The role of voltage sensors
Function of voltage sensor: A voltage sensor is a sensor that can sense the measured voltage and convert it into a usable output signal. In various automatic detection and control systems, it is often necessary to track and collect high-speed changing AC and DC voltage signals, and perform spectrum analysis on more complex voltage waveforms. This type of signal may be a high voltage, high current and other strong current, or it may be a weak current with a poor load capacity or a small amplitude signal. In these cases, it is necessary to use a suitable voltage sensor to collect voltage signals that cannot be directly measured or do not match, so as to obtain standardized, electrically isolated voltage signals.
For AC voltage measurement, a voltage transformer can be used as a sensing element, that is, a voltage transformer is used to reduce the measured voltage to a usable low voltage, and then converted into a DC voltage that has a linear relationship with the measured voltage through related circuits. Send to the data acquisition system and A / D converter.
When the measured voltage is a DC voltage, a voltage-dividing resistor can be used as a sensing element, and the resistance value connected in parallel at both ends of the measured element should be sufficiently large (generally it should be controlled to consume less than 1/1000 of the rated power of the measured motor) In order to reduce the influence of the loss caused by the loop current on the measured value as much as possible, for low-voltage motors, it should be about 10KΩ. Take a part of the voltage drop of the measured voltage on the resistance as a signal and directly send it to the data acquisition system and A / D converter.
