Abstract: Apparatus and method for allowing an operator of a transit vehicle to make public address announcements to passengers internal and external to the vehicle. The safety of the vehicle and passengers is maintained through providing a hands-free directional microphone having noise canceling characteristics. The microphone is used as an input device for receiving an audio signal and provides the signal to a processing module that converts the signal into a digital signal. The digital signal is then processed by a digital signal processor to cancel undesirable noise common to a transit vehicle. The noiseless signal can then be converted into an analog signal and recorded within the memory of the public address system where, upon needed, the signal can be transferred to an output device such as a speaker system internal or external to the vehicle. After playback, the recorded message can also be easily repeated by means of a repeat switch.

Abstract: Apparatus and method for allowing an operator of a transit vehicle to make public address announcements to passengers internal and external to the vehicle. The safety of the vehicle and passengers is maintained through providing a hands-free directional microphone having noise canceling characteristics. The microphone is used as an input device for receiving an audio signal and provides the signal to a processing module that converts the signal into a digital signal. The digital signal is than processed by a digital signal processor to cancel undesirable noise common to a transit vehicle. The noiseless signal can then be converted into an analog signal and recorded within the memory of the public address system where, upon needed, the signal can be transferred to an output device such as a speaker system internal or external to the vehicle. After playback, the recorded message can also be easily repeated by means of a repeat-switch.

Abstract: Apparatus and method for allowing an operator of a transit vehicle to make public address announcements to passengers internal and external to the vehicle. The safety of the vehicle and passengers is maintained through providing a hands-free directional microphone having noise canceling characteristics. The microphone is used as an input device for receiving an audio signal and provides the signal to a processing module that converts the signal into a digital signal. The digital signal is than processed by a digital signal processor to cancel undesirable noise common to a transit vehicle. The noiseless signal can then be converted into an analog signal and recorded within the memory of the public address system where, upon needed, the signal can be transferred to an output device such as a speaker system internal or external to the vehicle. After playback, the recorded message can also be easily repeated by means of a.repeat-switch.

Abstract: A deflection device having a longitudinal configuration is fixed at one of its ends to a base supporting structure and is responsive to a first electrical signal from a control network to move the other of its ends in a first direction. The arm assembly can include at least one piezoelectric crystal having characteristics for deflecting in response to the first signal and for oscillating in response to abrupt changes in the magnitude of the first signal. This deflection device is particularly adapted for use as a probe for testing electrical circuits having a plurality of contact points coated with an insulating material. A probe tip can be disposed in proximity to the second end of the device so that the deflection of the crystal provides the tip with kinetic energy for penetrating the insulating material to provide electrical contact with one of the contact points. A second signal can then be introduced to the probe tip to test the electrical circuit.

Abstract: An electronic control device is connected in the power supply line to an electrical appliance to limit the amount of time the appliance can be used. In the illustrated embodiments, the invention permits a television to be put under parental control in order to limit the viewing time of each child in the family to a predetermined "allowance," for example, ten hours per week. The allowance is automatically refreshed at the end of each week. A current sensing circuit is included in the device to enable the device to monitor the on/off status of the television under control. The provision of the on/off information enables the control device to operate with numerous advantages, including permitting each child to simply turn off the television when he has completed his viewing without the necessity of "signing off" at the control device.

Abstract: A percussion drilling tool assembly is provided which operates under fluid pressure to reciprocating a hammer, the hammer is disposed in a barrel assembly and operates to strike an anvil bit shank to cause the bit to thereby penetrate a rock substrate material of central fluid passage through the drill stem of the assembly and through the reciprocating hammer allows a flushing fluid to be used with the drilling assembly to flush cuttings from the hole up and around the drill stem simultaneously with and separate from the fluid operating system for reciprocating the hammer.

Abstract: A method for producing a universal printed circuit board blank and the resulting universal printed circuit board blank are described. An array of pads and traces are printed on the surface of the board. The traces electrically interconnect evey pad to every other pad. Subsequent processing steps remove selected traces so that only certain particular pads remain connected to certain other pads as required by the circuit design, functioning and layout of the electronic components intended for use with the board.

Abstract: A percussion drilling tool assembly is provided which operates under fluid pressure to reciproce a hammer, the hammer is disposed in a barrel assembly and operates to strike an anvil bit shank to cause the bit to thereby penetrate a rock substrate material. A central fluid passage through the drill stem of the assembly and through the reciprocating hammer allows a flushing fluid to be used with the drilling assembly to flush cuttings from the hole up and around the drill stem simultaneously with and separate from the fluid operating system for reciprocating the hammer. The drill stem includes intake and exhaust passages for pressured working fluid as well as a mud passage for the flushing fluid or mud, the drill stem is made up in sections connected to form a string which extends the length of the hole and provide the pressured working fluid and mud to the pneumatic tool connected at the end of the drill stem.

Abstract: A construction suitable for incorporation into a display device, reflector, or the like. The construction employs a closed loop of material having elongated side wall portions. The loop is generally cross sectionally H-shaped. A flange or the like may project laterally outwardly from one side wall portion of the loop. A pair of plates are provided, each plate having a groove formed about the perimeter of the inner surface thereof and being adapted to nest matingly in a different lateral opposed side face defined by the loop. The plates are directly interconnected together when rested in the loop and interlock over the inside legs of the loop.