Abstract: A 12 volt input is supplied to a timer providing a square wave output with an approximately 50% duty cycle. The output is applied to the bases of a pair of transistors and the collectors of the transistors conduct when a drive motor is in either the forward direction or the reverse direction. During the time that a particular transistor is conducting, its collector current rises to a point of cutoff. At this time, energy stored in a transformer circuit is released to the secondary of the transformer circuit. To regulate the increase in voltage in the secondary, diode clamping is accomplished by a common string of zener diodes connected to the output of the secondaries of th transformer circuits and to the emitters of the transistors. By adding additional zener diodes in the secondary circuits of either of the transformer circuits, a change in the high voltage output for that particular transformer is accomplished.

Abstract: A precision voltage reference comprising an IC chip having a Zener diode connected to the input of an operational amplifier. Variations in output with temperature are minimized by selectively controlling the Zener current in accordance with temperature. The current is controlled by a resistive circuit including a thermistor connected in parallel with the Zener. A method of trimming the voltage reference is provided wherein an optimum quiescent operating current is determined based on voltage and current measurements at two different temperatures.

Abstract: A voltage divider used to supply multiple reference voltages is energized electrically, in shunt, by a constant voltage generator and, in series, by a constant current generator. The magnitude of current supplied by the constant current generator determines the voltage drops across successive resistor stages of the voltage divider, while the magnitude of voltage supplied by the constant voltage generator determines the voltage level, with respect to ground, of the voltage-divider tap to which the constant voltage generator is connected. Since these two generators are independent of each other, it is possible to independently control the range and zero point settings of a voltage divider.

Abstract: Transducers of the average responding RMS indicating type are disclosed that are particularly useful for monitoring currents and voltages in a power distribution network. The transducer includes transformer, inductively compensated voltage divider, active filter and output amplifier circuits electrically connected to provide a transducer having excellent long term transducer stability so that the transducer requires no calibration, and a highly accurate readout over a wide temperature range.

Abstract: An improved voltage reference circuit is provided comprising a series combination of a Kelvin-connected buried zener diode and a transistor. The collector of the transistor is connected to the first anode of the diode while the base of the transistor is connected to the second anode of the diode. This connection provides compensation for temperature and voltage variations in the zener diode caused by anode parasitic resistances and external temperature changes.

Abstract: A series shunt regulator circuit suitable to be fabricated in monolithic circuit form for providing a regulated output voltage and having a low input to output voltage differential thereacross. The regulator is comprised of a passive PNP current mirror circuit including a pair of PNP emitter area ratio transistors whereby the collector current of the output transistor of the pair of PNP transistors which is coupled in series with the output of the regulator circuit is equal to the value of N times the collector current of the second one of said pair of PNP transistors where N is the ratio of the emitter areas. A constant current source sinks a small reference current from the second transistor such that the output current from the regulator circuit is equal to the value N times this reference current.

Abstract: A circuit which performs regulator or limiter functions at current and voltage levels below the operating ranges of conventional zener diodes. The output of an op amp is connected through a diode to a main input terminal which may be connected between a power source and one end of a load resistor. A first current limiting resistor connects the main input terminal to the inverting input of the op amp. A second current limiting resistor connects the non-inverting input of the op amp to the wiper terminal of a potentiometer which permits adjustment of a simulated zener voltage V.sub.z. A pair of supply voltage terminals of the op amp are connected to voltages V.sub.cc and V.sub.ee, respectively. A pair of fixed terminals of the potentiometer are also connected to voltages V.sub.cc and V.sub.ee, respectively. The simulated zener voltage V.sub.z may be positive or negative, and may be adjusted to any value within limits determined by voltages V.sub.cc and V.sub.

Abstract: A protection circuit for a semiconductor substrate comprises a semiconductor substrate of a first conductivity type, a first region of a second conductivity type formed in the semiconductor substrate, a second region of the first conductivity type formed in the first region, a means for applying a reverse bias to a PN junction formed between the semiconductor substrate and the first region and a PN junction formed to the first and second regions, and a wiring for electrically connecting the second region to the semiconductor device to be protected.

