Abstract: An interface device is made connectable to a printer parallel port of a computer and contains a memory device addressed by print data received from the computer. The device further includes an apparatus for generating a remocon code to remote-control controlled equipment on the basis of the data addressed in the memory device and which sends said code to the controlled equipment.

Abstract: An interface device includes connections to a printer port of a computer apparatus, and logic circuitry for selecting a particular sensor from among one or more sensors based on data from the computer apparatus. A signal is fed back to the printer port by way of the port connections based on the output of the sensor selected by said logic circuitry.

Abstract: A push-pull amplifer circuit using bipolar transistors in which non-linear distortion caused by the base-emitter voltages of the amplifying transistors of the circuit is eliminated without the use of negative AC feedback and in which variations in a DC output level at the output terminal of the amplifier are detected and fed back to the input side of the amplifier whereby the stability of the circuit at very low frequencies is remarkably improved. A first amplifier stage includes a first transistor having a base to which an input signal is applied and a second transistor the base of which is coupled to an output of the first transistor with the second transistor being of the opposite conductivity type of the first transistor. A current mirror circuit supplies currents to the first and second transistors with the currents thus supplied having a constant ratio. A second amplifying stage is provided having the same construction.

Abstract: A push-pull amplifier circuit using bipolar transistors in which non-linear distortion caused by the base-emitter voltages of the amplifying transistors of the circuit is eliminated without the use of negative AC feedback and in which variations in a DC output level at the output terminal of the amplifier are detected and fed back to the input side of the amplifier whereby the stability of the circuit at very low frequencies is remarkably improved. A first amplifier stage includes a first transistor having a base to which an input signal is applied and a second transistor the base of which is coupled to an output of the first transistor with the second transistor being of the opposite conductivity type to the first transistor. A current mirror circuit supplies currents to the first and second transistors with the currents thus supplied having a constant ratio. A second amplifying stage is provided having the same construction.

Abstract: A low-noise wide-band bipolar transistor amplifier in which distortion caused by non-linear transistor operating characteristics is substantially eliminated. An input signal is coupled to the base of a first transistor connected in an emitter follower configuration with the signal formed at the emitter of the first transistor coupled to the base of a second transistor. Currents are supplied to the first and second transistors by a current mirror circuit in such a manner that a ratio of the current supplied to the first transistor to the current supplied to the second transistor is made constant. An output signal is produced in response to current variations in a transistor of the current mirror circuit which supplies current to the second transistor.

Abstract: An equalizer amplifier in which non-linear distortion is substantially eliminated. An input signal is applied to the base of a first transistor the output of which is applied to the base of a second transistor of the opposite conductivity type to the first transistor. Currents are supplied to the first and second transistors in a constant ration. The output from the circuit is provided in response to current flowing in one of the first and second transistors. At least one of the amplifier gain determining elements has a reactance component which varies depending on frequency.

Abstract: An amplifier circuit in which the non-linear distortion of the amplifier transistors caused by non-linear base-emitter input and output characteristics is eliminated without the use of negative feedback. A first transistor and a second transistor of opposite conductivity type are coupled with the output of the first transistor connected to the base of the second transistor and with an input signal applied to the base of the first transistor. Currents are applied to the first and second transistors, such as with the current mirror circuit, in such a manner that the ratio of the currents is a predetermined constant value. Bias voltages are applied to the circuit such that the ratio of the collector-emitter voltage of the first transistor to the collector-emitter voltage of the second transistor is the reciprocal of the predetermined constant value.

Abstract: A grounded-source field-effect transistor amplifier circuit in which a constant current source is coupled to the source resistor to drain a current therethrough in addition to the normal source current with the amount of current chosen to equalize characteristics among different transistors. In a preferred application, two such transistors are coupled as a complementary pair with their drains connected to the inputs of a push-pull output stage. A variable resistor may be connected between the sources with its wiper connected to ground. A feedback resistor may be coupled between the output of the push-pull stage and the wiper of the variable resistor.

Abstract: A transistor amplifier having a first amplifier circuit with a first transistor having applied to its control electrode an input voltage. The ratio of the output voltage of the first transistor to the input voltage is approximately one. A second transistor circuit has a second transistor with its control electrode being directly supplied with the output voltage of the first transistor. The first and second transistors are bipolar transistors of the same type of conductivity with the respective bases used as the control electrodes.

Abstract: A circuit for detecting a DC signal in the output of an audio amplifier 1 and for uncoupling a speaker SP in response thereto comprises a low-pass filter 2 whose output is coupled to one input of differential amplifiers 5, 6 whose other inputs are unbalanced by respective positive and negative threshold biasing potentials E.sub.1, E.sub.2. The differential amplifiers are directly connected to respective current mirror circuits 7, 8, and their high impedance side collector outputs are applied to the inputs of an OR circuit whose output in turn controls the speaker uncoupling.