Nikola Tesla was an inventor who obtained around 300 patents worldwide for his inventions. Some of Tesla's patents are not accounted for, and various sources have discovered some that have lain hidden in patent archives. There are a minimum of 278 patents issued to Tesla in 26 countries that have been accounted for. Many of Tesla's patents were in the United States, Britain, and Canada, but many other patents were approved in countries around the globe.Cheney, 62 Many inventions developed by Tesla were not put into patent protection.
American
Patents #1–#50
- Commutator for Dynamo Electric Machines - 1886 January 26 - Elements to prevent sparking on dynamo-electric machines; Drum-style with brushes. - Electric Arc lamp - 1886 February 9 - Arc lamp with carbon electrodes controlled by electromagnets or solenoids and a clutch mechanism; Corrects earlier design flaws common to the industry. - Electric arc lamp - 1886 February 9 - Arc lamp's automatic fail switch when arc possesses abnormal behavior; Automatic reactivation. - Regulator for dynamo electric machines - 1886 March 2 - Two main brushes connected to helices coil ends; Intermediate point branch shunt connection for third brush. - Regulator for Dynamo Electric Machines - 1886 March 2 - Auxiliary brush[es] shunting a portion or whole of the field helices coil; Regulates energy flow; Adjustable level of current. - Regulator for Dynamo Electric Machines - 1886 October 19 - Automatic regulation of energy levels; Mechanical device to shift brushes. - Dynamo electric machine - 1887 March 22 - Improve construction; Facilitate easier construction; Reduce the cost; Magnetic frame; Armature; Alternating current synchronous motor. - Electro magnetic motor - 1888 May 1 - Mode and plan of operating electric motors by progressive shifting; Field Magnet; Armature; Electrical conversion; Economical; Transmission of energy; Simple construction; Easier construction; Rotating magnetic field principles. - Electro Magnetic Motor - 1888 May 1 - Novel form and operating mode; Coils forming independent energizing circuits; Connected to an alternating current generator; Synchronous motor. - System of Electrical Distribution - 1888 May 1 - Current from a single source of supply in the main or transmitting circuit induce by induction apparatus; Independent circuit(s); Electric distributor. - Electro Magnetic Motor - 1888 May 1 - Rotation is produced and maintained by direct attraction; Utilizes shifting poles; Induction magnetic motor. - Electrical Transmission of Power - 1888 May 1 - New method or mode of transmission; Dynamo motor conversion with two independent circuits for long distance transmission; Alternating current transmission; Includes a disclaimer; Economic; Efficient. - Electrical Transmission of Power - 1888 May 1 - Improvements in electromagnetic motors and their mode or methods of their operations; Motor is wound with coils forming independent circuits on the armature; Armature is mounted to rotate between two different poles; Armature will eventually synchronize with that of the generator; Windcoils or coils on the field magnets; Expose to continuous current to maintain a permanent field. - Method of Converting and Distributing Electric Currents - 1888 May 1 - Related to electric distribution systems; Current is from a single main source or suitable transmitting circuit; Induction into an independent circuit; Divide the current from a single source; Transformations; Discovery of method to avoid prior liable and dangerous methods; True Dynamic induction. - Commutator for dynamo electric machines - 1888 May 15 - Relates to dynamo-electric machines or motors; Improvements on devices to collect or communicate currents; Avoids destruction and wear of machine; Avoid adjustments due to destruction and wear; Enable practical construction of very large dynamo electric machines or motors with the minimum number of communicator segments; Increases safety and efficiency. - System of electrical distribution - 1888 October 2 - Related to previous electric distribution systems developed by Tesla; Examples of systems in operation with motors or converters, or both, in parallel; Examples of systems in parallel; Examples of systems in series. - Dynamo Electric Machine - 1888 October 2 - Related to the patents of Tesla and Charles F. Peck, numbers: US381968 and US382280; Ordinary forms of continuous and alternate current systems may be adapted to Tesla's system, with slight changes to the systems; Effects their forms; Only the best and most practical solutions are presented to the three most common forms of the devices applicable; Illustrated are the continuous (or closed) circuit machines, machines possessing armatures with coils connected diametrically (known as "open-circuits"), and machines with armature-coils of which have a common joint. - Dynamo Electric Machine or Motor - 1888 October 2 - Improvement in the construction of dynamo or magneto electric machines; Novel form of frame and field magnets that renders the machine more sturdy and compact as a structure; Requires fewer parts; Less difficulty in construction; Lower expense; Useful to alternating and continuous current machines. - Dynamo Electric Machine - 1888 October 9 - Relates chiefly to the alternate current machine invented by Tesla; Related to patents numbered US381968 and US382280; Seeks to avoid mechanical drawback of running high frequency machines; Efficient at low speeds; Producing rotating magnetic poles in one element of the machine and drive the other at a different speed. - Regulator for Alternate Current Motors - 1888 October 9 - Improvement in the electrical transmission systems; Means of regulating and power of the motor or motors; Used with system of multiple motors primarily (or systems with motors and transformers) that have independent energizing circuits which act to set up progressive or shifting magnetic poles (i.e. the