Triac switch detecting circuit

Abstract

The invention discloses a Triac switch detecting circuit. The circuit is characterized by comprising a rectifier bridge, a light emitting diode group, a Triac switch holding current path and an LED current control circuit; the rectifier bridge is connected with a positive pole of the light emitting diode group; the positive pole of the light emitting diode group is connected with the Triac switchholding current path, and a negative pole of the light emitting diode group is connected with the LED current control circuit; an output end of the LED current control circuit is connected with the Triac switch holding current path, the Triac switch holding current path is connected with the rectifier bridge; and the Triac switch detecting circuit further comprises a TRIAC detection circuit and apulse width detection circuit. The Triac switch detecting circuit in the invention solves the problem whether a lamp is connected to the Triac switch, and according to the detection result, the holding current of the Triac switch is opened and closed, thereby improving the efficiency of linear Triac LED driving.

Description

technical field [0001] The invention relates to the field of LED drive circuits, in particular to a Triac switch detection circuit. Background technique [0002] Triac switch is the standard configuration of household lamps, but the new LED lamps are not well adapted, and complex drive circuits are required. In the early days, switching power supplies were used to achieve high driving costs; later, a linear Triac switch was developed. Optical drive, by increasing the loss to achieve the purpose of adapting to the Triac switch, which makes it difficult for the efficiency to exceed 75%; the US Energy Star standard clearly requires that the efficiency of lighting products must be greater than 80%, and the test environment It is not connected to the Triac switch, and it is difficult to meet the above requirements with traditional linear Triac dimming products. [0003] Such as figure 1 It is a traditional linear Triac LED drive circuit, which includes a rectifier bridge, a lig...

AI Technical Summary

Problems solved by technology

[0005] When there is a Triac switch in the driving circuit of the lamp, there is a circuit to maintain the normal operation of the Triac switch, and the maintenance circuit has a certain loss; because the existing lamps cannot detect whether there is a Triac switch in the circuit, the maintenance circuit will always be turned on, causing unnecessary loss, resulting in low efficiency of lamps; so the design of the Triac switch detection circuit becomes particularly important

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