Patent attributes
A fluid flow sensor, a method of detecting flow/no flow and flow systems employing same are provided. In one embodiment, an infrared light emitting diode (“LED”), phototransistor, rigid housing and a flexible opaque diaphragm are used. The diaphragm opens upon a certain pressure and closes when that pressure is no longer present. The infrared LED is located at one end of a flow sensor, while the phototransistor is located at the opposite end. The flexible opaque diaphragm is located between the LED and the phototransistor. When flow is initiated, the diaphragm is pushed open allowing light from the infrared LED to pass through and be detected by the phototransistor. When flow is stopped, the diaphragm returns to the closed position and light no longer is allowed to pass through and therefore is not detected by the phototransistor.
