Differences between a triode and a diode?

Answer 1

A triode refers to a vacuum tube amplifier or switch of the simplest form. It has three parts: A heated cathode, a control grid and an collection plate anode.

Electrons are emitted from the cathode and drawn towards the positive anode. Interposed between the two is a control grid that controls the cathode-to-anode electron flow by being charged appropriately, for example a negative charge (ground) on the grid will hamper the flow since the negative electron charge on the grid will obstruct the electron flow to the positive anode.

There are a number of variations in electronic tube designs. Even though tubes have been supplanted by solid state designs generally, they still have many valuable uses.

A transistor is a solid state device made of "P" and "N" type materials so arranged as to modify the current through it to amplify or switch current flow.

There are also many types of solid state transistor designs and they are now far more common than electron tubes.

the difference one is a voltage amplifier and the other is a current amplfier that is the major difference.

Further important differences:

Vacuum-tube triodes need some hundreds of milliwatts to watts just to light the filament/heater. This is wasted power that can appear as waste heat in the circuit, and reduces the electrical efficiency of the vacuum-tube triode. Triodes also have limited lifetimes, commonly due to the filament/heater burning out, or losing its electron emission. Transistors have no such limitations and are (i) much more efficient, (ii) can run at much lower power, and (iii) have very long lifetimes.

Vaccuum-tube triodes cannot be made much smaller than around 10 mm/half an inch in diameter, and maybe the same length. Transistors can be made at the nanometre scale, so transistor electronics are much more compact. Imagine putting together a USB memory chip with (at least) 32,000,000,000 triodes!

Conventional triodes are able to operate to about 5 GHz (5000 MHz). Some special valves can work at higher frequencies, about around 100 GHz is the limit. Such valves are large, expensive, and have high noise figures. Low-noise, small, cheap transistors exist that can easily work past 100 HGz.

Answer 2

One big difference is that Transistor consist of three layers pnp or npn, while thyristor hove four layers pnpn.

As far as functioning is concern, in transistor whenever gate voltage is above threshold transistor is in on state. when you remove gate current transistor turns off. In case of thyristor, when you supply gate current, it is triggered and start conducting. Now even if you remove gate current it will be in on state. Thyristor will turnoff if the voltage across it falls threshold level. Thus unlike transistor in thyristor we don't have to supply regular gate current, instead we just need to trigger it by gate current than it will conduct on it's own

Answer 3

Triode is an obsolete form of a Transistor.

A Diode has two terminals and enable current to be flowed only in one direction. So its a current flow direction regulator.

A Triode has three terminals, anode, cathode and grid. As a transistor, a triode was used as an amplifier of current. The current will flow from the anode to the cathode. The voltage applied to the grid will control the amount of current that will flow, and thus, it regulates the level of amplification.

Clarification. The above confuses thermionic valves and transistors.

First, triode IS NOT an obsolete form of transistor, because...

A triode is an electronic device with three electrodes: current input, control and current output.

In a thermionic valve (vacuum tube) the electrodes are cathode, grid and anode.

In a biploar junction transistor (what most people mean by "transistor"), the elctrodes are emitter, base and collector.

In a field-effect transistor (JFET, MOSFET, IGFET), the electrodes are source, gate and drain.

Answer 4

A transistor can act as an amplifier. An amplifier you use for music might have many transistors as well as many other types of components. Transistors have other applications as well.

Answer 5

A diode has one semi-conductor junction and a transistor has two.

Answer 6

Difference between transistor and amplifier

Answer 7

grid