Abstract: A circuit board assembly which includes an electrically insulating layer, a conductive printed wiring layer formed on the surface of the electrically insulating layer and includes a plurality of conductive paths, a conductive trace on the electrically insulating layer and apparatus for dissipating a transient in addition to a surface mount resistor fixed in relation to the trace. In some forms of the invention the surface mount resistor has opposed generally planar lips. The trace may also be generally planar. In some cases the lower lips and the trace are generally parallel. The generally planar lips of the surface mount resistor may be closer to the trace than the thickness of the surface mount resistor. A single geometric plane may extend through substantially all of the lips and all of the trace. In some cases the lower surface of the lips and the lower surface of the trace are substantially coplanar.

Abstract: A system and method for communicating between a base and a remote device in a security system. The base receives an audio signal from a telephone network via a panel and then frequency modulates the audio signal at a carrier frequency to generate an FM signal. The remote device receives the FM signal from the base, determines a phase error signal representing the phase error between the received FM signal and an output signal of a voltage controlled oscillator, determines a difference between the carrier frequency and a center frequency of the voltage controlled oscillator, and, if there is a difference, then changes the center frequency of the voltage controlled oscillator to match the carrier frequency of the FM signal.

Abstract: A half-wave rectifier including an input port for receiving an incoming AC signal, an output port for outputting a half-wave rectified signal, an operational amplifier including inverting and non-inverting input terminals and an output terminal, the inverting input terminal connected to a ground reference and a non-inverting input terminal coupled to a negative feedback loop and a first resistor. The negative feedback loop including a second resistor coupled between a first node and a second node, the first node coupling the output terminal and the output port and the second node coupling the non-inverting input terminal and the second resistor. A capacitor is coupled to the input port and in series with the first resistor.

Abstract: The present invention is a method of operating a speaker by converting an audio signal to a pulse-width modulated signal that has a plurality of positive pulses and a plurality of negative pulses as a function of the audio signal, then driving an H-bridge circuit interconnected to a speaker, wherein the H-bridge circuit comprises an A-side and a B-side, wherein the A-side comprises a first switching transistor and a second switching transistor, and wherein the B-side comprises a first switching transistor and a second switching transistor. For each positive pulse, the A-side of the H-bridge circuit is driven by pushing the first switching transistor of the A-side while grounding the second switching transistor of the A-side. For each negative pulse, the B-side of the H-bridge circuit is driven by pushing the first switching transistor of the B-side while grounding the second switching transistor of the B-side.

Abstract: A system and method for recovering a high frequency component of a slew rate controlled signal propagating along a transmission line enables the high frequency component to be recovered after being lost because of slew rate control and transmission line low pass filtering effects. The system includes a wave shaping circuit for receiving and shaping the slew rate controlled signal to recover the high frequency component. The method includes receiving the slew rate controlled signal, and recovering the high frequency component by shaping the slew rate controlled signal to produce a shaped signal, where the shaped signal includes the received slew rate controlled signal and the high frequency component.

Abstract: The invention includes a circuit to monitor batteries arranged in a parallel battery configuration for charge/discharge battery circuit operation. The circuit selectively tests for each battery's presence in a battery holder or receptacle without interrupting circuit discharging operation, e.g., physical removal, and communicates a fault condition if the battery is determined to be missing. The inventive circuit enables existing or legacy control circuitry operating with the circuit to detect individual missing batteries where the legacy control circuitry is constructed to detect only missing circuit charge paths states.

Abstract: A half-wave rectifier including an input port for receiving an incoming AC signal, an output port for outputting a half-wave rectified signal, an operational amplifier including inverting and non-inverting input terminals and an output terminal, the inverting input terminal connected to a ground reference and a non-inverting input terminal coupled to a negative feedback loop and a first resistor. The negative feedback loop including a second resistor coupled between a first node and a second node, the first node coupling the output terminal and the output port and the second node coupling the non-inverting input terminal and the second resistor. A capacitor is coupled to the input port and in series with the first resistor.

