Fire Alarm - 1954 know how

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05:05:48

         The first issue of POPULAR ELECTRONICS, October 1954, on page 26 has article on 1CZ1 tube fire alarm.  Note 117 V.A.C. line in power fuse protection not shown -  alarm shut off is upper left line switch - no mains power means no fire alarm ( unless battery powered) - important that cathode connected to grounded side of power line and tube plate to hot line in to operate.
         Bottom horizontal line is detector line with Woods metal (50% bismuth, 12.5 tin, 12.5% cadmium, and some lead so hot water 158 degrees F. can melt it) this line is serial connection through fire protection areas possibly connected to water pipe as end ground connection.  Adjust 2.2 megohm resistor to length of fire system detection line so open in detection wire allows tube grid drop allowing tube plate to complete relay to power bell circuit.
         To simulate: open switch in bottom detection line then close vertical throw switch completing plate to cathode connection turning relay and bell transformer on.  Light represents bell.  Perhaps, a 1954 bell is loud enough to notify fire department???

published 11 years ago

Sine_eyed

11 years ago

That's neat..

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