A BJT is one type of transistor and POWER TRANSISTOR can be BJT or MOSFET or some other phenomena.POWER TRANSISTOR are usually those who are used at high current ratings e.g at POWER AMPLIFIER where large transistors are used at final stage to gain output.
A power transistor is physically larger, and capable of carrying more current without melting or burning up. Usually a power transistor has a heatsink attached to help remove heat from the device and keep it cool.
A Mosfet is a (spelled down):
Metal
Oxide
Semiconductor
Field
Effect
Transistor
A power transistor could be a power mosfet, but a power mosfet is not the only option for power transistor - you could use a BJT, JFET, etc.
A JFET is the basic type of FET. In an ordinary transistor, the junction between the base and the collector is essentially a reverse biased diode. However when charge carriers (electrons or holes) are injected by the emitter, the diode conducts.
In a JFET, a piece of doped semiconductor material is allowed to conduct from one end (the source) to the other (the drain). An insulated electrode is placed VERY close to the semiconductor material, so that voltages on that electrode can push the holes or electrons away capacitively, thus narrowing the conductive channel, and raising it's resistance.
There are P channel and N channel JFETs, intended to operate on positive or negative supply coltages.
MOSFET is a voltage controlled device and BJT is a current controlled device. MOSFEThas three terminals as gate, source and drain. BJT has three terminals as base, coolector and emitter.
ITS AN NPN TRANSISTOR , GENERALLY USE AS A SWITCH GENREALLY IN COMMON EMITTER CONFIGURATON
Power FET
NPN and PNP transistors function in essentially the same way. The power supply polarities are simply reversed for each type. The only major difference between the two types is that the NPN transistor has a higher frequency response than the PNP-because electron flow is faster than hole flow. Therefore high frequency applications will utilize NPN transistors.
An AS162 transistor is a type of PNP transistor commonly made of germanium. This is an older kind of transistor that was often found in power amplification circuits.
a 603 12F high current power, multi-emitter transistor.
Power transistor can conduct large amount of currents through it, more than small signal transistor. power transistor has a vertical structure and small signal transistor has horizontal structure.In power transistor quasi saturation region is present which is absent in the small signal transistor. In power transistor there is a inculsion of drift layer which is not there in the small signal transistor. Power dissipation is less in power transistor and it is more in small signal transistor. b.v.polytechnic,vasai pushkar vaity.
mosfet base power inverter of advantages and disaadvantages
ITS AN NPN TRANSISTOR , GENERALLY USE AS A SWITCH GENREALLY IN COMMON EMITTER CONFIGURATON
1-BJT is bipolar while JFET is unipolar. 2-BJT has low input impedence while JFET has high input impedence. 3-JFET has low power discipation as compared to BJT. 4-JFET has low noise as compared to BJT. 5-BJT is current controlled while JFET is voltage controlled. 6-JFET is mostly used in digital circuits.
So as opposed to a BJT transistor (which has a large but measurable input impedance) a Mosfet has even larger (presumably infinite) impedance. The reason is because of a small non-conducting zone that exists between the Gate side and the Drain-Source side. It acts as a small capacitor (which capacitors have infinite resistance), and the electromagnet field produced is what drives current between Source and Drain. Now, why is this desirable? In the case of BJT's there is a small current that flows into the base, essentially drawing small but existent power from the circuit connected at the Base. It is more ideal to have a transistor that completely separates the current of the control circuit and the current in the circuit being switched/supplied. Simply, it means its more efficient. When BJT transistors are turned off, power is still being used. The same isn't necessarily true for Mosfet transistors.
Use a mosfet driver instead of a simple resistor. Using a resistor to control the mosfet is a bad idea anyways because you will have terrible control (mosfets are voltage controlled. Take a look at the response curve for your mosfet). If your mosfet is fully on, its ratings may be too low for continuous operation or the power dissipation is too low for the transition between off an on an that is killing your mosfet.
Power FET
A Power MOSFET is a voltage controlled device http://www.profesores.frc.utn.edu.ar/industrial/sistemasinteligentes/UT1/Understandig%20Pwr%20Mosfets.PDF
By choosing the type of transistor to meet your needs carefully. I assume what you're trying to do is feed beyond the ttl output's power capability? a JFET may be a good option. A simple amplifier circuit using a MOSFET may be all you need, and this might be more readily available.
A transistor is a device used to switch power between electrical components. Transistors work to amplify existing signals as well as open and close circuits.
Photo transistor always work with solar power
NPN and PNP transistors function in essentially the same way. The power supply polarities are simply reversed for each type. The only major difference between the two types is that the NPN transistor has a higher frequency response than the PNP-because electron flow is faster than hole flow. Therefore high frequency applications will utilize NPN transistors.