Abstract: An optical shutter operated device includes a reflector to reflect incident light and a liquid crystal light shutter interposed in front of the reflector. A photovoltaic cell is disposed behind the shutter and is illuminated by the incident light thereby supplying a control voltage to the liquid crystal light shutter for causing it to alternate cyclically between a relatively transparent state and a relatively opaque state.

Abstract: A plural-output switched current source, as may be used to provide current drive to inidividual display segments of an LED display. Each respective current source output is selectively operable from a respective low level I.sup.2 L signal source. Means are provided to reduce the tendency of the selective operation of one LED display segment to affect the brightness of the remaining LED display segments.

Abstract: A complementary field-effect transistor (FET) amplifier with means for controlling peak cross-over current. A substantially constant current is established in the drain-source conduction paths of a pair of reference transistors by degenerative feedback from the conduction paths to the respective gate electrodes thereof; wherein the reference transistors have similar characteristics to the respective amplifier transistors. The resulting sum of the gate-to-source voltages of the reference transistors is used to apply a bias voltage between the gate electrodes of the transistors in the FET amplifier so that the sum of the gate-to-source voltages of the amplifier transistors is equal to the sum of the respective gate-to-source voltages of the reference transistors during the cross-over current condition. Cross-over current is thereby limited to a predetermined value proportional to the substantially constant current established through the reference transistors.

Abstract: A current divider apportions current applied to the interconnected emitters of a pair of current-dividing transistors as their respective emitter currents in a ratio dependent upon the voltage applied between their bases. A first diode means and a resistor are connected in a series connection, which series connection is in parallel connection with a second diode means. Current is applied to this parallel connection in a poling to forward-bias the first and second diode means which exhibit a difference in offset potentials across said resistor. A voltage directly related to this difference is applied between the bases of the pair of current-dividing transistors to determine the ratio of their emitter currents.

Abstract: Emitter-coupled differential amplifier transistors have their collector currents differentially combined for application to a series regulator transistor in series with a potential divider network having first and second taps to the base electrodes of the emitter-coupled differential amplifier transistors, for completing a feedback loop which develops positive-temperature-coefficient voltages across resistor portions of the potential divider network. These positive-temperature-coefficient voltages augment negative-temperature-coefficient voltages developed across semiconductor diode means included in the potential divider network to provide for zero-temperature-coefficient voltages being developed across the potential divider network or a portion thereof.

Abstract: Within a relaxation oscillator of the type having a capacitor that is recurrently charged from a current source and then discharged through a silicon controlled rectifier upon reaching a threshold voltage thereacross, a switch is disposed to interrupt current flow between the current source and the capacitor whenever the SCR is conductive.

Abstract: Regulated current sources of a type comprising first and second transistors of complementary conductivity types having respective input and output electrodes, the output electrode of each direct coupled to the input electrode of the other to complete a regenerative feedback loop tending to increase conduction in both transistors. The increased conduction of the second transistor is sensed by the input circuit of an amplifier exhibiting increasing gain for increased signal sensed by its input circuit. The output circuit of this amplifier is connected to the input electrode of the second transistor to complete a degenerative feedback loop which counteracts the regenerative feedback loop at prescribed current levels to establish the level of current regulation.

Abstract: A regenerative latch switch conducts responsive to a RESET pulse to selectively divert applied input current from the input circuit of a current amplifier such as a current mirror amplifier. Responsive to an ensuing SET pulse conduction of the regenerative latch switch is interrupted, so applied input current flows to the input circuit of the current amplifier for amplification.

Abstract: A gain control circuit includes a first transistor with direct-coupled collector-to-base feedback converting current, applied to its collector, to logarithmically related voltage appearing between its emitter and base. This logarithmically related voltage is incremented or decremented by a voltage .DELTA.V.sub.1 proportional to T and applied to the emitter-base junction of a second transistor used as a logarithm of voltage to current converter, T being an absolute temperature close to that at which the first and second transistors are operated. .DELTA.V.sub.1 is developed as the potential drop across a resistive element R1, responsive to the output current of a current-to-logarithm-of-current converter circuit, making the conversion with a scaling factor proportional to T divided by the resistance R.sub.1 of resistive element R1. Accordingly, the gain setting of the gain control circuit is unaffected by change in T.

