Odd, home fire and smoke detectors were invented in 1955 Jones, Hilton Ira (April 1955).
"Peeps at Things to Come".
The Rotarian (Rotary International)
86 (4).
From Wiki: "
Ionisation smoke detectors were first placed on the market in the United States in 1951 and were used only in major commercial and industrial facilities in the next several years due to their high expense and large size.
[50] In 1955, simple home "fire detectors" for homes were invented.
[51] They detected high temperatures as the fire cue.
[45] The
United States Atomic Energy Commission (USAEC) granted the first license to distribute smoke detectors using radioactive material in 1963.
[46] The first truly affordable home smoke detector was invented by
Duane D. Pearsall in 1965, featuring an individual battery powered unit that could be easily installed and replaced.
[52] These first units, dubbed "SmokeGard 700,"
[53] were made from strong fire resistant steel and shaped much like
bee hives.
[1] The company began mass producing these units in 1975.
[49] Studies in the 1960s determined that smoke detectors respond to fires much faster than heat detectors.
[45]
The first single-station smoke detector was invented in 1970 and made public the next year.
[45] It was an ionisation detector powered by a single
9-volt battery.
[45] They cost about $125 and sold at a rate of a few hundred thousand per year.
[50] Several technological developments occurred between 1971 and 1976, including the replacement of cold-cathode tubes with
solid-state circuitry, which greatly reduced the detectors' sizes and made it possible to monitor both the decrease in voltage and the build-up of internal resistance in the battery.
[50] The previous alarm horns, which required specialty batteries were replaced with horns that were more energy-efficient, enabling the use of commonly available sizes of batteries.
[50] These detectors could also function with smaller amounts of radioactive source material, and the sensing chamber and smoke detector enclosure were redesigned for more effective operation.
[50] The rechargeable batteries were also replaced with a pair of
AA batteries along with a plastic shell encasing the detector. The 10-year-lithium-battery-powered smoke alarm was invented in 1995.
[45]"
