According to Google Ngrams, it was during the Great Depression – around the late 1930s – that the term “feedback loop” began to appear frequently in books, often in relation to electronics.
Podle Ngramu od Googlu to bylo během velké hospodářské krize – okolo konce 30. let – kdy se začal často v knihách objevovat termín “zpětnovazební smyčka”, obvykle ve vztahu k elektronice.