Lamp drive under voltage alarm circuit

Abstract

A lamp drive under voltage alarm circuit is used for giving an alarm signal in the case of under voltage of lamp drive power supply voltage. The circuit comprises a voltage conversion module used for converting input voltage into rated voltage, a voltage comparison module, a switch module and an alarm module, wherein the input end of the voltage conversion module inputs power supply voltage; the output end of the voltage conversion module is electrically connected with the input end of the alarm module; the positive phase input end of the voltage comparison module inputs reference voltage, the negative phase input end of the voltage comparison module inputs power supply voltage, and the output end of the voltage comparison module is electrically connected with the control end of the switch module; the input end of the switch module is electrically connected with the output end of the alarm module, and the output end of the switch module is grounded. When the power supply voltage is lower than the reference voltage, the voltage comparison module outputs high level, the switch module receives the high level to be conducted, the alarm module forms a communication loop via the switch module, the alarm module gives an alarm signal to remind the user that the power supply voltage at the moment is in the under voltage state.

Description

technical field

[0001] The invention relates to an undervoltage alarm circuit, in particular to a simple lamp driving undervoltage alarm circuit. Background technique

[0002] Undervoltage refers to the phenomenon that the line voltage will be greatly reduced or even disappeared in a short period of time due to short-circuit faults and other reasons. It can cause damage to wiring and electrical equipment. For example: the motor is fatigued and blocked, resulting in an overcurrent several times the rated current and burning the motor; when the voltage is restored, the self-starting of a large number of motors will greatly reduce the voltage of the motor, causing harm.

[0003] Similarly, when the power supply voltage is undervoltage, it will cause the power supply current to increase and thus damage the drive of the power supply. Therefore, due to the inaccurate positioning of most circuits due to undervoltage, there is no humanized warning, which makes it very inconvenient...

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