Fire detection system including an automatic polarity sensing power and signal interface

A fire safety system comprising:

• a plurality of devices,
• a control panel for controlling said plurality of devices in said fire safety system, said control panel comprising a central processor unit and one or more controllers operably connected to said central processor unit for transmitting and receiving signals from said devices;
• a pair of lines are connected to said controller for transmitting signals between said control panel and said devices;
• at least one rectifier circuit operatively connected between said lines and at least one device, wherein said at least one rectifier circuit is comprised of at least a first transistor and a second transistor, each said transistor providing the circuit with a low-impedance ground path when said transistor is turned on, said transistors further providing a polarity insensitive output.

A circuit for providing a polarity sensing power and signal interface comprising:

• a first line and a second line;
• a rectifier circuit operably connected to said lines, wherein said rectifier circuit is comprised of at least a first transistor and a second transistor, each said transistor providing the circuit with a low-impedance path to ground and providing the circuit with a polarity insensitive output;
• a first capacitor operably connected to said first transistor and a second capacitor operably connected to said second transistor, wherein said first capacitor provides a delay to said first transistor when said first transistor is turned on to keep said first transistor turned on when a low voltage is applied to said rectifier circuit, and wherein said second capacitor provides a delay to said second transistor when said second transistor is turned on to keep said second transistor turned on when a low voltage is applied to said rectifier circuit, said capacitors allowing said transistors to provide a low impedance path to ground when a low voltage is applied to the circuit;
• and
• a first diode operably connected to said first transistor and a second diode operably connected to said second transistor, wherein said diodes increase the speed in which the transistors are turned on, said diodes further providing the circuit with an initial ground reference.