Abstract: Line load compensation and reflection reduction in a signal transmitting circuit is provided using feedback capacitors. The feedback capacitor serially coupled with a resistance generates an RC rise/fall time that is independent of the line load. Additionally, by selecting a capacitor that yields a rise/fall time of approximately ? of the maximum bit transmission time, signal reflection on the signal line can be reduced. Accordingly, by incorporating the feedback capacitor with a differential drive circuit, such as the IB 485 driver, variations in line load can be compensated for while also reducing signal reflection due to un-terminated or improperly terminated signal lines, thus allowing a free topology implementation.

Abstract: A system and method for communicating between a base and a remote device in a security system. The base receives an audio signal from a telephone network via a panel and then frequency modulates the audio signal at a carrier frequency to generate an FM signal. The remote device receives the FM signal from the base, determines a phase error signal representing the phase error between the received FM signal and an output signal of a voltage controlled oscillator, determines a difference between the carrier frequency and a center frequency of the voltage controlled oscillator, and, if there is a difference, then changes the center frequency of the voltage controlled oscillator to match the carrier frequency of the FM signal.

Abstract: The present invention is a method of operating a speaker by converting an audio signal to a pulse-width modulated signal that has a plurality of positive pulses and a plurality of negative pulses as a function of the audio signal, then driving an H-bridge circuit interconnected to a speaker, wherein the H-bridge circuit comprises an A-side and a B-side, wherein the A-side comprises a first switching transistor and a second switching transistor, and wherein the B-side comprises a first switching transistor and a second switching transistor. For each positive pulse, the A-side of the H-bridge circuit is driven by pushing the first switching transistor of the A-side while grounding the second switching transistor of the A-side. For each negative pulse, the B-side of the H-bridge circuit is driven by pushing the first switching transistor of the B-side while grounding the second switching transistor of the B-side.

Abstract: A security device including a control panel for transmitting a pre-defined cadence pattern to a siren device. The siren device takes the pre-defined cadence pattern as an input and outputs an audible voice message that corresponds to the pre-defined cadence pattern. The siren device is capable of recognizing the pre-defined cadence pattern that indicates a security system armed or disarmed command from a user interface device as well as a detected alarm signal of fire, burglary and carbon monoxide from a corresponding smoke, motion and carbon monoxide detector. These signals are transmitted from either the sensors or user interface means to the control panel and then, in turn, to the siren device.

Abstract: The invention includes a circuit to monitor batteries arranged in a parallel battery configuration for charge/discharge battery circuit operation. The circuit selectively tests for each battery's presence in a battery holder or receptacle without interrupting circuit discharging operation, e.g., physical removal, and communicates a fault condition if the battery is determined to be missing. The inventive circuit enables existing or legacy control circuitry operating with the circuit to detect individual missing batteries where the legacy control circuitry is constructed to detect only missing circuit charge paths states.

Abstract: A security device including a control panel for transmitting a pre-defined cadence pattern to a siren device. The siren device takes the pre-defined cadence pattern as an input and outputs an audible voice message that corresponds to the pre-defined cadence pattern. The siren device is capable of recognizing the pre-defined cadence pattern that indicates a security system armed or disarmed command from a user interface device as well as a detected alarm signal of fire, burglary and carbon monoxide from a corresponding smoke, motion and carbon monoxide detector. These signals are transmitted from either the sensors or user interface means to the control panel and then, in turn, to the siren device.

Abstract: A system and method for recovering a high frequency component of a slew rate controlled signal propagating along a transmission line enables the high frequency component to be recovered after being lost because of slew rate control and transmission line low pass filtering effects. The system includes a wave shaping circuit for receiving and shaping the slew rate controlled signal to recover the high frequency component. The method includes receiving the slew rate controlled signal, and recovering the high frequency component by shaping the slew rate controlled signal to produce a shaped signal, where the shaped signal includes the received slew rate controlled signal and the high frequency component.

