Power control system

A power control system comprising:

• (a) a control circuit having input and output terminals, said control circuit receiving an input AC voltage at said input terminals and supplying an output AC voltage at said output terminals, said control circuit comprising:
• (1) a switching element having a fully conducting state;
• and
• (2) variable energy diverting means which can divert variable amounts of energy to said output terminals when said switching element is not in its fully conducting state;
• and
• (3) means for controlling said variable energy diverting means as a function of a sensed circuit parameter of said control circuit;
• wherein said parameter is said output AC voltage.

A power control system comprising:

• (a) a control circuit having input and output terminals, said control circuit receiving an input AC voltage at said input terminals and supplying an output AC voltage at said output terminals, said control circuit comprising:
• (1) a switching element having a fully conducting state;
• and
• (2) variable energy diverting means which can divert variable amounts of energy to said output terminals when said switching element is not in its fully conducting state;
• and
• (3) means for controlling said variable energy diverting means as a function of a sensed circuit parameter of said control circuit;
• wherein said parameter is said input AC voltage.

A power control system comprising:

• (a) a control circuit having input and output terminals, said control circuit receiving an input AC voltage at said input terminals and supplying an output AC voltage at said output terminals, said control circuit comprising:
• (1) a switching element having a fully conducting state;
• (2) variable energy diverting means which can divert variable amounts of energy to said output terminals when said switching element is not in its fully conducting state;
• and
• (3) means for controlling said variable energy diverting means as a function of a sensed circuit parameter of said control circuit;
• wherein said parameter is an output current at said output terminals.

A method of controlling the power from an AC source that is supplied to a load, comprising the steps of:

• (1) closing a switch element in series circuit relationship with said source and said load;
• (2) opening said switch element after a first predetermined period of time and activating a main energy divertor to divert energy to said load;
• (3) activating a variable energy divertor after a second predetermined period of time to divert additional energy to said load;
• (4) stopping said diverting of energy by said main energy divertor and said variable energy divertor by closing said switch element;
• and
• (5) repeating steps (2) through (4) at least once for each half-cycle of the AC source voltage.

A power control system comprising:

• (a) a load;
• and
• (b) a power control circuit having
• (1) a pair of input terminals for receiving an input AC voltage from a power source and a pair of output terminals for supplying an output AC voltage to said load;
• (2) main energy diverting means connected to at least one of said output terminals;
• and
• (3) variable energy diverting means connected to at said least one of said output terminals and input terminals, said variable diverting means including a controllably conductive device which has at least three modes of operation, said modes including:
• (A) an on mode wherein said output voltage is substantially the same as said input voltage;
• (B) an off mode wherein said output voltage is supplied to said output terminals substantially only from energy stored in said main energy diverting means;
• and
• (C) a current source mode wherein the conductance of said controllably conductive device is varied so as to obtain a substantially constant output current through said controllably conductive device during at least part of each cycle of said output AC voltage.

A power control system for being connected between a source of power providing an AC input voltage and a load for receiving an AC output voltage, comprising

• a controllably conductive device in series circuit relationship with at least one impedance;
• said impedance being insertable between said source of power and said load, during at least one insertion period in each half-cycle of said AC input voltage, said insertion period having a selected phase relationship with said input AC voltage, said insertion period being controlled by controlling the conduction of said controllably conductive device;
• the duration of the insertion period and the phase relationship of the beginning of the insertion period to said AC input voltage being variable to allow the power delivered from said source of power to said load to be altered;
• and
• the maximum current flowing through said controllably conductive device, after the beginning of the insertion period, being controlled to limit the rate of change of AC output voltage to keep said rate of change below a predetermined value.

A power control system for receiving at an input terminal an input line voltage and supplying at an output terminal an output load voltage having a predetermined waveform, comprising:

• (a) a main divertor connected at least to said output terminal;
• (b) a control circuit;
• and
• (c) a variable divertor connected to said input and output terminals, said variable divertor including a controllably conductive device which is controlled by said control circuit to have at least three modes of operation, said modes including:
• (1) an off mode such that said output load voltage is supplied to said output terminal substantially only by said main divertor,
• (2) an on mode such that said output load voltage is substantially the same as said input line voltage, and
• (3) a current source mode wherein the conductance of said controllably conductive device is controlled so as to obtain a transition of said output load voltage between said off mode and said on mode.

A power control system for receiving AC power input at an input terminal and supplying AC power output having a desired voltage waveform at an output terminal, comprising:

• (a) a capacitor interconnecting said input and output terminals;
• (b) a variable divertor circuit interconnecting said input and output terminals in parallel with said capacitor, said variable divertor circuit including:
• (1) a series connection of a semiconductor element and an impedance, said series connection being connected in parallel with said capacitor;
• (2) a drive circuit for driving the semiconductor element so as to control its conductance;
• (3) a circuit for sensing the current carried by said semiconductor element and limiting such current by providing a current-limiting signal to said drive circuit;
• (4) a circuit for sensing the voltage across said semiconductor element and generating a voltage-indicating signal;
• (5) a circuit for determining whether said voltage sensed by said voltage sensing circuit is excessive and in response generating a fault protection signal;
• and
• (6) a notch position circuit for receiving said voltage-indicating signal and said fault protection signal and providing a control signal for controlling said drive circuit to generate said desired output voltage form;
• (c) a phase control circuit for being operated by a user so as to generate a phase control signal representative of said desired output voltage waveform;
• and
• (d) a phase control interface for receiving said phase control signal and in response providing a notch position control signal to said notch position circuit for further controlling said drive circuit to generate said output voltage waveform.