rotating magnetic field); Controls the speed of the motor. - Thermo Magnetic Motor - 1888 January 15 - Widely known that heat applied to a magnetic body will lessen its magnetizing ability; High enough temperatures will destroy the magnetic field; Mechanical power by a reciprocating action obtained from the joint action of heat, magnetism, and a spring or weight (or other force); In this patent, the application of heat to a body that is magnetized by induction or otherwise to the action of heat until the magnetism is neutralized to allow a weight or a spring to give action and lessen the action of the heat to restore the magnetic effect to move the body in the opposite direction. - Method of Operating Electro Magnetic Motors - 1889 April 16 - Improvements to previous instances of synchronous motors; Previous instances of synchronous motors have not been started by the alternating current generators; New discovery of simple method or plan of operating such motors; Requires no other device other than the motor itself; Conversion from a double circuit motor and which will start under the actions of an alternate current into a synchronizing-motor; synchronous motor definition. - Electro Magnetic Motor - 1889 June 25 - Torque, instead of being the result in the difference in the magnetic periods or phases of the poles or to the attractive parts to whatever due, is produce to the angular displacement of the parts which, though movable with the respect to one another, are magnetized simultaneously, or approximately so, by the same currents; Concerns the armature and the field laminations of the magnetic core for the greatest magnetic attractions; Best means to achieve these results. - Method of Electrical Power Transmission - 1889 June 25 - New and useful method of bringing up the motor to a desirable speed; Forms of alternating current machines, connected to alternating current generators, can be run as synchronous motor; Prior, alternating current will not start it; Construct a generator with two coils or sets of coils and connect them with a motor of corresponding coils or sets of coils; By means of two line wires, the motor and generator in like fashion; Related to US 390413 (for means of starting); Will operate as a single-circuit synchronizing system. - Dynamo Electric Machine - 1889 July 16 - Relates to class of machines referred to as "Unipolar" machine (i.e., a disk or cylindrical conductor is mounted in between magnetic poles adapted to produce a uniform magnetic field); Construction of a machine with two fields, each having a rotary conductor mounted between its poles; Discussed the disk form primarily; The direction of the magnetism or order of the poles in one field of force is opposite to that of the other, so the rotation of the disk in the same direction forms a field from the center to the circumference and another from the circumference to the center; Contacts applied to the shafts form terminals of a circuit to produce a sum of electromotive forces of the two disks; If direction of the fields are the same, driving the disks in the opposite direction will obtain the same results. - Method of Obtaining Direct current from Alternating Currents - 1889 October 22 - Superiority of alternating currents discussed; Delineates machines to convert alternating currents to direct (or continuous) currents at will at one or more points; Obtain direct currents from alternating currents; Active resistances to opposite electrical character, whereby the currents or current-waves of opposite character will be diverted through different circuits. - Electro-Magnetic Motor - 1889 December 3 - Induction motor with two or more energizing circuits; alternating currents of differing phases are passed to produce rotation or operation of the motor; simple way consists of two circuits; alternate way consists of one line that divides the alternating current in the motor circuit and effects an artificial lag in one of the circuit of branches (such as by a different induction capacity). - Method of Operating Electro-Magnetic Motors - 1889 December 3 - Related to US401520; Alternative improvements to synchronous motors; Torque and synchronous actions in motors; different field circuit of differing induction; Windings and shunts; Increases tendency to synchronize. - Electro-Magnetic Motor - 1889 December 3 - Induction motor operation with two or more windings; securing differing phase differences; Phase proportional to the induction and inverse to the resistance encountered by the current; one circuit (the energizing circuit) should have high induction and low resistance (along with possessing the greater length or number of turns) and the converse in the other (which has few turns of finer wire or wire that has higher resistance); magnetic quantities of the poles should be approximately equal; Self-induction cores are much longer. - Electric Motor - 1889 December 3 - Drawings include the motor seen in many of Tesla's photos; Classic alternating current electro-magnetic motor; Induction motor operation; Field and armature of equal strengths or magnetic quality; field and armature cores of equal amounts; Coils containing equal amount of copper. - Electro-Magnetic Motor - 1889 December 3 - Induction motor operation with two or more windings; Differing phases; Structural and operational conditions; Armature operation conditions and the obedience to the energizing circuit and stator; Construction and organization principles. - Armature for Electric Machines - 1889 December 24 - Construction principles of the armature for electrical generators and motors; Simple and economical; Coils of insulated conducting wire (or ribbon) may be wound or formed into bobbins; Position of the bobbins dictate the windings; Armature has polar projections and maximum core-surface exposure to the field magnetic poles; Related to other applicant patents, numbers US327797, US292077, GB9013.