Adjustable high-low voltage alarm device

The utility model relates to an adjustable high-low voltage alarm device, which comprises a detection voltage input module, a high-low voltage synchronous detection module, a direct current power supply module and a sound-light alarm module. The high-low voltage synchronous detection module is composed of a high-voltage piezoresistor, a low-voltage piezoresistor and a voltage comparator; the sound-light alarm module is composed of a light emitting diode, a relay and a buzzer. The voltage comparator is bridged between an external power supply and electric equipment, and when the voltage of theexternal power supply is too high or too low, the voltage of the positive and negative input ends of the voltage comparator changes. A voltage comparator in the high-low voltage synchronous detectionmodule generates reverse rotation, the output end outputs current, and a signal indicator lamp in the sound-light alarm module works; and meanwhile, the light emitting diode is conducted with the relay to attract, and the buzz