Abstract: A filter that includes an analyzer, thresholding circuit, and synthesizer. The analyzer generates a low-frequency component signal and a high-frequency component signal from an input signal. The thresholding circuit generates a processed high-frequency signal from the high-frequency component signal, the processed high-frequency signal having an amplitude of zero in those regions in which the high-frequency component signal has an amplitude that is less than a threshold value. The synthesizer generates a filtered signal from input signals that include the low-frequency component signal and the processed high-frequency signal. The filtered signal is identical to the input signal if the threshold value is zero. The analyzer is preferably constructed from a plurality of finite impulse response filters that operate on a small fraction of the input signal at a time.

Abstract: A filter that includes an analyzer, thresholding circuit, and synthesizer. The analyzer generates a low-frequency component signal and a high-frequency component signal from an input signal. The thresholding circuit generates a processed high-frequency signal from the high-frequency component signal, the processed high-frequency signal having an amplitude of zero in those regions in which the high-frequency component signal has an amplitude that is less than a threshold value. The synthesizer generates a filtered signal from input signals that include the low-frequency component signal and the processed high-frequency signal. The filtered signal is identical to the input signal if the threshold value is zero. The analyzer is preferably constructed from a plurality of finite impulse response filters that operate on a small fraction of the input signal at a time.

Abstract: This invention pertains to a security lock of the combination type for the ignition, hood and trunk compartments of an automotive vehicle. The proper sequential operation of a plurality of pre-selected push buttons associated therewith conditions the electrical system of the device to permit the conventional ignition key of the vehicle to be actuated to start the car engine, or to selectively operate switches to open the hood or trunk lid by means of solenoid latches. Each push button is provided with an arm which actuates a control shaft to a limited degree and is lockingly engaged by a lock bar to condition the electrical system to permit operation of the ignition key, or the trunk or hood switches when the proper sequential manipulation of the push buttons has been accomplished. When a single push button is actuated out of sequence, the lock bar is released and the entire system returns to a neutral condition.