Left and right stereo power amplifiers receive power from the 12-volt D.C. automobile supply bypassed by a single capacitor for both amplifiers and energize left and right loudspeakers in series with the junction of the series-connected speakers coupled to ground through a capacitor that allows the left and right speakers to be independently driven by the left and right power amplifiers, respectively, by spectral components above the crossover frequency determined by the speaker impedance and th...

An amplifying circuit has a plurality of first signal input circuits for multi-channel input, a signal output circuit receptive commonly of outputs of these signal input circuits, and a switching circuit for selecting one of the first signal input circuits. A second signal input circuit has an input terminal held at a fixed potential and an output terminal connected to the signal output circuit and is operative during a selecting transient period of the plurality of first signal input circuits.

An amplifying circuit comprising an input terminal to which an alternating current signal is applied; a first transistor; a second transistor where one of the first and second transistors is a NPN transistor and the other is a PNP transistor; an output terminal to which is connected the respective collectors of the first and second transistors means for operating the second transistor as a constant current source; and connecting means for connecting the alternating current signal at the input te...

Torque is transmitted from the input member of a clutch to a primary shoe when the primary shoe is pressed into frictional engagement with the input member by compression springs. When initially turned by the input member, the primary shoe moves a series of balls angularly along inclined ramps to cause a secondary shoe to shift into frictional engagement with the input member and transmit torque to the output member of the clutch. A brake acts through the shoes to retard the output member when t...

A wide-band and high-gain differential amplifier adapted to amplifying transmitted optical signals of the GHz band is constituted by GaAs MESFET's. Two MESFET's Q1 and Q2 are differentially connected to each other. Drains of Q1 and Q2 are connected to load resistances R.sub.L and R.sub.L via a source-drain path of other MESFET's Q3 and Q4 whose gates are grounded in AC-wise. Current by-passing means 4, 4 are connected to the sources of other MESFET's Q3, Q4. DC bias currents of the differential ...

In an amplifying circuit of current subtraction type, a first output of a differential amplifier is coupled through a first transistor to an output electrode of an output-side transistor of a current mirror circuit and a second output of the differential amplifier is coupled through a second transistor to an input electrode and an output electrode of an input-side transistor of the current mirror circuit so that an output current based on a difference between the first output and the second outp...

In an amplifying circuit having a plurality of amplifier stages which are DC-coupled, and in which an AGC voltage is applied to one of the earlier amplifier stages for providing an AGC operation; changes in the DC level of a later amplifier stage resulting from the AGC operation are detected, and such detected changes in the DC level are cancelled at the DC-coupling between the earlier and later amplifier stages.

An amplifying device for applying a DC bias current and a signal current to a load circuit includes a current supplying element for supplying a current to the load circuit, a control signal applying circuit for applying to the current supplying element a DC bias control signal defining the DC bias current supplied from the currenting supply element, and a signal applying circuit for applying to the current supplying element an electrical signal defining the signal current, wherein the rising and...

An amplifying circuit comprises a voltage-current converter for voltage-current converting an input signal to be amplified and a current-current converter including a first transistor (NPN), a second transistor (NPN), a third transistor (PNP) and a fourth transistor (PNP). Emitters of the first and third transistors are connected to each other, collector and base of the second transistor are connected to each other, collector and base of the fourth transistor are connected to each other, emitter...

A single stage amplifying circuit defined by a bipolar transistor differential pair, supplied from a constant current regulator, and with balanced collector load resistors. One balanced output is connected directly to signal common and, also, the circuit is powered from a supply that is isolated or floating with respect to the signal voltage common, achieving low output voltage levels of either polarity with significantly low distortion levels.