Abstract: Described is a digital signal processor including at least two memories, that is, a microprogram memory for storing a series of microinstructions for instructing a digital signal processing procedure, and a coefficient memory for storing coefficient data required for performing a series of arithmetic operations on the digital signal data. These data being transferred and written into said microprogram memory and said coefficient memory from a host computer system. The coefficient memory has at least two pages corresponding to the total memory area which may be addressed during digital signal processing to be effected by said microinstructions. Page selection of the coefficient memory may be performed from said host computer system.

Abstract: A process for preparing a press die comprises forming a metal overlaid on a base metal which is different in kind from the overlaid metal, and cutting the base metal together with overlaid metal into a predetermined shape.

Abstract: A signal processing system records and reproduces a music signal which varies repeatedly. The music signal is sampled at a given sampling period and pulse row obtained from the sampling is rearranged into a given pattern to achieve a new pulse row which is stored. For read out from a storage medium, a read-out means reproduces the original pulse row sequence and provides a wave form of the original music signal.

Abstract: A digital waveform generating apparatus includes a key assignor selecting a frequency of a signal to be generated, a number-setting circuit for generating a first data word corresponding to the selected frequency, a first memory for storing said first data word, a second memory for storing a second data word, an accumulator for accumulating the first data word onto the second data word stored in the second memory, so that the second data word stored in the second memory after accumulating represents the sum of the second data word immediately prior thereto added with said first data word, a waveform memory, preferably an ROM, for storing predetermined waveform data and for generating a waveform data output signal, and a control circuit for controlling such accumulating and progressively addressing the waveform memory in accordance with the stored second data word at the time of a timing signal.

Abstract: A fluid flow control system has a fluid source and plural flow pipes connected to the fluid source. Each of the pipes has an opening of a specific area corresponding to one of the bit orders of a PCM (Pulse Code Modulated) input signal. The flow-condition of the fluid through each of the pipes is controlled by the PCM signal without changing the PCM signal to an analog signal. The summation of the outflow from each of the pipes combines to produce an analog flow output signal in response to the PCM input signal.

Abstract: In a tone generating apparatus for an electrical music instrument having an array of switches corresponding to respective keys of a keyboard and which are selectively actuable by manipulation of the respective keys, a timing signal generator, preferably including a shift register, has a repetitive operating cycle and is connected with the switches for providing timing signals in response to actuation of the latter, with each of the timing signals occurring at a time during the operating cycle which corresponds to the position of the respective actuated switch in the switch array, an exponential signal generator provides an exponential signal in synchronism with the operating cycle of the timing signal generator, a sample and hold circuit receives the exponential signal and is operative to sample and hold a value of the exponential signal in dependence on the time of occurrence of a timing signal in the operating cycle, and variable frequency oscillator controlled in accordance with the value of the exponentia

Abstract: A pulse width modulation circuit which comprises a mixer for combining an input audio signal with a feedback signal and for developing a difference signal to feed to an integration circuit. The integration circuit is coupled to a pulse width modulator which has a sawtooth carrier input for modulating the input audio signal. The resulting pulse modulated signal is then fed to a pulse amplifier and a low-pass filter and finally to a load. The output of the low-pass filter is coupled back to the mixer.

Abstract: The power supply voltage of an amplifier is modulated by a signal having a waveform that corresponds, at least in selective parts, to the waveform of the signal being amplified by the amplifier.

Abstract: A frequency converter utilizing a novel four terminal semiconductor device having an emitter grounded current amplification characteristic which is V-shaped wherein the gate terminal of the four terminal device is biased to the low point of the emitter grounded current amplification characteristic and wherein a signal which varies in time is applied to the gate terminal to cause the emitter grounded current amplification factor to fluctuate at both sides of its low point. A tuning circuit is provided in series with the emitter-collector terminals of the four terminal device and is tuned to twice the frequency of the input signal applied to the gate terminal.

Abstract: A pulse width modulated (PWM) signal amplifier includes an input terminal supplied with an input signal to be modulated, a sawtooth wave generator, and a first amplitude comparator supplied with the input signal and with the output signal of the sawtooth wave generator to produce a first control signal each time the amplitudes of the both signals become equal. A bistable circuit having first, second and third terminals is provided, in which the first terminal is supplied with the first control signal. A subtracting circuit is connected to receive the input signal supplied to the input terminal and the output signal from the second terminal of said bistable circuit and to combine these signals subtractively. An integrating circuit integrates the output signal of the subtracting circuit.

Abstract: A pulse width modulated signal amplifier system includes a signal input circuit, an amplifier for receiving an input signal from the signal input circuit, a pulse width modulator for receiving an output signal from the amplifier and producing a pulse width modulated signal, and a phase splitter for receiving the pulse width modulated signal and producing a pair of corresponding pulse width modulated signals having different polarities to each other.

Abstract: A protective circuit for a pulse width modulated signal amplifier includes a signal input circuit, a carrier signal generator, a pulse width modulator for receiving both the output signals of the signal input circuit and the carrier signal generator and for producing a pulse width modulated signal, an amplifier for receiving the pulse width modulated signal and for amplifying it to drive a load through a low pass filter, a detecting circuit for detecting whether the pulse width modulated signal is present or not, or detecting DC voltage of undesirable duration produced at the output of the amplifier and for producing a control signal, and a protective circuit activated by the control signal for cutting off the operation of the amplifier.

Abstract: A pulse width modulated signal amplifier including a signal input circuit, a clock pulse generating circuit, a pulse phase modulating circuit and a pair of pulse transformers. The pulse phase modulating circuit is supplied with the output signal of the signal input circuit and the clock pulse signal in such a manner as to produce a pair of pulse signals having a phase difference which is proportional to the output signal level of the signal input circuit. Each primary coil of the transformer is supplied with a pair of pulse signals, and the secondary coils are connected so as to add and subtract the pulse signals respectively. A rectifying circuit is supplied with the output signals from the secondary coils so as to produce the finally constituted pulse width modulated signals where the width of the pulse is proportional to the output signal level of the signal input circuit. At the same instance it is applied to a load through a low pass filter.