And yes, I have seen only two BRK 1769ACI smoke alarms in my lifetime. I would really like one for my collection, but they are super rare now. I believe they are ionization detectors from the early 80’s, unlike it’s brother, the System Sensor version, which looks very slightly different and is photoelectric. There is a local nursing home around here that still has many of the SS versions of these detectors, some of which have been replaced in the 90’s with the SS 2400 series.
Here is the System Sensor (12 or 24 volt, no sounder) version of the BRK 1769ACI. I believe these were the very first System Sensor detectors ever produced. System Sensor was founded in 1984 by BRK Electronics, as their “commercial fire alarm” division. BRK did produce system detectors before 1984, but they were branded as BRK, not System Sensor. So, it is possible that this is a pre-1984 BRK system detector.
