Wheatstone Bridge Structure and Balance
One of the core components of a pressure sensor is the Wheatstone bridge, typically composed of four resistors forming a closed loop. When the external pressure is zero, the bridge is in equilibrium, and the output voltage is zero. This design is analogous to the initial state of a balance scale, where the weights on both sides are equal, and the pointer points to the middle.
How Pressure Changes Disrupt the Balance
When external pressure acts on the sensor, the resistance of the sensing element changes. This is like adding a weight to one side of the balance scale, causing the bridge to lose its balance. The change in resistance is proportional to the pressure, resulting in a small voltage difference. This voltage difference is the sensor's output signal.
Output Signal Processing and Application
The small signal output by the bridge needs to be amplified and filtered before it can be recognized and used by subsequent circuits. This design not only improves measurement sensitivity but also effectively suppresses environmental interference. In practical applications, bridge-type pressure sensors are widely used in industrial control, medical equipment, and other fields due to their stability and reliability.
