• US Patent 335,786 3/30/1885 Electric-Arc Lamp

    • An arc lamp made with electro magnets.

  • US Patent 334,823 5/6/1885 Commutator For Dynamo-Electric Machines

    • An improvement in the commutator of DC motors.

  • US Patent 336,961 5/18/1885 Regulator For Dynamo-Electric Machines

    • A current regulator for DC motors.

  • US Patent 336,962 6/1/1885 Regulator For Dynamo-Electric Machines

    • Another current regulator for DC motors.

  • US Patent 335,787 7/13/1885 Electric-Arc Lamp

    • An improvement in the electromagnetic arc lamp that feeds carbon rods for a longer burn.

  • US Patent 350,954 1/14/1886 Regulator For Dynamo-Electric Machines

    • Mechanical means for effecting the current regulators.

  • US Patent 359,748 1/14/1886 Dynamo-Electric Machine

    • A DC motor with iron discs on the shaft.  This was the infamous motor Tesla built for Edison and expected to receive $50,000 bonus for.  Edison blew him off and said he was just joking.

  • British Patent 1,877 2/9/1886 Improvements in Electric Lamps

    • Tesla's improvement in the carbon arc lamp.

  • British Patent 2,975 3/2/1886 Improvements in Dynamo Electric Machines

    • Current regulators that improve the efficiency of DC motors.

  • US Patent 382,845 4/30/1887 Commutator For Dynamo-Electric Machines

    • An improved form of commutator for DC motors.  Half of patent granted to Charles Peck.

  • US Patent 428,057 5/26/1887 Pyromagneto-Electric Generator

    • An electric generator that uses oscillations in heat to create an oscillation in a magnetic field, which in turn causes oscillating electric current.  Patented by the Tesla Electric Company.

  • US Patent 382,280 10/12/1887 Electrical Transmission Of Power

    • Details on how to wire two and three phase motors.  

  • US Patent 381,968 10/19/1887 Electro-Magnetic Motor

    • The first AC motor.  Half of patent granted to Charles Peck.

  • US Patent 381,969 11/30/1887 Electro-Magnetic Motor

    • AC motor where stator is a large electromagnet and rotor is wound.  Half of patent granted to Charles Peck.

  • US Patent 382,279 11/30/1887 Electro-Magnetic Motor

    • AC motor with the rotor wound and closed within itself.  The stator is also wound and induces current to the rotor.  Half of patent granted to Charles Peck.

  • US Patent 382,281 11/30/1887 Electrical Transmission Of Power

    • AC motor very similar to patent #381,969.

  • US Patent 381,970 12/23/1887 System Of Electrical Distribution

    • AC power transformer using a closed iron surface such as a toroid.  Half of patent granted to Charles Peck.

  • US Patent 382,282 12/23/1887 Method Of Converting And Distributing Electric Currents

    • More detail on how to construct patent #381,970.

  • US Patent 396,121 3/30/1888 Thermo-Magnetic Motor

    • A motor that uses heat to reduce a magnetic field that results in mechanical action due to springs.

  • US Patent 390,413 4/10/1888 System Of Electrical Distribution

    • How to connect motors and loads in series.  Patented by Tesla Electric Company.

  • US Patent 390,414 4/23/1888 Dynamo-Electric Machine

    • Motors that run on either AC or DC current as well as multiphase configurations.  Patented by the Tesla Electric Company.

  • US Patent 390,820 4/24/1888 Regulator For Alternate-Current Motors

    • The variac transformer used for regulating AC current.  Patented by the Tesla Electric Company.

  • US Patent 390,721 4/26/1888 Dynamo-Electric Machine

    • Winding a motor to operate at relatively slower speeds.  Patented by the Tesla Electric Company.

  • US Patent 390,415 5/15/1888 Dynamo-Electric Machine Or Motor

    • More efficient method of manufacturing motors of either DC or AC type.  Patented by the Tesla Electric Company.

  • US Patent 487,796 5/15/1888 System Of Electrical Transmission Of Power

    • Motors and generators with differing numbers of poles, and armature and stator wound 90 degrees out of phase.  Patented by the Tesla Electric Company.

