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
Vacuum Diode History Working Principle and Types of Vacuum Diode. History of Vacuum Diode. In November 16, 1904 first vacuum diode was invented by Sir John Ambrose Fleming and it is also called the Fleming valve, the first thermionic valve. In those days there was no existence of p-n junction in electronics field. A conceptual figure of vacuum diode is shown below. How does vacuum tube diode work? Here the vacuum diode works mostly like modern diode. But its size is larger. It consists of a vacuum container with cathode and anode inside. This cathode and anode are connected across a voltage source. The anode is applied with positive voltage with respect to cathode.