Abstract: A fire hose (100) includes one or more conductors (107) acting as a feed line that is integrally woven into the fire hose side wall (109) and extending at least partially along a predetermined length of hose. One or more slots (113) expose the conductor (107) for transmitting and receiving radio frequency (RF) energy. The RF energy is transmitted and received bi-directionally along into the conductor (107) along the length of the fire hose. This provides stations positioned along the fire hose to have enhanced two-way radio communication without the disadvantage of signal degradation due to a firefighter's location within a building.

Abstract: A battery charging system includes a battery pack (106) and charger (102). Battery pack (106) includes a selectable magnetic field generator (202) which is activated by radio controller (206) when radio (104) changes states. A Hall-effect switch (204) located in either charger (102) or battery (106) receives the magnetic field and informs charger monitor circuit (128) that radio (104) has changed states. This allows for charger (102) to modify the amount of current being provided to radio (104) via line (129). In a second embodiment, an infrared source (402) and an infrared detector (404) are used in place of selectable magnetic field generator (202) and Hall-effect switch (204).

Abstract: A battery charging system (200) comprises a battery pack (206) and charger (202). Battery pack 206 includes a thermistor (212) for determining the temperature of battery pack (206) and a zener diode (210)in parallel with the thermistor (212) for informing charger (202) of the current capacity of battery (206) or of another battery parameter. Charger (202) includes a transistor (220) and zener diode (214) for effectively switching between measuring thermistor (212) and zener diode (210) at charger input terminal (224). This effectively reduces the number of battery and charger contacts required to measure two battery parameters as compared to the prior art.

Abstract: A battery charging system (200) includes a field-effect transistor (212) as a current discharge protection device in order to prevent current from flowing from battery (222) to charger (202) when charger (202) is not charging or discharging battery (222). The field-effect transistor (212) also protects battery (222) in the case that the battery contacts are inadvertently shorted. When charger (202) is charging battery (222), field-effect transistor (212) is turned on, providing for reduced voltage drop across the device due to its low on resistance, and also allows for charger (202) to charge and discharge (condition) battery (222).

Abstract: A switch assembly (100) includes a key area (104) and a light reception section (114) for receiving light from input lightpipe (106) and providing some of the light to key area (104). Switch assembly (100) further includes an output lightpipe (122) and an optical conversion section (116) for modifying the light which is received by output lightpipe (122) when key area (104) is activated.

Abstract: A microphone assembly (134) includes a movable diaphragm (124) and a linear light gradient (130) which causes the movement of diaphragm (124) to be translated into a corresponding amplitude of light to be received at a photo-detector (116). Thereby providing for a fully optical microphone assembly which is immune to radio frequency interference and resistance losses.

Abstract: A battery charger (102) includes an input terminal (124) for receiving control signals from radio (104). The control signals are received by a charge controller (112) which provides a charge rate to radio battery pack (106) which is a function of the control signal. Radio (104) includes a controller (126) which can sense the state of the radio battery pack (106), as well as changes in the state of radio (104). Controller (126) can then modify the control signal sent to charger (102) and therefor the battery charge rate proved by charger (102) based on certain changes in the state of battery pack (106) or radio (104).

Abstract: A vehicular battery operated charger (202) for charging an electronic device such as a radio (204) includes a controller (218). Controller (218) determines the battery voltage of the vehicles battery (222) and compares it to a threshold level stored in controller (218). Charger (202) will automatically charge radio battery (206) as long as the voltage level of the vehicles battery (222) does not drop below the threshold level stored in controller (218).

Abstract: A battery charging system (10) includes a charging path (50) for charging batteries (14) which have a variety of different charging parameters requiring different optimum charging algorithms (58). The battery charging system (10) comprises a charging algorithm sensing circuit (30). At least one battery cell (14A, 14B) having a positive (23) and a negative terminal (27) and an optimum charging algorithm is to be charged. An impedance (R18) having two terminals and a value related to a predetermined charging algorithm of the cell approximating the optimum charging algorithm is coupled to one of the positive or negative terminals of the battery cell (14B). A capacitor (C72) combines with the impedance (R18) to form a characteristic related to the predetermined charging algorithm.

Abstract: Briefly, according to the invention, a tilt switch 30 comprises a body 20 including a substantially conical cavity. The substantially conical cavity has at least a portion 24 which is electrically conductive. The tilt switch further has an electrical contact 32 spaced from the conductive portion 24 of the cavity. Finally, a conductive ball 34 located within the cavity selectively interconnects the electrical contact 32 and the conductive portion 24 of the cavity when the tilt switch 30 is tilted.In another aspect of the invention, a jitter switch 40 comprises a body 50 including a substantially concave shaped cavity. The substantially concave cavity has a curved bottom surface having a conductive portion (48) thereon and a sidewall having a separate conductive portion (44) thereon. A conductive ball 46 within the cavity intermittently interconnects the conductive portion of the bottom surface 48 with the conductive portion on the sidewall 44 when the jitter switch 40 is in motion.

Abstract: A battery having a self testing feature for its intrinsic safety circuitry is provided. The battery uses light emitting diodes to indicate the operation of safety circuit in the battery. The safety circuitry of the battery may be tested by providing a short across the battery terminals, if the associated circuitry is operational the light emitting diode will light. This feature will also indicate, when the load across the battery is shorted.

Abstract: Battery charging apparatus for charging batteries having different optimum charging rates, and wherein there is included in the same housing with the battery an electrical element having a characteristic related to a predetermined charging rate of the battery. Terminals are provided on the housing for the battery and the electrical element, for connection to the charging apparatus, and the charging apparatus utilizes the value of the characteristic of the element to control the supply of charging current to the battery. The electrical element provided with the battery may be a resistor, and the charging apparatus connects the resistor in a circuit to develop a control potential which is utilized to control the charging current. This control potential operates through a regulator to control the current through a resistance which is connected to the base of a transistor which controls the charging current.