US 4,716,357 AGranted

AC voltage regulator with split primary switching

OwnerEdward Cooperinventor

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Abstract

An apparatus for AC line voltage regulation has an input port for connection to an AC source, an output port for connection to a load, and a transformer assembly connected between the input and output ports. The transformer assembly comprises a buck/boost winding and a primary winding wound about a common transformer core, and a switch arrangement for controlling the connection of the primary winding in circuit with the buck/boost winding. The switch arrangement is controlled by switch actuators responsive to a voltage sensor assembly to connect the primary winding in either of two possible conditions when the voltage is outside predetermined limits. The transformer assembly comprises either a step down transformer for reducing or bucking the output voltage or a step up transformer for boosting the output voltage according to the condition of the switch arrangement. The primary may comprise separate windings controlled by the switching assembly for connection in different configurations.

Claims21

Dependent claims

An apparatus for regulating an AC line voltage, comprising:

an input port for connection to a source of input AC voltage;
an output port for delivering a regulated voltage to a load;
transformer means for regulating the output voltage, comprising a buck/boost winding connected between the input and output port, a primary winding split into two oppositely wound portions each having a greater number of turns than the buck/boost winding, each primary winding portion being split into at least two winding parts and a common transformer core about which both windings are wound;
switch means for controlling the connection of the primary winding in circuit with the buck/boost winding, including means for selectively connecting the primary winding in different configurations in the circuit the switch means comprising first switch means for controlling connection of the two parts of one of the primary winding portions in series in the circuit in a first, boost configuration, and second switch means for controlling connection of the two parts of the other winding portion in series in the circuit in a second, buck configuration;
voltage sensing means for detecting the magnitude of the line voltage and for producing corresponding control signals when the line voltage varies outside predetermined limits;
and
switch controlling means responsive to the voltage sensing means control signals for closing said first switch means if the voltage is below the predetermined limits and closing said second switch means if the voltage is aboe the predetermined limits, the transformer means comprising a step up transformer in the first configuration and a step down transformer in the second configuration;
and
energy proportional current and voltage limiting means for limiting the current and voltage across the primary winding.

6 more elements

An apparatus for regulating an AC voltage comprising:

an input port for connection to a source of input AC voltage;
an output port for delivering a regulated voltage to a load;
a neutral line;
transformer means connected between the input and output port for controlling the output voltage level, comprising a buck/boost winding, a primary winding having more turns than the buck/boost winding, and a common transformer core about which both of the windings are wound, the buck/boost winding being connected between the input and output port;
switch means for controlling the connection of the primary winding in circuit with the buck/boost winding, comprising a first pair of switches for selectively connecting opposite ends of the primary winding to the buck/boost winding, and a second pair of switches for selectively connecting opposite ends of the primary winding to the neutral line;
voltage sensing means for sensing the voltage level at a chosen point in the apparatus;
switch controlling means responsive to the voltage sensing means for controlling said switches, comprising means for closing one of said first pair of switches and the opposite one of said second pair of switches in response to voltages below a first predetermined level so that said transformer means acts as a step up transformer, means for closing the other one of said first pair of switches and the other one of said second pair of switches in response to voltages above a second predetermined level so that said transformer means acts as a step down transformer, and means for closing both of said second pair of switches in response to voltages intermediate said two predetermined levels, and a further winding connecting between the buck/boost winding and the first pair of switches, the further winding being wound on the common transformer core and having a first portion wound in the same direction as the buck/boost winding and a second portion wound in the opposite direction to the first portion.

4 more elements

An apparatus for regulating an AC line voltage, comprising:

an input port for connection to a source of input AC voltage;
an output port for delivering a regulated voltage to a load;
a buck/boost winding connected between the input and output port;
a circuit common line with a neutral input port for connection to a neutral power input;
a primary winding assembly for selective connection in a plurality of different possible configurations to a connecting point between the input and output port, the configurations including a boost configuration in which the assembly is connected in circuit with the buck/boost winding to provide a step up transformer, a buck configuration in which the assembly is connected to provide a step down transformer, and a straight through configuration in which the primary winding assembly is terminated itself;
the primary winding assembly comprising a first, boost portion and a second, oppositely wound buck portion, each portion being split into at least two parts, one end of each of the winding portions being connected to said buck/boost winding connecting point, and switch means comprising a first pair of switches connecting the two parts of the boost portion, a second pair of switches connecting the two parts of the buck portion, and a common line connecting all the switches together;
voltage sensing means for detecting the magnitude of the input line voltage and for producing corresponding control signals when the voltage varies outside predetermined limits;
and
switch controlling means responsive to the voltage sensing means for controlling the switch means to connect the primary winding means in the boost configuration if the voltage is below the predetermined limits, to connect the primary winding means in the buck configuration if the voltage is above the predetermined limits, and to connect the primary winding means in the straight through configuration if the voltage is within the predetermined limits, the switch controlling means comprising means for closing the first pair of switches in response to voltages below the predetermined limits, closing the second pair of switches in response to voltages above the predetermined limits, and closing one switch of each pair to terminate one part of each of the winding portions to each other in response to voltages within the predetermined limits.

6 more elements

Dependencies are inferred from the claim text.