Multi-way output LED constant-current driving circuit and driving method

Abstract

The invention discloses a multi-way output LED constant-current driving circuit which comprises a power supply dimming module, a reverse activation control module, a current feedback module, a transformer, an output detection module and at least two LED load access channels. The invention further discloses a multi-way output LED constant-current driving method which is applied to the multi-way output LED constant-current driving circuit. The invention relates to the technical field of LED driving. By adopting the multi-way output LED constant-current driving circuit and the driving method, the reverse activation control module is combined with the power supply dimming module, the current feedback module, the output detection module and the transformer, constant driving current is output according to the number of LED lamps accessed through the LED load access channel and different dimming requirements, the operation is stable, and compared with the prior art of a constant-voltage driving power supply, the driving circuit needs no secondary constant current treatment and is low in cost. Tangent phase signals of the power supply dimming module are sampled in real time through the current control module, different current adjustment dimming ranges are output according to a tangent phase dimmer, and the purposes of low dimming depths and wide dimming ranges are achieved.

Description

technical field [0001] The invention relates to the technical field of LED driving, in particular to a multi-channel output LED constant current driving circuit and a driving method. Background technique [0002] At present, LED is called the fourth-generation lighting source or green light source. It has the characteristics of energy saving, environmental protection, long life, and small size. It has been widely used in various indications, displays, decorations, backlights, general lighting and urban night scenes. . The driving power applied to the LED backlight usually has multiple outputs, but the existing multi-output LED driving devices have the following defects: [0003] (1) Since the luminous intensity of the LED is determined by the current flowing through the LED, a stable luminous intensity requires a constant current drive, and the drive of multiple LED loads needs to control the current of each LED load to be constant. The existing multi-channel Most of the L...

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Problems solved by technology

[0003] (1) Since the luminous intensity of the LED is determined by the current flowing through the LED, a stable luminous intensity requires a constant current drive, and the drive of multiple LED loads needs to control the current of each LED load to be constant. The existing multi-channel Most of the LED constant current drive schemes adopt a one-to-one drive mode, that is, one LED load corresponds to one constant current drive circuit. If you want to output different current parameters, you can only change the parameters of the power supply, or replace other drive power supplies. and inconvenient

[0004] (2) The existing multi-channel output driving power is mostly constant voltage output driving power, and LED is used as a constant current light source. When the LED needs multiple outputs, if the constant voltage output driving power is used, it is necessary to do two Level constant current processing, low efficiency, high cost, and constant voltage output driving power supply is difficult to dim, and the linearity is poor, which cannot meet the dimming needs of the market

[0005] (3) In the prior art, the multi-channel output power supply is multi-channel output at the same time. For the user, it is impossible to effectively select the output. The multi-channel output power supply often only effectively applies one or two sets of outputs. In the case of low standby power consumption, it will inevitably cause waste of resources

[0006] (4) In the prior art, the dimming signal detection of LED drive power is mostly amplitude detection, which is greatly affected by the fluctuation of mains power, has poor reliability, high dimming depth, and narrow dimming range

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