  • US Patent 511,915 5/15/1888 Electrical Transmission Of Power

    • Using induced currents to run two independent circuits in a motor.  Patented by the Tesla Electric Company.

  • US Patent 555,190 5/15/1888 Alternating Motor

    • Another induction motor.  Patented by the Tesla Electric Company.

  • US Patent 524,426 10/20/1888 Electromagnetic Motor

    • A motor where the phase difference is caused by different sized cores.  Patented by the Tesla Electric Company.

  • US Patent 511,559 12/8/1888 Electrical Transmission Of Power

    • A method for running patent 487,796 motor with one current using an inductor.  Patented by the Tesla Electric Company.

  • US Patent 511,560 12/8/1888 System Of Electrical Power Transmission

    • A method for running patent 487,796 motor with one current without using an inductor.  Patented by the Tesla Electric Company.

  • US Patent 405,858 1/8/1889 Electro-Magnetic Motor

    • A motor based on angular displacement.  Patented by the Tesla Electric Company.

  • US Patent 401,520 2/18/1889 Method Of Operating Electro-Magnetic Motors

    • Motors that start with out of phase currents until there is sufficient speed to run synchronous with the AC power supply.

  • US Patent 405,859 3/14/1889 Method Of Electrical Power Transmission

    • Method of bringing a motor up to speed by grounding and causing a double circuit between motor and generator.

  • US Patent 406,968 3/23/1889 Dynamo-Electric Machine

    • An electrical generator that works with discs passing through a magnetic field.  Two thirds of patent given to Charles Peck and Alfred Brown.

  • US Patent 459,772 4/6/1889 Electro-Magnetic Motor

    • Two motors on one shaft, one for torque, the other for synchronous operation.  Patented by the Tesla Electric Company.

  • US Patent 416,191 5/20/1889 Electro-Magnetic Motor

    • A single phase motor. Patented by the Tesla Electric Company.

  • US Patent 416,192 5/20/1889 Method Of Operating Electro-Magnetic Motors

    • A single phase motor that starts by short-circuiting the armature circuit until synchronous speed is achieved. Patented by the Tesla Electric Company.

  • US Patent 416,193 5/20/1889 Electro-Magnetic Motor

    • A motor that uses circuits of different wire diameter and thus different resistances to bring the motor to synchronous speed.  Patented by the Tesla Electric Company.

  • US Patent 416,194 5/20/1889 Electric Motor

    • A patent claiming that the most efficient motors are those with equal amounts of copper in both the armature and stator.  Patented by the Tesla Electric Company.

  • US Patent 416,195 5/20/1889 Electro-Magnetic Motor

    • A motor using multiple electromagnets arranged for maximum magnetic field action.  Patented by the Tesla Electric Company.

  • US Patent 418,248 5/20/1889 Electro-Magnetic Motor

    • A motor utilizing both direct and alternating currents.  Patented by the Tesla Electric Company.

  • US Patent 424,036 5/20/1889 Electro-Magnetic Motor

    • The shaded pole motor utilizing magnetic lag.  Patented by the Tesla Electric Company.

  • US Patent 445,207 5/20/1889 Electro-Magnetic Motor

    • A motor that uses resistance to change the lag between phases.  Patented by the Tesla Electric Company. ro3

  • US Patent 413,353 6/12/1889 Method Of Obtaining Direct From Alternating Currents

    • Tesla's invention for rectifying AC current to DC.  May have some clues to free energy devices.  It's unclear what he means by self-exciting near the end of the text.  Two thirds of patent given to Charles Peck and Alfred Brown.

  • US Patent 417,794 6/28/1889 Armature For Electric Machines

    • A more efficient armature design for motors.  Patented by the Tesla Electric Company.

  • US Patent 433,700 3/26/1890 Alternating-Current Electro-Magnetic Motor

    • A motor with improved alternating magnetic phases.  Patented by the Tesla Electric Company.

  • US Patent 433,701 3/26/1890 Alternating-Current Motor

    • A motor with shunted cores for the purpose of increasing self induction.  Patented by the Tesla Electric Company.

  • US Patent 433,702 3/26/1890 Electrical Transformer Or Induction Device

    • Transformer for producing a secondary current a given number of degrees out of phase with the primary. Patented by the Tesla Electric Company.

