Patent ID: 8493055

Claim:
A voltage measurement apparatus for measuring an output voltage from a power supply, to determine whether the output voltage can be as a work voltage, the work voltage comprising an upper limit and a lower limit, wherein the upper limit is greater than the lower limit, the voltage measurement apparatus comprising: a power interface to be connected to the power supply; a first voltage detecting module to receive the output voltage from the power supply through the power interface and compare the output voltage with a first reference voltage proportional to the upper limit voltage, to determine whether the output voltage is greater than the first reference voltage, to further determine whether the output voltage is greater than the upper limit voltage; a second voltage detecting module to receive the output voltage and compare the output voltage with a second reference voltage proportional to the lower limit voltage, to determine whether the output voltage is less than the second reference voltage, to further determine whether the output voltage is less than the lower limit voltage; a first indication module; a first driving module to drive the first indication module to indicate the output voltage when the output voltage is greater than the upper limit voltage; a second driving module to drive the first indication module to indicate the output voltage when the output voltage is less than the lower limit voltage; and a second indication module to indicate the output voltage driven by the first and the second driving module when the output voltage is less than or equal to the upper limit voltage and greater than or equal to the lower limit voltage.