Abstract: An automatic bypass switch comprising an electronic switch circuit responsive to voltage signals generated by the delay circuit and armed status of an electronic alarm system. The output of the bypass switch is connected to one or more detection circuits so as to shunt or prevent activation when the control has been armed until the delay circuit has been activated. From this time until the panel has been disarmed and rearmed again, the controlled detection circuit(s) is active and not shunted.

Abstract: A fire alarm control system in which an electronic switch circuit is responsive to an increase input current signal generated by one or more fire detection devices. A local alarm is connected to the electronic switch circuit to indicate an alarm state. A delay timer circuit is connected to the electronic switch circuit and operated thereby to activate a remote alarm after a predetermined time delay. A manual two-position switch is movable to a silence position from its normal position within the time delay to disable the local and remote alarms and movable back to its normal position to cut off power to the detection devices and electronic switch means to unlatch the alarms. A further pair of manually operable switches are provided to instantaneously reactivate the disabled local and remote alarms when the two-position switch is in the normal position.