  • US Patent 433,703 4/4/1890 Electro-Magnetic Motor

    • Tesla shows how the thickness of the core can be altered maximize the efficiency of a motor.  Patented by the Tesla Electric Company.

  • US Patent 447,920 10/1/1890 Method Of Operating Arc-Lamps

    • Tesla uses what amounts to a rotary spark gap with hundreds of poles for increasing the rate of arc lamp pulses.  This makes the lamps run quieter.  This device could also be called a high frequency generator.  An arc lamp is essentially the same thing as a spark gap in a Tesla coil.

  • US Patent 447,921 11/15/1890 Alternating Electric Current Generator

    • A high frequency generator capable of 15kc or more. 

  • US Patent 455,067 1/27/1891 Electro-Magnetic Motor

    • A motor with an internal capacitor.

  • US Patent 462,418 2/4/1891 Method Of And Apparatus For Electrical Conversion And Distribution

    • A system for using capacitors to further increase a high tension generator output.  Tesla talks of using this system for running lights and motors.  Motors at MHz electrical frequency?  Worth studying.

  • US Patent 455,068 3/27/1891 Electrical Meter

    • Electrolytic cell electric meter.  A conductor passes through an electrolyte and as current passes through the conductor the resistance of the solution changes in direct proportion.

  • US Patent 454,622 4/25/1891 System Of Electric Lighting

    • Single wire evacuated light bulbs operating at 15kc and up.

  • US Patent 455,069 5/14/1891 1891 Electric Incandescent Lamp

    • Two terminal high frequency carbon lamps. 

  • US Patent 464,666 7/13/1891 Electro-Magnetic Motor

    • A motor with a primary and secondary that resembles a Tesla coil.

  • US Patent 464,667 8/1/1891 Electrical Condenser

    • The oil filled capacitor.

  • US Patent 514,167 1/2/1892 Electrical Conductor

    • Tesla invented a very interesting form of coax cable for preventing losses while conducting high frequencies.

  • US Patent 514,170 1/2/1892 Incandescent Electric Light

    • High frequency carbon button lamp with a shield around the conductor.

  • US Patent 514,972 1/2/1892 Electric Railway System

    • Tesla was the inventor of the trolley car system in San Francisco.  This is the patent.

  • US Patent 512,340 (PDF) 7/7/1893 Coil For Electro-Magnets

    • Bifilar (two parallel wires) wound coils. 

  • US Patent 514,168 8/2/1893 Means For Generating Electric Currents

    • Oil spark gap and method of circulating oil in a system.

  • US Patent 511,916 8/19/1893 Electric Generator

    • Tesla's mechanically oscillating electrical generator.  See also patent 514,169.

  • US Patent 514,169 8/19/1893 Reciprocating Engine

    • Same design as patent 511,916 but specified for mechanical work.  More detail given.

  • British Patent 2,801 8/19/1893 improvements in Reciprocating Engines and Means for Regulating the Period of the same

    • Tesla's compressed air mechanical oscillator.

  • British Patent 2,812 8/19/1893 Improvements in Methods of and Apparatus for the Generation of Electric Currents of Defined Period

    • Generating electricity with a mechanical oscillator.

  • US Patent 514,973 12/15/1893 Electrical Meter

    • A meter that works by measuring the amount of particles thrown off of a conductor.

  • US Patent 517,900 12/29/1893 Steam Engine

    • Another mechanical oscillator

  • US Patent 568,176 4/22/1896 Apparatus For Producing Electric Currents Of High Frequency And Potential

    • DC powered Tesla coil

  • US Patent 567,818 6/17/1896 Electrical Condenser

    • The electrolytic capacitor. 

  • US Patent 568,177 6/17/1896 Apparatus For Producing Ozone

    • DC motor used as a spark gap in a Tesla coil.

  • US Patent 568,178 6/20/1896 Method Of Regulating Apparatus For Producing Electric Currents Of High Frequency

    • Another DC powered Tesla coil with emphasis on tuning.

  • US Patent 568,179 7/6/1896 Method Of And Apparatus For Producing Currents Of High Frequency

    • The AC rotary gap Tesla coil.