Abstract: Line load compensation and reflection reduction in a signal transmitting circuit is provided using feedback capacitors. The feedback capacitor serially coupled with a resistance generates an RC rise/fall time that is independent of the line load. Additionally, by selecting a capacitor that yields a rise/fall time of approximately ? of the maximum bit transmission time, signal reflection on the signal line can be reduced. Accordingly, by incorporating the feedback capacitor with a differential drive circuit, such as the IB 485 driver, variations in line load can be compensated for while also reducing signal reflection due to un-terminated or improperly terminated signal lines, thus allowing a free topology implementation.

Abstract: A system for recharging and testing a rechargeable battery having first and second terminals which includes a microprocessor having at least a first port; a charger coupled to the first port and a connector for attachment to one of the terminals of the associated battery; and a comparator coupled to the charger and to the first port. The comparator compares a voltage at the first terminal of the associated battery and a reference voltage and produces respective first and second outputs. The first output is produced when the voltage at the first terminal is below a first predetermined value and the second output is produced when the voltage at the first terminal is above a second predetermined value. The charger charges the battery in response to the first output and not charging the battery in response to the second output.

Abstract: Image data from a video surveillance camera is moved from a volatile memory such as a circular buffer to a non-volatile memory such as a flash memory when a loss of signal from the camera is detected. The loss of signal may occur when an intruder disables the system such as by cutting a cable, by vandalizing the camera so that it no longer can transmit image data, or removing the camera altogether. The loss of signal is detected by determining whether a signal portion such as a start of active video code, end of active video code, or horizontal or vertical blanking interval, is present on a communication path of the camera. The system ensures that an image of the intruder is captured and stored before the system is disabled. Analog signals from the camera may be digitized for storage.

Abstract: A circuit board assembly which includes an electrically insulating layer, a conductive printed wiring layer formed on the surface of the electrically insulating layer and includes a plurality of conductive paths, a conductive trace on the electrically insulating layer and apparatus for dissipating a transient in addition to a surface mount resistor fixed in relation to the trace. In some forms of the invention the surface mount resistor has opposed generally planar lips. The trace may also be generally planar. In some cases the lower lips and the trace are generally parallel. The generally planar lips of the surface mount resistor may be closer to the trace than the thickness of the surface mount resistor. A single geometric plane may extend through substantially all of the lips and all of the trace. In some cases the lower surface of the lips and the lower surface of the trace are substantially coplanar.

Abstract: A microprocessor controlled integrated alarm and touch tone telephone system which allows the alarm system to be accessed, programmed, and reported upon through a touch tone telephone, either locally or remotely. Under most circumstances, the telephones on the premises can be operated in a normal manner. However, the alarm system selectively monitors the telephone activities for coded touch tone instructions specifically for the alarm system, and responds thereto by issuing synthesized voice reports on the status of the alarm system. A touch tone decoder circuit decodes dialed touch tones, such that the telephone can be utilized similar to a normal keyboard panel to access and control the alarm system. An internal power supply is provided for the telephone for supplying electrical power thereto independently of the outside telephone lines which normally supply power, in the event the outside telephone lines are inoperative.

Abstract: An alarm system incorporating a dynamic range testing feature whereby the system polls and tests, on a regular basis, the resistance of the circuits of alarm condition resistor elements in the alarm system, primarily to detect when the circuit of a resistor element has degraded to a pre-trouble resistance range, such that the circuit of the resistor element can be serviced and repaired prior to its degrading to a point which will trigger the alarm system. The alarm system includes a central control system, and a plurality of modules at potential alarm locations coupled by a pair of connecting lines to the central control system. Each module includes two alarm condition resistor elements associated therewith for detecting an alarm condition, which is indicated by an increase in the electrical resistance thereof, as by the opening of a switch or the breakage of a resistor element, and each module further includes a reference resistor which is provided for a reference measurement.