Abstract: A rodent repeller having an audio signal generator configured to generate a chattering sound that mimics a distressed rodent. The audio signal generator produces a variable sound frequency to generate the chattering sound of distressed rodents.

Abstract: A rodent repeller having an audio signal generator configured to generate a chattering sound that mimics a distressed rodent. The audio signal generator produces a variable sound frequency to generate the chattering sound of distressed rodents.

Abstract: A rodent repeller having an elongated body, an end cap, an apex, a power supply, a buzzer, and a buzzer transformer. Connection of the power supply to the audible signal generator via the audible signal generator transformer produces a signal in the form of a chatter sound that mimics a frightened rodent to discourage rodents from remaining in a vicinity of the rodent repeller. The rodent repeller can further utilize solar power.

Abstract: A rodent repeller having an elongated body, an end cap, an apex, a power supply, a buzzer, and a buzzer transformer. Connection of the power supply to the audible signal generator via the audible signal generator transformer produces a signal in the form of a chatter sound that mimics a frightened rodent to discourage rodents from remaining in a vicinity of the rodent repeller. The rodent repeller can further utilize solar power.

Abstract: A rodent repeller having an elongated body, an end cap, an apex, a power supply, a buzzer, and a buzzer transformer. Connection of the power supply to the audible signal generator via the audible signal generator transformer produces a signal in the form of a chatter sound that mimics a frightened rodent to discourage rodents from remaining in a vicinity of the rodent repeller. The audible signal can be amplified with perforations in the apex, a tympanic resonator in the elongated body, or both. The rodent repeller can further utilize solar power.

Abstract: A rodent repeller having an elongated body, an end cap, an apex, a power supply, a buzzer, an LED, an LED transformer, and a buzzer transformer. Connection of the power supply to the buzzer via the buzzer transformer produces a signal to discourage rodents from remaining in a vicinity of the repeller stake, and connection of the power supply to the LED via the LED transformer produces a visual indicator that the repeller stake is operable. The LED transformer receives a voltage from the power supply, and the voltage varies in amount from a high voltage to a low voltage. The LED transformer controls the amount of power to the LED such that the LED has a high brightness when the high voltage is received by the LED transformer and the LED has a low brightness when the low voltage is received by the LED transformer.

Abstract: A rodent repeller having an elongated body, an end cap, an apex, a power supply, a buzzer, and a buzzer transformer. Connection of the power supply to the audible signal generator via the audible signal generator transformer produces a signal in the form of a chatter sound that mimics a frightened rodent to discourage rodents from remaining in a vicinity of the rodent repeller. The audible signal can be amplified with perforations in the apex, a tympanic resonator in the elongated body, or both. The rodent repeller can further utilize solar power.

Abstract: Audio-visual systems including a motion picture film projector and a tape player, the film having optical cues and program reference notches for stopping film advancement, and the tape having start cues for starting film advancement. The optical stop cues are detected dynamically and with cue length discrimination. A program select control causes the system to search for a program reference notch and to ignore optical stop cue until the notch is detected. Other features include a pause-run control, a variable frame rate control with a single-frame advance option, and remote controls. Optical stop cue detection systems include a light transmissive system, a light reflective system, a polarized light system, and a colored light system.

Abstract: A system for automatically adjusting the threshold sensitivity of an FM receiver (muting) to prevent noise capture and reduce the effects of distortion due to multipath reception. A crystal controlled oscillator drives a suppressed carrier modulator which in turn delivers sideband signals at F/88 and -F/88, where F is the IF center frequency of 10.7 MH.sub.z. The sidebands are injected into the FM receiver between the IF amplifier output and the input of a quadrature detector (discriminator) and fall outside of the maximum .+-. excursion of FM modulation within the IF bandpass, but are separated from F by less than the adjacent channel spacing. Proper adjustment of the level of these sidebands prevents noise capture and reduces FM Multipath Distortion.