  • US Patent 568,180 7/9/1896 Apparatus For Producing Electrical Currents Of High Frequency

    • Tesla uses the tips of a four bladed fan to make his rotary spark gaps at 90 degrees apart.  This allows for adjusting the gap by moving the shaft further or closer.  The fan cools the gap as it blows through a tube.  This is a further development of the Tesla coil.

  • US Patent 577,670 9/3/1896 Apparatus For Producing Electric Currents Of High Frequency

    • Alternating capacitor Tesla coil designed to keep the oscillations going without a break.  While one capacitor is discharging, the other is charging.

  • US Patent 583,953 10/19/1896 Apparatus For Producing Currents Of High Frequency

    • A DC powered, high frequency Tesla coil ingeniously designed.

  • US Patent 577,671 11/5/1896 Manufacture Of Electrical Condensors, Coils And Similar Devices

    • Application of substances that replace all air improves all manner of electrical devices.

  • US Patent 609,250 2/17/1897 Electrical Igniter For Gas Engines

    • The automobile ignition system.

  • US Patent 593,138 3/20/1897 Electrical Transformer

    • Tesla specifies three Tesla coil shapes for best results.  They are flat spiral, cone, and bipolar.  Tesla refers to his coils as transformers.

  • US Patent 609,251 6/3/1897 Electric Circuit Controller

    • Another fluid spark gap utilizing a rotating drum to separate fluids of different conductivity.

  • US Patent 645,576 9/2/1897 System Of Transmission Of Electrical Energy

    • This is a very significant patent of Tesla's concerning the generation of high voltages and for changing the state of the atmosphere such that it would conduct large amounts of power.  Although air is normally an insulator, by generating several millions of volts the state of the atmosphere is changed such that it resembles the action of higher rarefied levels of atmosphere.  This becomes the conductor that Tesla uses for transmitting power long distances and with little or no losses.  Tesla specifies the flat spiral coil as the apparatus for generating these high voltages.  One will note that in most of Tesla's poses with his apparatus, he has a flat spiral coil present.  Rarely, except in the Colorado Springs Notes, do we see Tesla working with solenoid shaped coils.  The purpose of using the flat spiral coils is they transmit higher voltages greater distances and thus allow for great demonstrations of high frequency lighting and other high frequency effects.  It is also worth noting that in the flat spiral system Tesla describes, the voltage is not stepped up just by the standard transformation ratio, but that this system generates considerably higher voltages due to the arrangement of the capacitance and inductance in the flat spiral coil.  Using these properties of a flat spiral coil, Tesla fully expected to generate 20 to 50 million volts, and possibly more, in his worldwide power transmission system.  It is through these greater forces that Tesla intended to transmit large amounts of power.

  • US Patent 649,621 9/2/1897 Apparatus For Transmission Of Electrical Energy

    • In combination with patent 645,576.  This patent describes the physical construction of the flat spiral coil oscillator.

  • US Patent 611,719 12/10/1897 Electrical Circuit Controller

    • A spark gap consisting of a fluid and compressed inert air.

  • US Patent 609,245 12/2/1897Electrical Circuit Controller

    • A spark gap utilizing a fluid stream or jet to make and break contact.

  • US Patent 609,246  2/28/1898 Electric Circuit Controller

    • A spark gap utilizing a rotating disc and a fluid stream.

  • US Patent 609,247 3/12/1898 Electric Circuit Controller

    • Another fluid spark gap.

  • US Patent 609,248 3/12/1898 Electric Circuit Controller

    • Another method of breaking a gap utilizing a fluid and moving insulator.

  • US Patent 609,249 3/12/1898 Electric Circuit Controller

    • Yet another method of breaking a gap using a fluid.

  • US Patent 613,735 4/19/1898 Electric Circuit Controller

    • A spark gap with a solid gap rotating opposite the direction of a rotating fluid.

  • US Patent 613,809 7/1/1898 Method Of And Apparatus For Controlling Mechanism Of Moving Vessels Or Vehicles

    • Tesla's radio controlled, battery powered boat. This is the patent that establishes Nikola Tesla as the first to transmit an intelligent radio signal and thus makes him the inventor of radio.

