Download Theremin Experiment

Theremin Experiment
But what IS a Theremin?
• A Theremin is a device that changes pitch by
sensing the players hands in relation to itself.
• It was created in 1920 by Leon Theremin.
• Leon’s machine uses antenna to sense hand
position, and then feed to a loud speaker
• Our build uses a photo receptor to sense light,
and therefore our hand.
This is what its supposed to look like
Components
• There are only four components to our
Theremin. They are :
• 1-100k ohm resistor
• 1-photo cell (light dependant resistor)
• 1-100 micro faraday capacitor
• 1- LM386 integrated circuit
• These components are so small…..
100k ohm resistor
• A resistor works by passing electricity through
a medium that resists the flow of energy.
http://en.wikipedia.org/wiki/Resistor
100k ohm resistor
colour
1st
band
2nd band
3rd band
4th band
(multiplier) (tolerance)
Black
0
0
X10^0
Brown
1
1
X10^1
+/- 1% (F)
100 ppm
Red
2
2
X10^2
+/- 2% (G)
50 ppm
Orange
3
3
X10^3
15 ppm
Yellow
4
4
X10^4
25 ppm
Green
5
5
X10^5
+/- 0.5% (D)
Blue
6
6
X10^6
+/- 0.25% ( C )
Violet
7
7
X10^7
+/- 0.1% (B)
Grey
8
8
X10^8
+/- 0.05% (A)
White
9
9
X10^9
Gold
X10^-1
+/- 5% (J)
Silver
X10^-2
+/- 10% (K)
none
+/- 20% (M)
Temp. Coefficient
100k ohm Resistor
• The amount of resistance is calculated as
such:
Therefore this resistor is 10x10^4 ohms +/- 50
ohms OR 100000 +/- 50 ohms.
Photo Receptor
• A photo receptor uses a semiconductor that
uses photons to start the flow of electrons,
therefore increasing resistance.
http://www.rp-photonics.com/photodetectors.html
http://en.wikipedia.org/wiki/Photodetector
1-100 Micro Farad Capacitor
• A capacitor stores energy and releases it
either as a single high voltage pulse, or as a
continuous stream, depending on the circuit's
resistance.
• A capacitor works by allowing static electricity
to accumulate, and then be released.
1-100 Micro Farad Capacitor
• A Farad is the SI unit for capacitance named
after Michael Faraday. (god of capacity)
• One farad is how much charge a capacitor
takes per every volt.
http://en.wikipedia.org/wiki/Capacitor
http://electronics.howstuffworks.com/capacitor.htm
100 Micro Farad Capacitor
Ours
LM386 Integrated Circuit Chip
http://en.wikipedia.org/wiki/LM386
• Widely used in battery powered acoustic
electronics.
• Takes between 4-18 volts, and outputs
between 325mW, and 1000mW.
LM386 Integrated Circuit Chip
• The LM386 passes current and voltage
through sets of resistors to give logic
http://www.wiringdi
functions.
agrams21.com/2009/
03/12/lm386-specsfeatures-andapplication-audiopower-amplifier
Measurements
component
Resistance (ohms)
Current (amperes)
Potential
difference (Volts)
Photo receptor
From 0.9 – 6.8
-----
0.02
Resistor
98300
-----
3.87
Capacitor
No resistance to
almost infinite
resistance
-----
4.98
Total circuit
-----
5.3
6.24
Galvanoscope
• A galvanoscope is a type of ammeter used for
detecting electrical current.
• This is not to be confused with the galvanometer,
as a galvanometer gives a definite measurement,
whereas a galvanoscope gives a rough
magnitude.
• It works by having several turns of wire around a
magnetic needle, so that when magnetic fields
move, so does the needle and attached plate.
Galvanoscope
• The magnetic coil was given more turns in the
wire to multiply the effect of a single turn on
the needle.
• The magnetic field flowing through the wires
turns the needle to identify that current is
flowing through.
• The galvanoscope is important because it
provides safety to scientists that routinely
work with electricity.
http://physics.kenyon.edu/EarlyApparatus/Ele
ctrical_Measurements/Galvanoscope/Galvano
scope.html
A Galvanoscope
http://chestofbooks.com/crafts/popular-mechanics/The-Boy-Mechanic-700-Things-for-Boys-toDo/How-To-Make-A-Galvanoscope.html
Scientific, Technological, Societal and
Environmental Implications
• The galvanoscope was first developed by Hans
Oersted in 1820. It was developed further to
have “multipliers” that helped to determine
the magnitude of a current.
• In 1858, William Thomson (Lord Kelvin)
developed what is now a galvanometer.
• The galvanoscope allowed mankind to
become more advanced in the use of
electricity.
Mass Spectrograph
Mass Spectrograph
• A mass spectrograph is a device that identifies
a substance.
• First It burns a sample, then adds a charge to
the particles. It then propels them through a
magnetic field, and calculates the mass of the
particle from where it lands on a detector
plate. (lighter particles are deflected more
than heavier ones)
Scientific, Technological, Societal and
Environmental Implications
• Mass Spectrometers allow people to measure
particulate in the air, soil, and water to check
for contamination.
• Mass Specs are used in solving crimes.
• Mass specs are also helping to evolve the
detectors of colliders such as the LHC at Cern.
http://en.wikipedia.
org/wiki/Electromag
net
Lifting Electromagnets
An electromagnet is a magnet in which the magnetic
force is produced by the flow of current flowing
through a wire wound into a coil. By winding like this,
the magnetic field created by the current is
concentrated. The magnetic field can be enhanced
further if a “core, ” such as a soft iron is placed in the
middle. By having the core, the current aligns the
domains within the core, which results in an increase
in the electrical current, increasing the magnetic field
further. The advantage of using this type of magnet is
that it can be easily manipulated by adjusting the
electrical current to allow for heavier lifting.
Lifting Electromagnets
• In 1820, Hans Orsted discovered that electric
currents create magnetic fields. Four years
later, William Sturgeon developed the first
electromagnet. His electromagnet was
horseshoe shaped and wrapped in bare
copper wire. It only weighed 200 grams and
was able to lift 4 kilograms. In 1827, Joseph
Henry improved the magnet greatly by
winding much more wire around the metal
and allowing the magnets he created to lift
http://en.wikipedia.org/wiki/Electromagnet
936 kilograms.
Electromagnets
• Electromagnets allow society nowadays to lift
many heavy objects with ease. They are used
often in junk yards to lift around the broken and
old vehicles. Electromagnets give humans to lift
metal objects that normally could not be lifted
by magnetic force. These magnets are very
important to have in our society.
http://en.wikipedia.
org/wiki/Electromag
net
http://www.youtube.co
m/watch?v=gk6PpeXgM8
Scientific, Technological, Societal and
Environmental Implications
• Lifting electromagnets have been used in
applications ranging from auto body
construction, to scrap metal destruction.