Get On Board with. Compass Card. Compass Card is the smart card and smart choice for transit passes in the San Diego region. Compass Card is your ticket for the Bus, TROLLEY, COASTER, and SPRINTER.ompass Card. Compass Card is the smart card and smart choice for transit passes in the San Diego region. Compass Card is your ticket for the Bus, TROLLEY, COASTER, and SPRINTER.
Use of Vacuum Tube Diodes Gradually p-n junction semiconductor has come in the market and vacuum tubes got replaced by them. The most basic structure of vacuum tube is vacuum diode. Still today somewhere vacuum tubes are being used widely. These fields for application of the vacuum tubes are in Atomic Clocks; Audio Systems; Car Dashboards
The purpose of a diode is to block current from flowing in one direction Diodes are typically used to protect a circuit if the power source is connected in the wrong direction. A simple diode allows current to flow through unimpeded in one direction, but completely blocks any flow in the other direction. However, there are other types of diodes, such as semiconductor diodes, that block current flow in both directions unless there is a certain amount of current.