ABSTRACT
The transmissive switch consists of a light source, receiver, a means of interrupting the flow of the light beam, and a means of fixing these in a mechanical configuration that allows repeatability of the function. “Transmissive” housings are typically used in applications where dusty or other particulate environments. Different types of housing material offer unique application configurations. Some switches are available with a base-mounting fixture for the housing, resulting in a device that is “open” to the environment. A slotted switch is made with either a transmissive or opaque housing. Slotted switches are a single channel with one emitter and one photosensor and can be used in many switching applications. The digital sequence expected from each configuration is dependent on the position of the apertures of the device in reference to the slots in the encoder wheel. Flag switches are a special type of slotted switch in which the target that breaks the energy beam is preassembled on the assembly.
