Integral half cycle (IHC) control
AssigneeHewlett-Packard Development Company, L.P.
InventorMark Hirst
Life of this patent
Estimating the term…
Abstract
Power to an electrical device is controlled using a phase control that changes a cutoff phase of an alternating current (AC) electrical signal delivered to the electrical device. The power delivered to the electrical device is increased to an operational level using the phase control. A level of the power delivered to the electrical device is maintained at the operational level using an integral half cycle control that selectively removes a plurality of half cycles from the AC electrical signal delivered to the electrical device such that a plurality of remaining half cycles in the AC electrical signal delivered to the electrical device have a frequency outside a range of sub-harmonic frequencies.
Claims17
A method comprising:
- controlling power to an electrical device using a phase control that changes a cutoff phase of an alternating current (AC) electrical signal delivered to the electrical device;
- increasing the power delivered to the electrical device to an operational level using the phase control;
- and
- maintaining a level of the power delivered to the electrical device at the operational level using just an integral half cycle control that selectively removes a plurality of half cycles from the AC electrical signal delivered to the electrical device such that a plurality of remaining half cycles in the AC electrical signal delivered to the electrical device have a frequency outside a range of sub-harmonic frequencies,
- wherein selectively removing the half cycles from the AC signal delivered to the electrical device using just the integral half cycle control such that the frequency of the remaining half cycles in the AC electrical signal is outside the range of sub-harmonic frequencies reduces perceptible flicker caused by the AC electrical signal.
A non-transitory computer-readable data storage medium storing program code executable by a processor to perform processing comprising:
- controlling power delivered to an electrical device using a phase control that changes a cutoff phase of an alternating current (AC) electrical signal;
- increasing the power delivered to the electrical device to an operational level using the phase control;
- and
- maintaining a level of the power delivered to the electrical device at the operational level using just an integral half cycle control that selectively removes a plurality of half cycles from the AC electrical signal delivered to the electrical device such that a plurality of remaining half cycles in the AC electrical signal delivered to the electrical device have a frequency outside a range of sub-harmonic frequencies,
- wherein selectively removing the half cycles from the AC signal delivered to the electrical device using just the integral half cycle control such that the frequency of the remaining half cycles in the AC electrical signal is outside the range of sub-harmonic frequencies reduces perceptible flicker caused by the AC electrical signal.
A system comprising:
- a triac device to control delivered to an electrical device using a phase control that changes cutoff phase of an alternating current (AC) electrical signal, and to increase a power delivered to the electrical device to an operational level using the phase control;
- and
- a controller to maintain a level of the power delivered to the electrical device at the operational level using just an integral half cycle control that selectively removes a plurality of half cycles from the AC electrical signal delivered to the electrical device such that a plurality of remaining half cycles in the AC electrical signal delivered to the electrical device have a frequency outside a range of sub-harmonic frequencies,
- wherein selectively removing the half cycles from the AC electrical signal delivered to the electrical device using just the integral half cycle control such that the frequency of the remaining half cycles in the AC electrical signal is outside the range of sub-harmonic frequencies reduces perceptible flicker caused by the AC electrical signal.
Dependencies are inferred from the claim text.