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
A TYPICAL VACUUM FORMER. Vacuum forming is a technique that is used to shape a variety of plastics. In school it is used to form/shape thin plastic, usually plastics such as; polythene and perspex. Vacuum forming is used when an unusual shape like a dish or a box-like shape is needed.