| 摘要 |
A fire protection system of the type having a plurality of electrically activatable, parallel coupled fire suppressant units each having a bridge wire type initiating element, produces significantly improved reliability by providing each of the units with an electrically active portion for continuously monitoring the electrical continuity of the associated bridge wire and a discrete capacitive portion for storing an independent, electrical supply of the actuating power therefor, thereby eliminating the dependency of the units on a single, central electrical power supply source while also allowing continuity monitoring of each bridge wire, even though the latter are continuously coupled in parallel relationship with each other. A control circuit associated with each of the suppressant units limits the flow of electrical current in one direction through both the corresponding bridge wire and capacitive portion to a low level in order to effect charging of the latter, but allows a high level current to flow in the opposite direction through the bridge wire upon discharge of the capacitive portion to produce activation of the associated unit. A centrally located, detecting device is operative to sense either the loss of a supervisory current which is allowed to flow through the control lines coupling the units into parallel relationship, due to an open circuit condition in such control lines, or a trouble signal produced by the active portion of one of the releasing units indicating an open circuit condition in the bridge wire associated with an inoperable unit.
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