Patents by Inventor Hisashi Togari

Hisashi Togari has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 4540953
    Abstract: A gain control circuit is disclosed. In accordance with the preferred embodiment of the invention, a negative feedback amplifier is connected between a reference voltage and a variable impedance circuit which controls the voltage to the input of a signal amplifier whose output defines the desired output voltage. The variable impedance circuit varies the input voltage to the signal amplifier as a function of the level of the output voltage appearing at the output of the signal amplifier. The output impedance of the negative feedback amplifier is chosen such that an A.C. signal appearing at its output end can be sufficiently attenuated. As a result, the input impedance to the variable impedance circuit is negligibly small with respect to an A.C. signal. As a result, the amplitude of the input signal is varied over a wide range in response to the impedance of the variable impedance circuit.
    Type: Grant
    Filed: February 28, 1983
    Date of Patent: September 10, 1985
    Assignee: Nippon Electric Company, Ltd.
    Inventors: Hisashi Togari, Shinji Miyata
  • Patent number: 4508979
    Abstract: The present invention relates to a single-ended push-pull type inverter. Such inverter in the prior art generated a large through-current flowing through series-connected output transistors. This large through-current caused not only a large power consumption but also an instability of the entire circuit including the inverter. The present invention improves these disadvantages by inserting a phase inverter stage having a current regulating function just before the output transistors and includes a first transistor having a base receiving an input signal, the phase inverter stage having an input end connected to the collector of the first transistor, a second and a third transistor connected in series, the bases of the second and third transistors being electrically connected, respectively, to the collector of the first transistor and output end of the phase inverter stage and an output terminal connected to the circuit portion connecting the second and third transistors.
    Type: Grant
    Filed: April 1, 1982
    Date of Patent: April 2, 1985
    Assignee: Nippon Electric Co., Ltd.
    Inventor: Hisashi Togari
  • Patent number: 4330757
    Abstract: The present invention prevents the destruction of an output transistor when the output terminal of a single-ended push-pull type power amplification circuit connects to a ground line or other section to form a short circuit. That is, the base-emitter of a current-detection transistor of the same conduction type as that of the transistor to be protected is connected between the base and emitter of the output transistor to be protected. The collector current of this current-detection transistor is applied to a current-voltage conversion means through a current mirror circuit, and the voltage of the current-voltage conversion means is compared with that of the output terminal by a comparator transistor. With the output of the comparator transistor, the supply of a base current to the transistor to be protected is stopped.
    Type: Grant
    Filed: August 9, 1979
    Date of Patent: May 18, 1982
    Assignee: Nippon Electric Co., Ltd.
    Inventors: Hirokazu Fukaya, Hisashi Togari