesla @ SLAC Family Day
SCIPP
UC Santa Cruz
UC Santa Cruz Tesla Coil
@ SLAC Family Day
University of California (SC & SD)
 Prof. Hartmut Sadrozinski
 Drs. Lan Zhang & David Williams
 Alan Yang & Ashok Sadrozinski (Sophs)
Colorado State University
 Dr. Abner Soffer
SLAC
 Dr. Eduardo do Couto e Silva
Independence H.S. San Jose
 Mr. Stuart Briber
UC Santa Cruz Tesla @ SLAC Family Day
SCIPP
UC Santa Cruz
How does the Tesla Coil work?
Ask us about details!
1 million
volt
Transform
voltage
from
120 volts
to
1 million
Volts!
Resonance circuit
14,000
Transformer
volt
120
volt
Outlet
Where have
you seen
this before?
UC Santa Cruz Tesla @ SLAC Family Day
SCIPP
UC Santa Cruz
Transforming Power
Electrical Power is converted wind, water, or thermal power.
14,000 volts
120 volts
UC Santa Cruz Tesla @ SLAC Family Day
SCIPP
UC Santa Cruz
SLAC
Transformation of Power

GLAST
Power is used everywhere
– At the Stanford Linear
Accelerator Center (SLAC):
– 45 billion volt electricity ->
New particles, quarks

Power is tranformed in Space

Black holes explode :
– Material -> Light, x-rays, “jets”
– SCIPP&SLAC work on GLAST
Mission:
discover some of the universe’s
most powerful “power plants”
UC Santa Cruz Tesla @ SLAC Family Day
SCIPP
UC Santa Cruz
SAFETY FIRST!



Distance at least 20 ft.
Computers, Gameboys, CD players,
telephones to the back of the room –
unplugged, switched off!
Hearing aids off, pacemakers out of
room!

Normally you can't see, hear or smell
electricity, but the Tesla Coil makes
• Bright sparks
• Loud crackling noise
• The air smell strange (Ozone)
1 Million
Volts!
DANGER
BRACE YOURSELF!
UC Santa Cruz Tesla @ SLAC Family Day
SCIPP
UC Santa Cruz
Zorro
Drawing lightning with a sword
UC Santa Cruz Tesla @ SLAC Family Day
SCIPP
UC Santa Cruz
Sparks
Electricity
to grounded sword
Moves
What about
Through the Air
those lights
without cords?
(you knew that,
What is happening with Zorro?
because you use
Wire to safe
ground
a
radio and TV)
UC Santa Cruz Tesla @ SLAC Family Day
SCIPP
UC Santa Cruz

Why does Thomas (“Mr. Electricity”) Edison look so grim?

Is it because he preferred DC current?
UC Santa Cruz Tesla @ SLAC Family Day
SCIPP
UC Santa Cruz

Why does Mr. Nicola (“Sparky”) Tesla look so dapper?

Is it because he preferred AC current?
UC Santa Cruz Tesla @ SLAC Family Day
SCIPP
UC Santa Cruz

Tesla’s Power Plant at Niagara
UC Santa Cruz Tesla @ SLAC Family Day
SCIPP
UC Santa Cruz

Nicola Tesla as a Daredevil?

Long Time Exposure makes it safe!
UC Santa Cruz Tesla @ SLAC Family Day
SCIPP
UC Santa Cruz



