Triac drive for lighting and for inductive load control
First Claim
1. A dimmer for controlling the power delivered to a load from a source of line voltage and alternating current, comprising a triac having an input terminal, output terminal and a gate, the triac being responsive to triggering gate currents applied at selectable phase angles during each half cycle of the alternating current to deliver selectable amounts, corresponding to the phase angle at which the triggering gate current is applied, of proportional power to the load, the dimmer including a circuit which regulates the duration during which the triggering gate current is applied to the triac, said circuit being capable of applying triggering gate currents of different durations to said triac.
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Accused Products
Abstract
A dimmer for use in lighting control in which a triac control circuit in included which allows for control of both incandescent and low voltage lighting systems at low and high intensities 142,144. The triac control circuit includes a microcontroller 130 which alters the duration of the gate triggering pulse for the triac 134 based upon the desired intensity level of the load. This dimmer is used in a lighting control system and the dimmer is responsive to a system controller 2 as well as to momentary switch inputs which are made directly to the dimmer. The triac control circuit can also be used with other inductive loads.
36 Citations
21 Claims
- 1. A dimmer for controlling the power delivered to a load from a source of line voltage and alternating current, comprising a triac having an input terminal, output terminal and a gate, the triac being responsive to triggering gate currents applied at selectable phase angles during each half cycle of the alternating current to deliver selectable amounts, corresponding to the phase angle at which the triggering gate current is applied, of proportional power to the load, the dimmer including a circuit which regulates the duration during which the triggering gate current is applied to the triac, said circuit being capable of applying triggering gate currents of different durations to said triac.
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11. A dimmer for use in controlling AC electrical power received from a supply and delivered to a fixture comprising:
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a zero crossing detector to determine the time when AC line voltage from the supply is zero; a microcontroller in the dimmer configured to output a gate control signal corresponding to the intensity level to which the fixture is to be dimmed, the zero crossing detector being connected as an input on the microcontroller; a triac in the dimmer activated by the gate control signal output from the microcontroller as a function of the zero crossing time of the AC line voltage, so that the power delivered by the dimmer to the load corresponds to the intensity level to which the fixture is to be set; and input means to the microcontroller at which first control signals characteristic of the intensity level to which the fixture is to be dimmed and second control, signals for changing the operational mode of the microcontroller are received, the microcontroller controlling the triac so that the dimmer changes the intensity level of the fixture in a different manner in response to identical first control signals for different operational modes. - View Dependent Claims (12, 13, 14, 15)
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16. A system for controlling the delivery of AC electrical power to fixtures, the system comprising:
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a system controller; a plurality of branches, each branch including AC electrical power conductors and signal conductors, the system controller transmitting control signals on the signal conductors; a dimmer block on at least one branch, the AC electrical power conductors and the signal conductors on the branch being connected to the dimmer block;
the dimmer block further comprising a branch interface to which the signal conductors transmit input signals from the system controller adapted to cause the power to be delivered to a fixture attached to the dimmer block in a first pattern, and a triac, both the branch interface and the triac being connected to a microcontroller, the microcontroller conditioning the signals received by the branch interface into gate control signals for activating the triac so that the power is delivered to the fixture different from the first pattern, the final power delivery state of the fixture being the same for both the first pattern and the second pattern. - View Dependent Claims (17, 18, 19, 20)
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21. A dimmer for controlling the power delivered to an inductive load from a source of line voltage and alternating current, comprising a triac having an input terminal, output terminal and a gate, the triac being responsive to triggering gate currents applied at selectable phase angles during each half cycle of the alternating current to deliver selectable amounts, corresponding to the phase angle at which the triggering gate current is applied, of "proportional power" to the load, the dimmer including means for generating a first triggering gate current having a first duration to be applied to the gate of the triac for power levels to be applied to the load in a first range and for generating a second triggering gate current, having a second duration longer than the first duration of the first triggering gate current, to be applied to the gate of the triac for power levels to be applied to the load in a second range, exceeding the power levels in the first range.
Specification