A tone signal detecting circuit includes a sampling circuit, a storage circuit, and a comparing circuit. The sampling circuit samples a tone signal at a sampling rate N times (N is a natural number) higher than a frequency f of the one signal. The storage circuit stores M (M is a natural number) latest values of time series data from the sampling circuit. The comparing circuit compares a plurality of polarity patterns expected on the basis of a tone signal with polarity patterns stored in the storage circuit and outputting coincidence outputs.
An object of the present invention is enhancing a capability of integration of a frequency finding circuit for finding a frequency of an input signal. A signal sampling circuit (21), sampling the input signal, utilizes a sampling signal (G) to convert the input signal into a sampled input signal (S) and inputs it to the frequency finding circuit. A resultant signal (K) from the frequency detecting circuit represents a specific frequency component contained in the input signal and is compared with a specified threshold value by a voltage comparator (25). Although a deciding signal (P) is produced as a result of the comparing, it contains unrequired components other than a sampling period. In order to eliminate the needless components, after sampling the deciding signal (P) in accordance with the sampling signal (G) again, an output circuit (50) latches it. The output circuit (50) includes a latch circuit (26) operating in accordance with the sampling signal G. Since the latch circuit is substitutional for a prior art sample/hold circuit, a capacitor and an external terminal connecting it, both of which are required by the sample/hold circuit, are no longer needless.
A ringing tone signal detecting circuit detects a ringing tone signal from a received signal of the echo canceler type which is supplied from a subscriber line through a hybrid circuit. The ringing tone signal detecting circuit has a sampler for sampling the received signal at a predetermined sampling frequency, a comparator for comparing an output signal from the sampler with a predetermined threshold value and producing a binary digital signal, a plurality of first through nth delay circuits for delaying the binary digital signal from the comparator for 1 through n sampling times, respectively, and a frequency detector for detecting a ringing tone signal from the binary digital signal from the comparator and output signals from the first through nth delay circuits. The circuit has particular use in detecting the ringing tone signals in the 2B1Q signaling code scheme.
An actuator assembly in a disc drive includes a track accessing arm, a load beam and a slider. A proximal end of the load beam is mounted to the track accessing arm and a distal end of the load beam carries the slider proximate to a rotatable data storage disc. The load beam transmits a load force to the slider in the direction of the data storage disc. A support beam extends from the track accessing arm and supports a load force reducer between the support arm and the load beam. The load force reducer is operatively coupled between the support beam and the load beam for reducing the load force during take-off and landing of the slider relative to the disc surface.