Heinrich Johann Welker (9 September 1912 in Ingolstadt – 25 December 1981 in Erlangen) was a German theoretical and applied physicist who invented the "transistron", a transistor made at Westinghouse independently of the first successful transistor made at Bell Laboratories.

[5] From 1951 to 1961, Welker headed of the solid-state physics department of Siemens-Schuckertwerke, in Erlangen, where he developed the new, III-V compounds such as gallium arsenide and indium antimonide, to replace silicon semiconductors.

His work resulted in large-scale use of galvanomagnetic and optoelectronic effects, as well as new switching circuits in microelectronics.

[4][6] While at the Westinghouse subsidiary in Paris, Welker and German physicist Herbert F. Mataré developed a point contact semiconductor amplifier, demonstrated in June 1948.

This coincided with the announcement by Bell laboratory scientists of the demonstration of a point contact transistor on 30 June 1948.