Complex sentence: This circuit was widely used in radio receivers, called regenerative receivers, between 1920 and World War 2, and such receiver circuits are still used in low-cost electronic equipment such as garage door openers.
Split into simpler sentences: This circuit was widely used in radio receivers, called regenerative receivers, between 1920 and World War 2. Regenerative receiver circuits are still used in low-cost electronic equipment such as garage door openers.