By Mary Bellis
The first video home security system was patented (patent #3,482,037) on December 2, 1969 to Marie Brown. The system used television surveillance.
Combination smoke and heat detector alarm
Patent Abstract - Sidney Jacoby - 3,938,115 - February 10, 1976
A combination smoke and heat detector alarm including a self contained stored energy source in the form of a cylinder of compressed gas. A T-fitting connects to the cylinder and feeds separate conduit systems leading to individual sounding devices. A fusible element is interposed in one of the conduit systems to automatically permit transfer of the compressed gas to a first sounding device upon the presence of elevated temperatures. A solenoid operated switch is interposed in the other conduit system to normally prevent the flow of gas. The solenoid is responsive to a smoke detector and is wired to open the solenoid valve upon sensing the presence of a predetermined concentration of smoke.