Below are the types of demonstrations/presentations and related discussions I can provide.

Every class or situation is different and not all of the devices and concepts may be presented at every gathering depending on time constraints, allowance for multiple sessions, cognitive ability, education level and technical interest of the group.

BASIC INTERACTIONS:

• Quick review of magnetic behavior, polarity convention, the magnet field outside of the magnet is where it all happens
• Compasses responding to an electric current in a conductor
• The “Left” hand rules (yes, left hand we are talking about electrons after all!)
• Significant size magnets reacting to a large electric current in a single conductor
• A conductor (wire) reacting with a strong magnetic field with the reaction force dependent on the direction of flow.
• Lorentz force apparatus (the e/m device with the Helmholtz coils) showing the circular deflection of a beam of electrons in a magnetic field.
• Non-ferrous (copper) conductors reacting with each other when energized with no magnetic materials involved
• Students will see parallel wires with currents flowing in the same direction are attracted to each other while those carrying currents in opposite directions repel each other
• The movement of charges: the source of all magnetism; even in permanent magnets
• Compounding and magnifying the magnetic field from electric currents using multiple turns (Solenoids) and ferrous metal cores (soft steel).
• A glimpse of a potential motor

PRACTICAL APPLICATIONS (primarily DC):

• Relays, DC motors, Speakers-linear oscillating motors
• Examples of various DC motors; cut away of an electric drill motor.
• Generating electricity using a magnetic field (they will see a small motor spin due to the motion of a magnet relative to a coil of wire)
• Generating electricity with a hand crank DC generator
• Experiencing the work required to generate electricity with varying loads
• A rare earth magnet dropped down a copper tube and take 8 – 9 sec to fall 3ft.
• A pendulum with a copper blade swinging through a strong magnetic field loses all of its energy in one swing
• Why is there always a force that opposes the direction of motion when there is an electrical current as in the case of the magnet falling down the copper pipe, the pendulum or the generator when producing a current?
• The interchangeability of a DC Motor and a DC generator and the fact that the same device is conceptually both and both processes are always going on at the same time.
• Allowing the generator to spin under the power of a battery noting the magnitude and direction of the current:
  • Spinning free with its own friction
  • Under an artificial load
  • Driving the generator fast enough to reverse the current and charge the Battery
• Relate to hybrids and regenerative braking

INTRODUCTION TO ALTERNATING CURRENT

• The elements of a transformer; broken down in pieces: primary coil, secondary coil &core; and reassembled (very short time to break down and reassemble)
• The need for changing electrical flow in order to transfer energy from primary coil to secondary coil
• The conversion of pulsating AC to Pulsating DC using diodes
• Every day examples of transformers on the home front: power supplies, low voltage control circuits for home appliances heating and cooling systems etc., soldering gun, clamp on ammeter.
• Generating Alternating current using an AC generator (car alternator with pulleys and hand crank) and experiencing the same loading effect as with DC generator.
• Observing the multiple sine waves generated by the alternator on the oscilloscope (a car alternator is a three phase alternator)
• Take the low 6 to 10 volt output of the generator and use a transformer to boost the voltage to 80 to 110 volts to light three 120 Volt CFLs
• Remove the CFLs and connect the 100v output of the first transformer to a high voltage transformer; demonstrate a 7kv to 9kv Jacob’s ladder.
• Demonstrate the production of a 8kv to 10kv spark starting with a 3volt battery (2 batteries).
• Practical demonstration the limits of transmitting 40watts a certain distance at 6volts VS 100volts
• Discuss the significance of 11Kv, 22kv, 66kv, 100Kv+, 200kv, 500kvAC , 1000kv DC on regional power transmission specifically the NW California intertie
• The reason AC is so prevalent
• The transformation of the transformer into a device for creating physical motion (loops of wire and aluminum rings will shoot up into the air)
• Introduction of the induction motor linear and rotational. They will see the field coils and the rotor (without a commutator or other direct source of electricity) which I will quickly reassembled (15sec) and run as an induction motor.