Tesla Revival
271 web sites are dedicated to Nicola Tesla
Join the “Tesla Coil Web Ring”
UC Santa Cruz Tesla @ SLAC Family Day
SCIPP
UC Santa Cruz
Learn about Resonance
That’s how a swing works:
A kick at the right moment
builds up and gets you sky-high!
In the Tesla “swing”, the kick is supplied
by the AC electrical current moving back and forth
UC Santa Cruz Tesla @ SLAC Family Day
SCIPP
UC Santa Cruz
Electricity in Air
Lightning
Jacob’s Ladder
Corona
Tesla Sparks
are all related.
Principle: Air is made of very small bodies called
“molecules”. When they are broken apart (“ionized”), they
become charged and can conduct a current like an
electrical wire.
If there is a large current, it heats up the air and makes
light (like in your toaster!).
Thus, the sparks, flames etc are direct evidence for the
model of atoms!
UC Santa Cruz Tesla @ SLAC Family Day
SCIPP
UC Santa Cruz
How lightning works
+ +
+
+
+
+
+
+ +
+
+
+
+
– –
– –
–
– – –
–
–
–
–
–
–
–
– –––
– – –– ––
+ – –
+
+
+
+
+
–
+ –
+
+
–
+ –
+
+
–
+
+
– + –
+
+ –
+
+ –
+
+
–
–
–
–
+ + +
+
+
+ + +
+
Ground is safe!
+
+
+
+
+
+
–
++
+ + +
+ + + + + +
UC Santa Cruz Tesla @ SLAC Family Day
SCIPP
UC Santa Cruz
The Faraday Cage
+
Planes are close to the clouds
and away from safe ground.
Why aren’t they in grave
danger from lightning?
Answer: They form a
“Faraday Cage” -- that is,
they are surrounded by
metal.
Electricity flows around the
outside of the metal, and
anything inside is safe!
–
+ +
+
+
+ + +
+
+ +
+
+
+
–
–
– – – – – –
– – – –
+
+
+ +
+
Safest place during a lightning
storm is in a plane or car
because it is a Faraday Cage
UC Santa Cruz Tesla @ SLAC Family Day
SCIPP
UC Santa Cruz
Chicken Wire = Mostly Holes
UC Santa Cruz Tesla @ SLAC Family Day
SCIPP
UC Santa Cruz
Meet the Fighting Knight
Who is afraid of Lightning?
Fighting Lightning
Bolt to the Head
Sparks from the Feet
UC Santa Cruz Tesla @ SLAC Family Day
SCIPP
UC Santa Cruz
Is the Mystery Knight OK?
The armored suit is safe!

It's a Faraday Cage – no
electric field allowed inside.
Let’s check!
Invisible
current
1 Million Volts
Visible
sparks
Visible
sparks
Ground
Electrical
current
flows on the
OUTSIDE of
a metal!
UC Santa Cruz Tesla @ SLAC Family Day
SCIPP
UC Santa Cruz
Fysiks is Phun!
Questions?
Ask after the show, e-mail, visit…
You find our coordinates on the web
http://scipp.ucsc.edu
UC Santa Cruz Tesla @ SLAC Family Day
SCIPP
UC Santa Cruz
Say “Good bye” to
Daniel Greenhouse,
the brain behind the sparks
He was an undergraduate
at UC Santa Cruz.
Thanks to our hosts:



The SLAC Family
Ms. Nina Adelman-Stolar
The Knight
http://scipp.ucsc.edu
UC Santa Cruz Tesla @ SLAC Family Day
SCIPP
UC Santa Cruz
High voltage sparks I: Jacob’s ladder
E=VJ/d
14kV R
off:
R
on:
RJ
R
RJ>>R -> VJ>>VR
RJ<<R
I=0
I=V/(RJ+R)
RJ
UC Santa Cruz Tesla @ SLAC Family Day
SCIPP
UC Santa Cruz
High voltage sparks II: Tesla coil
• 110 VAC -> >=14kV
• C gets charged
• high V across S
T
primary
transformer
S
C
P2
S2
secondary
transformer
• S breaks down
• C discharges through P2
• resonant circuit (S,C,P2)
1  1 / P 2  C
• virtual capacitor (T -> ground)
• resonant circuit (S2,T)
 2  1 / S 2  T  1
• energy transfer
• voltage gain :
VT  C / T VC  100kV
• power transfer/sparks at 1 (10-100 MHz)
UC Santa Cruz Tesla @ SLAC Family Day
SCIPP
UC Santa Cruz
T
primary
transformer
S
C
P2
secondary
transformer
S2
UC Santa Cruz Tesla @ SLAC Family Day
SCIPP
UC Santa Cruz
Transformer 101:
Energy (Power ) (at best! - heat, sound, motion!) conserved
 I*V constant
Primary (n1) and secondary (n2) share the Magnetic Flux 
(use iron core!)
 V1  n1*d/dt
 V2  n2*d/dt  n2/n1* V1
UC Santa Cruz Tesla @ SLAC Family Day
SCIPP
UC Santa Cruz
Resonance
That’s how a swing works:
Match Resonance Frequency and In-Phase
In the Tesla “swing”, the kick is supplied
by the Primary Coil, so it has to be tuned
to the secondary circuit to be in resonance