Abstract: A vertical sawtooth generator adaptable for integrated circuit application self-oscillates under control of a latch circuit. A circuit controls the linearity of the charging capacitor ramp voltage. High frequency components of the recurrent ramp occurring due to the retrace discharge current are reduced by controlling the discharge currents. The ramp rate is controlled by a single resistor external to an integrated circuit.

Abstract: Within a negative impedance network of the type which includes a current mirror amplifier having transistors in master and slave paths, a bias current is applied at the commonly connected control electrodes of the master and slave path transistors in inverse proportion to the voltage applied across the slave path and thereby a negative impedance characteristic is derived through the slave path.

Abstract: A vertical sawtooth generator adaptable for integrated circuit application self-oscillates under control of a latch circuit. A circuit controls the linearity of the charging capacitor ramp voltage. High frequency components of the recurrent ramp occurring due to the retrace discharge current are reduced by controlling the discharge currents. The ramp rate is controlled by a single resistor external to an integrated circuit.

Abstract: Within a relaxation oscillator of the type having a capacitor that is recurrently being charged from a current source and discharged through a silicon controlled rectifier upon reaching a voltage threshold thereacross, a switch is disposed to interrupt current flow through the SCR in response to the capacitor being discharged to a predetermined level.

Abstract: Within a relaxation oscillator of the type having a capacitor that is recurrently being charged from a current source and then discharged through a silicon controlled rectifier upon reaching a voltage threshold thereacross, the current flow to the gate of the SCR is amplified relative to that being supplied by the current source when the threshold voltage level is reached across the capacitor.

Abstract: An input signal to a buffer circuit is applied via the emitter-to-base junction of a transistor to a circuit which includes at least one additional semiconductor junction and a current source. The collector of the transistor connects to a second current source and to the buffer circuit output terminal. When the input signal exceeds a threshold value, determined by the number of semiconductor junctions in the circuit including the emitter-to-base junction, the transistor turns on and its collector current, which exceeds the capacity of the second current source, flows via the buffer circuit output terminal to the load circuit.

Abstract: A quasi-linear amplifier, wherein each of first and second current dividers maintains a constant ratio between drive currents to respective output transistor means and dummy output transistor means, uses regulation of the quiescent drive currents to the dummy output transistors to establish the quiescent drive currents to the output transistors. The quiescent drive currents to the output transistors are maintained at levels conditioning these transistors for Class AB amplification of signal currents.

Abstract: The voltage-to-current converter includes first and second transistors having their respective common electrodes arranged to receive between them the voltage to be converted to current. Their output electrodes have connections to first and second current supply means, as well as direct coupled feedback connections to their respective input electrodes. At least one of these feedback connections is via the follower action of a respective further transistor between its input and common electrodes, and converted output current is available at the output electrode of each further transistor. First and second resistances connect the common electrodes of said first and second transistors to a node supplied quiescent current by a third current supply means, and their combined resistance controls the voltage-to-current conversion gain.

Abstract: A circuit for improving the characteristics of a transistor connected in the common emitter amplifier configuration with a load includes an impedance connected across the base-emitter junction. A source of bias coupled to the impedance establishes the conductivity of the transistor. A second transistor of opposite conductivity type to the first and connected as a follower between the collector and base of the first transistor becomes active when the first transistor becomes highly conductive. The emitter follower closes a degenerative feedback loop, reducing the effect of the source of bias in causing increased conductivity of the first transistor.

Abstract: The emitter-to-base potential of a first transistor operated at predetermined current level is scaled up and applied as the emitter-to-base potential of a second transistor. The resulting collector current of the second transistor decreases with increasing temperature and is differentially compared against a current of opposing polarity to obtain an output current which changes polarity at a given temperature.

Abstract: An integrated injection logic (I.sup.2 L) device includes at least two gate structures. Each gate structure includes a first region of one type conductivity with an injector region and a base region of the opposite type conductivity disposed therein adjacent a surface thereof. A second region of the opposite type conductivity is disposed in each gate structure adjacent the surface of the first region between the injector and base region. The second regions are electrically-floating regions free of any contact electrode.