Inductorless controlled transition and other light dimmers

A method of operation for a lamp dimmer, said lamp dimmer having an input, comprising the steps of:

• coupling a semiconductor power controlling means for modulating instantaneous voltage or current between an alternating current supply and an output suitable for a lamp load;
• inputting a first value via said input indicating a desired amount of power for said lamp load;
• determining at least a first phase angle of a half-cycle of the waveform of said alternating current supply at which a transition by said semiconductor power controlling means between one and the other of substantially conductive and substantially non-conductive power conditions would produce said desired amount of power;
• increasing the duration of said transition at least at said first phase angle to a sufficiently greater duration than the minimum possible said duration less than the remainder of the half-cycle to reduce the electromagnetic interference product of said transition, when said transition would not produce excessive losses in said semiconductor power controlling means, the possible impedances of the load at said output including low impedances for which there are a range of phase angles at which said transition of greater duration would cause excessive losses in said semiconductor power controlling means;
• when the impedance of the load at said output is low enough that said transition of greater duration at said first phase angle may fall within said range of phase angles, increasing the portions of a half-cycle in which said semiconductor power controlling means is in said substantially conductive power condition, relative to said desired amount of power, such that no transition is performed at a phase angle in said range.

An electronic dimming apparatus comprising:

• semiconductor power controlling means for selectively coupling a lamp load with an alternating current supply and for modulating instantaneous voltage or current, said semiconductor power controlling means having a control input;
• means for varying the amount of power supplied to said lamp load over a range of power by controlling the portions of the waveform of said alternating current supply in which said semiconductor power controlling means couples said lamp load with said alternating current supply, said varying means having:
• an output coupled with said control input,
• an input for a first value indicative of a desired amount of power to be supplied to said lamp load,
• means for determining points at which said semiconductor power controlling means should couple and decouple said lamp load from said alternating current supply in order to supply said desired amount of power,
• means, coupled with said output, for controlling said semiconductor power controlling means, at least when under load, to gradually transition between one and the other of said coupled and uncoupled conditions,
• means for relocating said transition under load from a point when the current demand of said lamp load may produce excessive losses in said semiconductor power controlling means, such that, provided that excessive losses would not be produced in said semiconductor power controlling means, an amount of power greater than said desired amount is supplied to said lamp load.

A method of operation for a dimmer, said dimmer having an input, comprising the steps of:

• coupling a semiconductor power controlling means for modulating instantaneous voltage or current between an alternating current supply and a lamp load, said semiconductor power controlling means having a control input;
• inputting a first value via said input identifying a desired amount of power for said lamp load;
• determining at least a first phase angle at which a transition by said semiconductor power controlling means between one and the other of substantially conductive and substantially non-conductive power conditions would supply said desired amount of power to said lamp load;
• changing the value at said control input of said semiconductor power controlling means to transition said semiconductor power controlling means between one and the other said power condition over a duration greater than the minimum possible duration and less than the remainder of the half-cycle to produce a progressive rate of increase in the rate of change in instantaneous voltage to said lamp load, followed by a progressive decrease in said rate of instantaneous voltage change.

A method of operation for a dimmer, said dimmer having an input, comprising the steps of:

• coupling a semiconductor power controlling means for modulating instantaneous voltage or current between an alternating current supply and a lamp load, said semiconductor power controlling means having a control input;
• inputting a first value via said input identifying a desired amount of power for said lamp load;
• determining at least a first phase angle at which a transition by said semiconductor power controlling means between one and the other of substantially conductive and a substantially non-conductive power conditions would supply said desired amount of power to said lamp load;
• changing the value at said control input of said semiconductor power controlling means to transition said semiconductor power controlling means between one and the other of said power conditions over a duration greater than the minimum possible duration and less than the remainder of the half-cycle to produce during said transition a substantially minimized second derivative of instantaneous voltage to said lamp load.