A switched multi-tapped transformer-based power conversion circuit is disclosed. A polarity alternator comprising dual switch devices controlled by a microprocessor selectively periodically impresses across a transformer's center-tapped primary winding a voltage from a battery to produce a modified square waveform. Each of the taps of the transformer's secondary winding synchronously selectively switched by the microprocessor to a common wired-OR junction where the discrete voltage levels combine to produce a stepped approximation of a stored sine waveform. The switching circuits for each of the taps comprises dual back-to-back series-connected FET switches with diodes shunting each FET's source and drain. The microprocessor periodically senses the voltage across the primary winding, calculates the voltage across the secondary winding based upon the predetermined turns ratio of the tap that is switched to the common junction and compares the calculated output voltage with a normalized memory-based sine wave representation, thereby to determine when to switch to another tap. The converter, which operates concurrently as an inverter and a charger, responds in real time to changing DC source and AC load conditions. A similar converter having a full-wave rectifier on the primary winding side of the transformer is connectable to an AC source and provides for the charging of a connected DC load.

Switched multi-tapped transformer power conversion method and apparatus

A low voltage series pass regulator configuration has an input terminal for receiving a predetermined input voltage and an output terminal operatively connected to a load. The regulator comprises at least one field effect transistor in a source follower configuration. The drain of the field effect transistor is operatively connected to the input terminal and the source is operatively connected to the output terminal which provides an output voltage across the load. In one embodiment of the present invention a current limiter is operatively connected between the source and a gate of the field effect transistor. In another embodiment of the present invention a comparator for comparing the output voltage to a first reference voltage is provided. The comparator supplies a control voltage, indicative of the value of the output voltage compared to the first reference voltage, to the gate of the field effect transistor. This output voltage is indicative of the current drawn by the load and causes the comparator to produce a control voltage on the gate which keeps the output voltage substantially constant.

Field effect regulator with stable feedback loop

An apparatus including an electrostatic discharge (ESD) protection device comprising a semiconductor having first, second and third regions arranged to form a transistor, wherein the first region is doped with a first impurity of a first conductivity type and is separated from the second region which is doped with a second impurity of a second conductivity type opposite the first type, and wherein a dimensional constraint of the regions defines an operational threshold of the ESD protection device. In one example, the separation between a collector and an emitter of a bipolar transistor defines a trigger voltage to cause the electrostatic discharge protection device to become conducting. In another example, a width of a bipolar transistor base controls a holding voltage of the electrostatic discharge protection device.

Electrostatic protection device

In a preferred embodiment, voltage control system and method which include providing voltage sensing and control circuitry which measures the output voltage of a battery and provides an output signal to a flow control valve to cause the flow control valve to reduce the rate of flow of electrolyte when the output voltage of the battery is below a desired level and to cause the flow control valve to increase the rate of flow of electrolyte when the output voltage of the battery is above a desired level. The flow control valve may be a binary controlled solenoid valve responsive to a pulse-width-modulated signal from the sensing and control circuitry.

Automatic voltage control system and method for forced electrolyte flow batteries

The invention relates to a power source circuit in which an output of a power source battery is converted by a voltage regulator constructed by a predetermined voltage regulating system and is output, an output voltage is divided by a resistance controller whose voltage dividing resistance value can be discontinuously adjusted, the divided voltage is input to the voltage regulator, and thereby controlling an output voltage, wherein means for controlling a voltage changing speed of a resistor is connected in parallel with a predetermined resistance element of the resistance controller. With the above construction, a voltage drop and a deterioration of voltage regulating efficiency which easily occur in the case of changing the output voltage from a low value to a high value in a stepwise manner are reduced. Then, the life of battery is prolonged and, further, an erroneous warning of the battery life is prevented.

Power source device with control of voltage change speed

A combination of transistors, which can be integrally formed with an SCR is used to effect a turn-off. The magnitude of the turn-off pulse is less than that required to turn it on. When the entire circuit is self contained, only four leads to the device are required. Two of the leads handle the load current in the typical well known manner. The SCR turn-on is effected by a pulse applied to the gate through a third lead. A fourth lead is provided to turn the SCR off by causing an anode to cathode short across the SCR. This short is controlled by two transistors connected in an ''''inverted darlington'''' configuration.

Easily switched silicon controlled rectifier

A DC to DC converter for producing a constant voltage DC output signal which includes an unbalanced square-loop magnetic core inverter, a single silicon controlled rectifier for initiating a single complete cycle of said inverter upon the receipt of an input pulse signal, and a constant frequency pulse oscillator coupled to a control input of the silicon controlled output signal, which is subsequently half-wave rectified and filtered, each cycle of which having a constant average voltage amplitude The frequency of the pulse oscillator is lower than the freerunning frequency of the inverter, thereby producing an output pulse train having a constant average amplitude regardless of input voltage

Constant output voltage dc to dc converter

Circuit for measuring inductance or capacitance

A sea water battery is housed within a container which is open to sea water at the bottom and which has a controllable valve for allowing gas to escape from the top. The opening and closing of the valve are actuated, respectively, by predetermined lower and upper battery voltage limits so as to control the amount of water within the container to thereby regulate the output voltage.

Joseph M Marzolf

Papers

Easily switched silicon controlled rectifier

Constant output voltage dc to dc converter

Circuit for measuring inductance or capacitance

Long life regulated sea water battery

D.c. voltage regulator employing a zener diode