UC Santa Cruz SLAC Family Day SCIPP UC Santa Cruz UC Santa Cruz Tesla SLAC Family Day University of California (SC & SD) n Prof. Hartmut Sadrozinski n Drs. Lan Zhang & David Williams n Alan Yang & Ashok Sadrozinski (Sophs) Colorado State University n Dr. Abner Soffer SLAC n Dr. Eduardo do Couto e Silva Independence H.S. San Jose n Mr. Stuart Briber

UC Santa Cruz SLAC Family Day SCIPP UC Santa Cruz Voltage starts at 120 ends up at 1 million! Transformer 14,000 volt Outlet 120 volt Resonance circuit 1 million volt Ask us about details! How does the Tesla Coil work?

UC Santa Cruz SLAC Family Day SCIPP UC Santa Cruz Learn about Transformers Where have you seen this before? Power comes out at Volts Power goes in at 120 Volts Commercial Transformer, hooked up the “wrong way” Commercial Transformer, hooked up the “wrong way”

UC Santa Cruz SLAC Family Day SCIPP UC Santa Cruz We hear a lot about conserving Power (turn off lamps, air conditioners, close refrigerator doors...) Electrical Power is just converted wind, water, thermal power It is brought to your neighborhood on high voltage lines We hear a lot about conserving Power (turn off lamps, air conditioners, close refrigerator doors...) Electrical Power is just converted wind, water, thermal power It is brought to your neighborhood on high voltage lines Transforming Power Power goes in at Volts Power comes out At 120 Volts and a transformer brings it down to 120V

UC Santa Cruz SLAC Family Day SCIPP UC Santa Cruz Transformation of Power GLAST SLAC n Power is used everywhere –At the Stanford Linear Accelerator Center (SLAC): Electricity -> New particles Quarks Power is tranformed in Space Power is tranformed in Space Black holes explode : Black holes explode : – Material -> Light, x-rays, “jets” – SCIPP&SLAC work on GLAST Mission: discover the most powerful “power plants” in the universe discover the most powerful “power plants” in the universe

UC Santa Cruz SLAC Family Day SCIPP UC Santa Cruz n Normally you can't see, hear or smell electricity, but the Tesla Coil makes Bright sparks Bright sparks Loud crackling noise Loud crackling noise The air smell strange (Ozone) The air smell strange (Ozone) SAFETY FIRST! BRACE YOURSELF! 1 Million Volts! DANGER n Distance at least 20 ft. n Computers, Gameboys, CD players, telephones to the back of the room – unplugged, switched off! n Hearing aids off, pacemakers out of room!

UC Santa Cruz SLAC Family Day SCIPP UC Santa Cruz ZorroZorro Drawing lightning with a sword

UC Santa Cruz SLAC Family Day SCIPP UC Santa Cruz Sparks to grounded sword What is happening with Zorro? Wire to safe ground What about those lights without cords? Electricity Moves Through the Air (you knew that, because you use a radio and TV)

UC Santa Cruz SLAC Family Day SCIPP UC Santa Cruz n Why does Thomas (“Mr. Electricity”) Edison look so grim? n Is it because he preferred DC current?

UC Santa Cruz SLAC Family Day SCIPP UC Santa Cruz n Why does Mr. Nicola (“Sparky”) Tesla look so dapper? n Is it because he preferred AC current?

UC Santa Cruz SLAC Family Day SCIPP UC Santa Cruz n Tesla’s Power Plant at Niagara

UC Santa Cruz SLAC Family Day SCIPP UC Santa Cruz n Nicola Tesla as a Daredevil? n Long Time Exposure makes it safe!

UC Santa Cruz SLAC Family Day SCIPP UC Santa Cruz n Tesla Revival n 271 web sites are dedicated to Nicola Tesla n Join the “Tesla Coil Web Ring”

UC Santa Cruz 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! 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 In the Tesla “swing”, the kick is supplied by the AC electrical current moving back and forth

UC Santa Cruz SLAC Family Day SCIPP UC Santa Cruz Lightning Jacob’s Ladder Corona Tesla Sparks are all related. 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! Electricity in Air

UC Santa Cruz SLAC Family Day SCIPP UC Santa Cruz How lightning works – – – – – – – – – – –– – – – –– – – – – – – – – – – – – – – – – –– – – – – – – Ground is safe!

UC Santa Cruz 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? –– – – – – – –– – – – – Safest place during a lightning storm is in a plane or car because it is a Faraday Cage 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!

UC Santa Cruz SLAC Family Day SCIPP UC Santa Cruz Chicken Wire = Mostly Holes

UC Santa Cruz SLAC Family Day SCIPP UC Santa Cruz Meet the Fighting Knight Fighting Lightning Bolt to the Head Sparks from the Feet Who is afraid of Lightning?

UC Santa Cruz SLAC Family Day SCIPP UC Santa Cruz Electrical current flows on the OUTSIDE of a metal! Is the Mystery Knight OK?Let’s check! The armored suit is safe! n It's a Faraday Cage – no electric field allowed inside. Is the Mystery Knight OK?Let’s check! The armored suit is safe! n It's a Faraday Cage – no electric field allowed inside. Invisible current Visible sparks Ground 1 Million Volts Visible sparks

UC Santa Cruz SLAC Family Day SCIPP UC Santa Cruz Fysiks is Phun! Questions? Ask after the show, , visit… You find our coordinates on the web

UC Santa Cruz 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. at UC Santa Cruz. Thanks to our hosts: n All you young scientists n Ms. Teresa Troxel and her gang n Knight Steve Williams

UC Santa Cruz SLAC Family Day SCIPP UC Santa Cruz High voltage sparks I: Jacob’s ladder R off: RJRJ R J >>R -> V J >>V R I=0 on: RJRJ R R J <<R I=V/(R J +R) R 14kV E=V J /d

UC Santa Cruz SLAC Family Day SCIPP UC Santa Cruz primary transformer secondary transformer 110 VAC -> >=14kV C gets charged high V across S S C T P2S2 S breaks down C discharges through P2 resonant circuit (S,C,P2) virtual capacitor (T -> ground) resonant circuit (S2,T) energy transfer voltage gain : power transfer/sparks at  1 ( MHz) High voltage sparks II: Tesla coil

UC Santa Cruz SLAC Family Day SCIPP UC Santa Cruz primary transformer secondary transformer S C T P2S2

UC Santa Cruz 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 SLAC Family Day SCIPP UC Santa Cruz ResonanceResonance That’s how a swing works: Match Resonance Frequency and In-Phase 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 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