Abstract: The present invention provides a radio frequency (“RF”) activation system with improved operating capability and ease of installation. Improved responsiveness is provided by the receiver which determines the frame timing of incoming signals and calculates the estimated time of arrival for ensuing frames thus minimizing loss of frame synchronization problems. In one embodiment, this is accomplished by determining the time span of the frame start sequence and using this to determine the frame timing of an incoming RF signal. The receiver also makes corrections for timing errors between the receiver and transmitter by re-synchronizing the receiver with the incoming RF signal.

Abstract: A motorcycle helmet, snowmobile helmet, or other apparel worn by riding a vehicle is coupled with a brake light assembly. The brake light assembly includes a receiver circuit for receiving an encoded radio frequency (RF) signal from a transmitter located on the vehicle. The receiver circuit turns on the brake light for a predetermined amount of time after the brake signal is received. The transmitter is turned off for a second predetermined amount of time after the encoded signal is transmitted. The second predetermined amount of time is less than the first predetermined amount of time. The second predetermined amount of time is advantageously a pseudo random of time. The radio-controlled brake light system advantageously increases noise immunity and spurious illumination of the brake light in response to signals from other riders or operators.

Abstract: A motorcycle helmet with a brake light includes a duty cycled receiver circuit for receiving a radio frequency (RF) signal from a transmitter located on the motorcycle. The receiver circuit is generally turned off if the RF signal is not present. When the receiver detects the RF signal, the receiver is turned on. The brake light is illuminated when the receiver receives the RF signal. The brake light includes LEDs for providing light. The lens is a plastic lens which provides superior performance having spherical indentations on an interior surface.

Abstract: The invention comprises a method for operating a door hold-open device and a device for carrying out the method. A door hold-open device which unlatches a held door based upon the occurrence of an unlatch condition includes a door latching mechanism, a signal processing circuit having a power source. The method consists of the steps preventing the signal processing mechanism from consuming electrical current, upon occurrence of an unlatch condition, generating a unlatch condition signal and providing electrical current to the signal processing mechanism to power it, determining the continued existence of the unlatch condition signal with the signal processing mechanism and upon determination of the continued existence of the unlatch condition signal with the signal processing mechanism, transmitting an electrical unlatch signal to the door latching mechanism.

Abstract: A door hold open device for use with fire doors connected to a door closer unit. The hold open device has a latching means that automatically unlatches if the power supply drops below a predetermined threshold or a person attempts to disconnect the power supply. The device includes an electrical actuating means for unlatching the held open door. The actuating means allows a door to be latched open without constant current being supplied to the actuating means, so battery power is possible. The invention may be used with any door closer unit, does not require special wiring, and may include a self-contained power supply and an integral smoke detector.

Abstract: A combination charging unit and portable, hand-held transceiver which includes a latch mechanism operable to effect an electrical connection between the charging circuit in the charging unit and the rechargeable power supply in the transceiver automatically upon insertion of the transceiver into the charging unit. The latch mechanism causes insertion of plug connectors on the charging unit into mating connectors in the transceiver in a direction which is perpendicular to the axis of insertion of the transceiver into the charging unit. The latch mechanism prevents damage to the plug connectors by exerting a predetermined constant insertion force, independent of the force employed to seat the transceiver into the charging unit, in mating the plug connectors. The latch mechanism includes a release lever which provides a mechanical advantage to the operator during the initial portion of its release movement thus compensating for the gripping effect of the plugs with their mating connectors.

Abstract: An apparatus and method for recharging a rechargeable battery in a hand-held transceiver while maintaining communications capability through the transceiver. The battery charger is housed in a charging unit to which the transceiver can be removably attached. A dual-mode charging circuit generates a first voltage during transmit mode and a second, higher voltage during receive mode, and includes a DC-DC converter for generating the second voltage. The charger includes a push-to-talk (PTT) switch and mode control circuitry for simultaneously controlling the operating modes of the charger and transceiver, and additionally includes a separate microphone, speaker, and audio and RF amplifiers for providing greater RF power and audio power while the transceiver battery is being recharged.