(Bács, October 27th, 1854 – Merano, March 3rd, 1938)
He began his studies in engineering on the Engineering Department of the Budapest Royal József Technical University and obtained a degree in hydraulic engineering at the Technical University of Vienna in 1877. When Károly Zipernowsky was looking for someone to work in the Electric Department of the Ganz-Factory he thought of Miksa Déri.
The first result of their co-operation was the self-excitation alternating current generator, which was patented in Germany as well, and its production started in 1883. This type could also be used as a motor.
From 1883, Déri's responsibility was the representation of the Electric Department of the Ganz Factory in Austria, too. He kept in contact with Zipernowsky, first of all, in the development of a high voltage alternating current energy distribution system using transformers connected in parallel. Ottó Titusz Bláthy was also involved in this work and they exhibited their invention at the Budapest National Exhibition in 1885, after which it was applied in a series of foreign power stations. Déri did not only play an active role in experiments, but in the construction of power stations applying the new system as well.
In 1888, he - with Zipernowsky - invented a single rotor converter for one and two-phase alternating current. In 1889, Déri joined the Internationale Elektrizitats-Gesellschaft (IEG) and as a director he organised and equipped the branch of the Company in Vienna.
He developed an elevator motor which started as a single-phase repulsion motor; and in 1903 and 1904, developed the single-phase repulsion motor with a dual brush system, which is known as the Déri motor. The Austrian Union E.G. and the German Helios A.G. produced the first motor model; the Swiss BBC obtained the production licence of the Déri motor. He developed the compensated, direct current motor, also named after him, which was used for high performance reversible rolling mill drives at numerous places.
Memberships: honorary member of the Hungarian Electrotechnical Association, and of the Elektrotechnischer Verein in Vienna and associate member of the Electrotechnischer Verein in Berlin.