Abstract: A safety circuit used in low-voltage connecting systems leaves the two low-voltage systems disconnected until it determines that it is safe to make a connection. When the safety circuit determines that no unsafe conditions exist and that it is safe to connect the two low-voltage systems, the safety circuit may connect the two systems by way of a “soft start” that provides a connection between the two systems over a period of time that reduces or prevents inductive voltage spikes on one or more of the low-voltage systems. When one of the low-voltage systems has a completely-discharged battery incorporated into it, a method is used for detection of proper polarity of the connections between the low-voltage systems. The polarity of the discharged battery is determined by passing one or more test currents through it and determining whether a corresponding voltage rise is observed.

Abstract: Current transformer relays having dual functions as current transformers and electromechanical switches are described. The current transformer relay includes a relay coil and a conducting loop concentric with the relay coil. Additional functions are thus provided in addition to the main relay switching function or functions. The concentric nature of the relay coil and the conducting loop create a current transformer between these elements. The additional functions include the ability to measure an alternating current (AC) current conducted by the conducting loop, the ability to detect and interpret an information signal imposed on power lines connected to the conducting loop, the ability to induce or impose an information signal on the conducting loop for transmission to power lies connected to the conducting loop, and the ability to measure a differential current between currents carried by the conducting loop and a second concentric conducting loop.

Abstract: A safety circuit used in low-voltage connecting systems leaves the two low-voltage systems disconnected until it determines that it is safe to make a connection. When the safety circuit determines that no unsafe conditions exist and that it is safe to connect the two low-voltage systems, the safety circuit may connect the two systems by way of a “soft start” that provides a connection between the two systems over a period of time that reduces or prevents inductive voltage spikes on one or more of the low-voltage systems. When one of the low-voltage systems has a completely-discharged battery incorporated into it, a method is used for detection of proper polarity of the connections between the low-voltage systems. The polarity of the discharged battery is determined by passing one or more test currents through it and determining whether a corresponding voltage rise is observed.

Abstract: Current transformer relays having dual functions as current transformers and electromechanical switches are described. The current transformer relay includes a relay coil and a conducting loop concentric with the relay coil. Additional functions are thus provided in addition to the main relay switching function or functions. The concentric nature of the relay coil and the conducting loop create a current transformer between these elements. The additional functions include the ability to measure an alternating current (AC) current conducted by the conducting loop, the ability to detect and interpret an information signal imposed on power lines connected to the conducting loop, the ability to induce or impose an information signal on the conducting loop for transmission to power lies connected to the conducting loop, and the ability to measure a differential current between currents carried by the conducting loop and a second concentric conducting loop.