Abstract: Implementations of a backpack that can be converted into a protective vest are provided. In a first configuration, the backpack may be used to store and transport items. When confronted with an imminent threat (e.g., an active shooter), the backpack can be converted to a second configuration that serves as a protective vest configured to provide ballistic protection for the wearer's chest and back (i.e., body armor). The backpack does not need to be removed from the wearer's torso when being converted to the protective vest configuration. The protective vest contains at least one ballistic armor insert in both the front and rear panel sections thereof. The backpack includes a container that is detachable therefrom. This detachable container may include an internal pocket that contains at least one ballistic armor insert and enarme that allow the detachable container to be used as a shield.

Abstract: Implementations of a backpack that can be converted into a protective vest are provided. In a first configuration, the backpack may be used to store and transport items. When confronted with an imminent threat (e.g., an active shooter), the backpack can be converted to a second configuration that serves as a protective vest configured to provide ballistic protection for the wearer's chest and back (i.e., body armor). The backpack does not need to be removed from the wearer's torso when being converted to the protective vest configuration. The protective vest contains at least one ballistic armor insert in both the front and rear panel sections thereof. The backpack includes a container that is detachable therefrom. This detachable container may include an internal pocket that contains at least one ballistic armor insert and enarme that allow the detachable container to be used as a shield.

Abstract: A two-wire resistance temperature detector (RTD) includes an RTD sensor having a sensor resistance that changes in correspondence with changes in the temperature of the RTD sensor. The two-wire RTD additionally includes a pair of leads electrically coupling the RTD sensor to a control unit having a pulse generator for generating a first current pulse and a second current pulse. The two-wire RTD also includes a switch electrically coupled between the pair of leads and operable in an open state when subjected to the first current pulse and operable in a closed state when subjected to the second current pulse. The open state causes the first current pulse to flow through the pair of leads and the RTD sensor. The closed state causes the second current pulse to flow through the pair of leads. The switch enables the control unit to determine the sensor resistance and corresponding sensor temperature.

Abstract: A two-wire resistance temperature detector (RTD) includes an RTD sensor having a sensor resistance that changes in correspondence with changes in the temperature of the RTD sensor. The two-wire RTD additionally includes a pair of leads electrically coupling the RTD sensor to a control unit having a pulse generator for generating a first current pulse and a second current pulse. The two-wire RTD also includes a switch electrically coupled between the pair of leads and operable in an open state when subjected to the first current pulse and operable in a closed state when subjected to the second current pulse. The open state causes the first current pulse to flow through the pair of leads and the RTD sensor. The closed state causes the second current pulse to flow through the pair of leads. The switch enables the control unit to determine the sensor resistance and corresponding sensor temperature.