  • US Patent 685,953 6/24/1899 Method Of Intensifying And Utilizing Effects Transmitted Through Natural Media

    • This patent was filed just as Tesla was beginning his Colorado Springs experiments.  A mechanical switch discharges a capacitor at a given frequency and the current is used for operating devices.  The capacitors are charge by pulses sent from a remote transmitter at the same frequency as the mechanical switch..  The key here is that Tesla is working with pulses, not radiation or oscillations.

  • US Patent 685,955 6/24/1899 Apparatus For Utilizing Effects Transmitted From A Distance To A Receiving Device Through Natural Media

    • This is a significant patent that may relate to Tesla's later vacuum tube powered black box that powered the Pierce Arrow automobile.  This patent aims to store impulses received until a potential is built up high enough that it can be mechanically released and utilized for work.  A vacuum tube oscillator circuit could fulfill this same function.  Naturally triode and pentode vacuum tubes were not yet available while Tesla worked at Colorado Springs and so he was trying to achieve similar results with a mechanical device.

  • US Patent 685,954 8/1/1899 Method Of Utilizing Effects Transmitted Through Natural Media

    • Another patent filed while Tesla was in Colorado Springs.  This is a battery powered amplifier circuit used to amplify signals sent from his transmitter.

  • US Patent 685,956 8/1/1899 Apparatus For Utilizing Effects Transmitted Through Natural Media

    • This is another battery powered receiver amplifier circuit.

  • US Patent 655,838 1/15/1900 Method Of Insulating Electric Conductors

    • Tesla patented the method of using ice and other frozen substances as insulators and dielectrics.  It is worth noting that Tesla was in Colorado Springs when this patent was filed.  It is likely he made his discovery in the cold climate of Colorado during the winter when his salt water capacitors froze or his conductors were coated with ice.

  • US Patent 685,012 3/21/1900 Means For Increasing The Intensity Of Electrical Oscillations

    • Another patent filed just after returning from Colorado Springs and likely discovered in the cold climate.  This patent specifically relates to pouring liquid nitrogen or some other cold substance over the electrical components.

  • US Patent 787,412 5/16/1900 Art Of Transmitting Electrical Energy Through The Natural Mediums

    • Here Mr. Tesla explains what is later found to be Schumann's Resonance.  He also explains that his world power transmission system has little to do with Hertzian waves and utilizes standing waves.

  • US Patent 723,188 7/16/1900 Method Of Signaling

    • Utilizing a dual frequency transmitter and corresponding dual frequency receiver, Tesla is able to send signals with absolute privacy much like a combination lock. 

  • US Patent 725,605 7/16/1900 System Of Signaling

    • Tesla uses dual transmitters for breaking up a signal and sending it over different frequencies.  Similar to patent 723,188, this allows for more privacy over the air waves.

  • US Patent 11,865 8/14/1900 Method Of Insulating Electric Conductors

    • Ice is an excellent insulator for high voltage conductors.

  • US Patent 685,957 3/21/1901 Apparatus For The Utilization of Radiant Energy

    • This patent follows Tesla's experiments for receiving useful energy from transmitted impulses and his battery powered amplifiers.  This is the famous radiant energy patent.  To construct this patent and get results it is necessary to exercise extreme caution in sealing the terminal, wires and capacitor such that there are no electrostatic leakages.  Instead of using the mechanical switches tesla used, vacuum tube circuits could be used to trigger a pulse discharge from the capacitor.

  • >>>US Patent 685,958 3/21/1901 Method Of Utilizing of Radiant Energy

    • Similar to patent 686,597.  This patent uses a modified interrupter plan for discharging the capacitor.

  • US Patent 1,119,732 1/18/1902 Apparatus For Transmitting Electrical Energy

    • This is the final design of Wardencliffe.  The highlight of this patent is the toroid on a tower with the surface area maximized by producing hemispheres over the surface of the torus.  This unique design helps to produce exceedingly high potentials of electricity by preventing the leakage of charge during resonant rise.

  • US Patent 1,061,142 10/21/1909 Fluid Propulsion

    • The Tesla Turbine, a machine of several discs that propel fluid and thus act as a bladeless pump.

