One popular device that uses a Hall IC is a flow meter (Figure 15). The spoked wheel (paddle wheel), is driven by some type of medium flowing through the pipe. A magnet is attached at the tip of each spoke. In the presence of moving vapor or liquid, the magnets spin at a speed related to the viscosity of the medium flowing through the device. The spinning magnets will switch the Hall IC, producing a square wave output, with a frequency proportional to the flow rate.
Liquid or vapor entering in the direction of the arrow spins the paddle wheel switching the Hall IC “ON” and “OFF”, creating a square wave output. Power Control Many switches must control significant power. A Hall IC can do this only through a relay or Power FET. |