depression definition. A period of drastic decline in the national economy, characterized by decreasing business activity, falling prices, and unemployment. The best known of such periods is the Great Depression, which occurred in the 1930s.
A variometer â also known as a rate of climb and descent indicator (RCDI), rate-of-climb indicator, vertical speed indicator (VSI), or vertical velocity indicator (VVI) â is one of the flight instruments in an aircraft used to inform the pilot of the rate of descent or climb.
These two methods include zero speed switches and differential air pressure switches. Zero Speed Switches A zero speed switch is a device used to detect the presence of rotation in a shaft. In LEWCOâs application it is the shaft on which the fan wheel or impeller is mounted. The switch consists of a circuit card and a magnet assembly.