A self-adaptive zero-cross protection relay for lighting control

Abstract

The invention relates to an adaptive zero-crossing protection relay for light control, which includes a live wire sampling circuit, a relay feedback sampling circuit, a relay drive circuit and a micro-processing unit; the live wire sampling circuit samples the phase of the alternating current in real time, and The sampling result is sent to the micro processing unit; the relay feedback sampling circuit samples the contact state of the relay in real time to obtain accurate closing and disconnecting moments, and the sampling result is sent to the micro processing unit; the relay The drive circuit amplifies the control signal from the micro-processing unit to drive the main relay as a switching element to act; the micro-processing unit obtains the zero-crossing trigger time according to the set program according to the sampling information of the live wire sampling circuit and the relay feedback sampling circuit . Therefore, the triggering time can be adjusted according to the actual action performance of the relay used in the relay light control circuit, and the self-adaptive function is achieved.

Description

technical field [0001] The invention relates to a lighting control circuit, in particular to an adaptive zero-crossing protection relay for lighting control. Background technique [0002] There are usually two types of switching elements in the controller in the lighting room, one is through a simple control relay, and the other is to control the thyristor to realize the lighting function, both of which have their own advantages and disadvantages. The advantage of using a relay as a switching element is that the contact capacity is large and the cost is low. The disadvantage is that due to the existence of mechanical contacts, frequent live closing and disconnection, long-term use is prone to contact erosion, and the relay contacts cannot be effectively protected, resulting in The user can not effectively control it in actual use, which causes user troubles; the advantage of using a thyristor as a switching element is that there is no mechanical contact, and there will be no...

AI Technical Summary

Problems solved by technology

However, because the zero-crossing trigger time of the existing relay lighting control circuit is fixed and cannot be adjusted, and the operating performance of relays of different specifications is not the same, even for relays of the same specification, the operating performance cannot be guaranteed due to the production process. They are exactly the same, so they cannot be replaced with each other; and even the original relays at the time of production, after a period of use, their operating performance will change, and the existing circuit cannot automatically adjust the zero-crossing trigger time according to the changes. As a result, the effect of zero-crossing control gradually decreases, shortening the service life

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