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公开(公告)号：CA1061468A
公开(公告)日：1979-08-28
申请号：CA246336
申请日：1976-02-23
Applicant: SONY CORP
Inventor： HAMADA OSAMU
Abstract: PWM SIGNAL AMPLIFIER 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. A second amplitude comparator is supplied with the output signal of the integrating circuit and with a reference signal to produce a second control signal each time the amplitudes of signals applied to the second comparator become equal, the second control signal being applied to the third terminal of the bistable circuit to produce a PWM signal to be applied to a pulse amplifier.
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公开(公告)号：DE2839624A1
公开(公告)日：1979-05-17
申请号：DE2839624
申请日：1978-09-12
Applicant: SONY CORP
Inventor： HAMADA OSAMU
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 exponential signal which is sampled and held for providing an output oscillation having a frequency determined by a selectively actuated one of the switches.
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公开(公告)号：CA1044765A
公开(公告)日：1978-12-19
申请号：CA189731
申请日：1974-01-08
Applicant: SONY CORP
Inventor： HAMADA OSAMU
Abstract: A broadcast receiver having a tuner with a variable local oscillator for generating a local frequency signal, a divider for dividing the local frequency signal at a variable dividing ratio, a comparator for comparing the divided local frequency output with a reference signal by which the local oscillator frequency is controlled, a counter having a variable content by which the dividing ratio of the divider is determined for establishing the radio broadcast frequency to which the receiver is tuned, a pulse generator operative to vary the counter content, and a detector circuit for producing an audio signal in response to an output from the tuner., The broadcast receiver further provides with non-voltaic memory device for memorizing contents of the counter at the time when the counter contents change, means for reading out the signal stored in the non-voltaic memory means and presetting the read out signal in the counter when a power source for the receiver is made ON, and a muting circuit for muting the audio signal during the operation of counter for selection.
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公开(公告)号：CA1034214A
公开(公告)日：1978-07-04
申请号：CA223325
申请日：1975-03-27
Applicant: SONY CORP
Inventor： HAMADA OSAMU
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.
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公开(公告)号：CA1033818A
公开(公告)日：1978-06-27
申请号：CA238575
申请日：1975-10-29
Applicant: SONY CORP
Inventor： HAMADA OSAMU
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.
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Patent Agency Ranking
公开(公告)号：DE2742711A1
公开(公告)日：1978-03-23
申请号：DE2742711
申请日：1977-09-22
Applicant: SONY CORP
Inventor： HAMADA OSAMU
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公开(公告)号：CA1012612A
公开(公告)日：1977-06-21
申请号：CA225934
申请日：1975-04-30
Applicant: SONY CORP
Inventor： NAKAMURA HIDEO , OHSAWA MITSUO , HAMADA OSAMU
IPC: H01L21/331 , H01L21/8222 , H01L27/06 , H01L27/07 , H01L29/00 , H01L29/73 , H03B19/14
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公开(公告)号：DE2513909A1
公开(公告)日：1975-10-09
申请号：DE2513909
申请日：1975-03-27
Applicant: SONY CORP
Inventor： HAMADA OSAMU
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.
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