  • US Patent 1,061,206 10/21/1909 Turbine

    • The Tesla Turbine as a machine that is propelled by fluids.

  • US Patent 1,113,716 10/28/1913 Fountain

    • A more mundane invention for Tesla.  This is the fountain that produces large volumes of water flow that appears as waterfalls.

  • US Patent 1,209,359 5/29/1914 Speed Indicator

    • A speedometer utilizing similar principles to Tesla's turbine for directly converting torque into a speed gauge.  This works on the principle of primary and secondary forces, similar to his Tesla coils.  A primary mechanical action is transformed into a secondary mechanical action in direct proportion to the primary, thus providing the speed indicating property.

  • US Patent 1,329,559 2/21/1916 Valvular Conduit

    • A unique pipe that allows fluids to flow in one direction but oppose it flowing in the other direction, thus eliminating the need for mechanical check valves.

  • US Patent 1,266,175 5/6/1916 Lightning Protector

    • This patent specifically states that the Franklin style of lightning rod is inefficient and Tesla explains in principle and mathematics why this is so.  The patent is itself a quick lesson in electrostatics and worthy of reading.

  • US Patent 1,274,816 12/18/1916 Speed Indicator

    • This is the speedometer installed in every modern vehicle even today.  It is based on principles similar to patent 1,209,359.

  • US Patent 1,314,718 12/18/1916  Ship's Log

    • A speed indicator for a ship.

  • US Patent 1,365,547 12/18/1916 Flow Meter

    • A meter that converts fluid flow into mechanical action through the use of a Tesla turbine.

  • US Patent 1,402,025 12/18/1916 Frequency Meter

    • A device for measuring radio frequencies using principles similar to Tesla's velocity measuring devices.

  • US Patent 1,655,113 9/9/1921 Method Of Aerial Transportation

    • The VTOL aircraft propelled by propellers..

  • US Patent 1,655,114 10/4/1927 Apparatus For Aerial Transportation

    • The VTOL aircraft propelled by a Tesla turbine air pump.

  • British Patent 6,481 3/1/1888 Improvements relating to the Electrical Transmission of Power and to Apparatus therefor

  • British Patent 6,502 Improvements relating to the Generation and Distribution of Electric Currents and to Apparatus therefor

  • British Patent 6,527 Improvements relating to Electro-motors

  • British Patent 8,200 Improvements relating to the Transmission of Electrical Energy

  • British Patent 8,575 Improved Methods of and Apparatus for Generating and Utilizing Electric Energy for Lighting Purposes

  • British Patent 11,293 Improvements relating to the Utilization of Electromagnetic, Light, or other like Radiations Effects or Disturbances transmitted through the Natural Media and to Apparatus therefor

  • British Patent 11,473 Improvements in Alternating Current Electro-magnetic Motors

  • British Patent 13,563 Improvements in, and relating to, the Transmission of Electrical Energy

  • British Patent 14,550 Improvements relating to the Insulation of Electric Conductors

  • British Patent 14,579 Improvements in and relating to the Transmission of Electrical Energy

  • British Patent 16,709 Improvements relating to the Conversion of Alternating into Direct Electric Currents

  • British Patent 19,420 Improvements in Alternating Current Electro-magnetic Motors

  • British Patent 19,426 Improvements in the Construction and Mode of Operating Alternating Current Motors

  • Canadian Patent 24,033 Improvements in Dynamo Electric Machines

  • Canadian Patent 29,537 Improvements in Methods of and Apparatus for the Electrical Transmission of Power

  • Canadian Patent 30,172 Improvements in Methods of and Apparatus for Converting and Distributing Electric Currents

  • Canadian Patent 33,317 Improvements in Methods and Apparatus for Converting Alternating into Direct Currents

  • Canadian Patent 135,174 Improvements in Fluid Propulsion (Tesla Pump)

  • Canadian Patent 142,352 Improvement in the Art of Transmitting Electrical Energy Through the Natural Mediums

  • The above patents are public domain and nearly all of them came from Keelynet.  Keelynet is a very good source of Free Energy information.  There are also many other interesting articles and topics at Keelynet.