Abstract: A two transistor voltage reference circuit controls the ratio of the current densities of two transistors by a negative feedback loop. A voltage corresponding to the difference in the base-to-emitter voltages of the two transistors is developed which has a positive temperature coefficient (TC) and which is connected in series with the base-to-emitter voltage of one of the two transistors having a negative TC. The circuit parameters are selected so that the resultant combined voltage has a predetermined, composite TC. A zener diode is included in the negative feedback loop and arranged to have a TC which cancels the predetermined composite TC to develop a reference voltage having a high magnitude that has minimal variation with temperature change.

Abstract: Butted guard band CMOS circuits have a typical breakdown of about 7 volts. It is often desirable to operate circuitry from supplies greater than 7 volts. For example, 9 volts is a commonly used supply value. An isolated zener diode is fabricated into a CMOS integrated circuit so as to develop a voltage drop equal to guard band breakdown. The zener voltage is coupled by way of a diode-connected transistor to the operating circuitry. The diode drop substracts from the zener voltage so that the circuitry is always operated at a voltage below its breakdown.

Abstract: First and second input currents to a three-phase AC induction motor of either delta or wye winding configuration are directly regulated by a pair of phase-triggered, gate-controlled, semiconductor switches series-inserted between the motor and two phases of its three-phase AC power source, the third input current being the Kirchoff resultant of the two regulated input currents. The half-cycle firing points or firing angles of the gate-controlled switches are varied together to apply more or less power to the motor as a function of mechanical load to optimize the power factor of the motor. Voltage imbalances in the motor windings caused by directly regulating only two of three input currents are tolerable due to the current limiting effect of the gate-controlled switches when the induction motor is at less than full mechanical load, such current limiting minimizing heat losses (I.sup.2 R) caused by the voltage imbalance condition.

Abstract: A transistorized voltage regulator has two outputs, one for high current loads and another for low current loads, to minimize drift of the output.

Abstract: The invention relates to a transistorized voltage limiter as a dipole having in the conduction direction the characteristic similar to that of the Zener diode. When low voltage is involved, this transistorized voltage limiter can replace the Zener diode in various electronic circuits for the stabilization of voltage. Moreover, it has a small dynamic resistance and eliminates noises in the curve.

Abstract: A solar recharged power supply circuit for a lighting system which circuit includes a rechargeable power source, a solar powered recharger connected to that rechargeable power source and which circuit prevents discharge of that rechargeable power source through the solar powered recharger during times when the recharger is inactive; prevents overcharging of that power source; prevents discharging that power source below a predetermined level; and automatically connects and disconnects the lighting system to and from the rechargeable power source.

Abstract: A temperature-compensated IC voltage reference comprising a Zener diode serving as the principal voltage source, in combination with a compensating voltage source including a transistor providing a forward-biased junction, and control circuitry. The compensating voltage is summed with the Zener voltage to produce a reference voltage. The compensating voltage source includes an adjustment element for trimming the reference output to a specified voltage, and the control circuitry operates with that adjustment element to automatically produce optimum temperature compensation when the output has been adjusted to the specified value.

Abstract: A compensated reference voltage source for providing a stable output voltage despite variations in operating voltage. The circuitry includes a series arrangement of a first resistance, a Zener diode, and a second resistance connected between a source of operating voltage and ground. A first transistor has its collector connected to the juncture of the first resistance and the Zener diode, its base connected to the juncture of the Zener diode and the second resistance, and its emitter connected to ground. A second transistor has its base and emitter connected directly to the corresponding electrodes of the first transistor and its collector connected to an output terminal. A third transistor has its collector connected to the source of operating voltage, its emitter connected to the output terminal, and its base connected to the collector of the first transistor. The base-emitter characteristics of the transistors are essentially identical.