How to Know Vacuum Tubes
Vacuum tubes are the first steps and device that man created to harness electrical circuitry towards what gradually became known as electronics. Vacuum tubes are also called valves. Gradually semiconductor devices phased out the valves. Producers of valves did their best to miniaturized their products to the ultimate. Even at the start of space explorations and travel to moon many onboard equipment on the space ships that now are manufactured with solid-state electronics, contained circuitries built with vacuum tubes.
No one can deny the vast usage of vacuum tubes in present electronics from music amplifiers to satellites and earth radio stations. When you need power together with efficiency, then you need vacuum tubes, or electron valves.
Steps
- Note that each electron valve needs a circuitry to make the device warm and ready. This is called heater or filament element.
- Know what is a diode valve. Job of a diode valve is to rectify an alternating current. In this role it acts like a water tap that can be opened for, say, positive current and close for negative current; hence a valve. In modern electronics it is substituted with a semiconductor diode. It has three parts.
- Heater
- Cathode
- Anode
- It is set inside a glass tube which is vacuumed of air; hence is called a vacuum tube. Semiconductor equivalent of diode is a solid state diode.
- Know that the physical production of a vacuum tube is manufactured in standard forms to be usable and ubiquitous. For example though a vacuum diode needs only four connection its socket comes as the so-called 'octal' with eight connectors; few of the connections are NC: No Connect.
- This also makes it to integrate two diode structure inside one physical diode, called "double diode" or 'duo'-diode.
- See how a diode valve is used to rectify an alternating voltage source into a dc 425 volts voltage source to be used in a vacuum tube circuit.
- Additionally the transformer provides a 6.3 volts (to create heat it is not necessary to convert this into a dc voltage) to be used and feed the heaters of all the valves in the circuit.
- Learn about the triodes. Triodes add a control to the diode that is a new electrode is introduced into the diode to make it possible to control the amount of current, the number of electrons that travel from the cathode to the anode. Semiconductor equivalent of triode is a transistor.
- Learn about the tetrodes. This vacuum tube has an extra grid known as the screen grid. Screen grid is added between control grid (i.e., the one that in a triod is called just a grid)and anode. This improvces the stability of gain.