TRANSISTOR SELECTION QUESTION

[magnetman12003]

I am making a project that requires a single NPN transistor. Wish to power the transistor with 12 volts without using a large resistor connected to its base.

What transistor can have a ""BASE"" voltage of ""!2 volts"" applied ''DIRECTLY'' to its base without burning up the transistor?  In most cases there is some large value of resistor there.  Transistor would have to be a motor switching type.  The faster the better.   Need part numbers.

[citfta]

Hi magnetman12003,

I have seen several posts by you on this and other forums where you are asking questions that indicate you don't really have a good understanding about electronics.   I would like to respectfully suggest that you take the time to study some of the free online electronics classes.  If you are serious about working or experimenting in this hobby then a good understanding is a must.  You will only frustrate yourself trying to make things work when you don't understand what you are doing.

For instance to answer your own question in this thread you can go online and look for info about the different types of transistors.  I am pretty sure you will find there are NO npn transistors you can apply 12 volts to the base and not burn out the transistor.  However there are other types like Mosfets that can take 12 volts to the gate.  Do you even know why the resistor is going to the base?  And why do you think you need to remove it?

Respectfully,
Carroll

[magnetman12003]

Hi magnetman12003,

I have seen several posts by you on this and other forums where you are asking questions that indicate you don't really have a good understanding about electronics.   I would like to respectfully suggest that you take the time to study some of the free online electronics classes.  If you are serious about working or experimenting in this hobby then a good understanding is a must.  You will only frustrate yourself trying to make things work when you don't understand what you are doing.

For instance to answer your own question in this thread you can go online and look for info about the different types of transistors.  I am pretty sure you will find there are NO npn transistors you can apply 12 volts to the base and not burn out the transistor.  However there are other types like Mosfets that can take 12 volts to the gate.  Do you even know why the resistor is going to the base?  And why do you think you need to remove it?

Respectfully,
Carroll

Do you think a FJP5554 transistor available from Mouser can be used without a resistor in the base circuit.
The VEBO is 15 volts?

[magnetman12003]

Hi magnetman12003,

I have seen several posts by you on this and other forums where you are asking questions that indicate you don't really have a good understanding about electronics.   I would like to respectfully suggest that you take the time to study some of the free online electronics classes.  If you are serious about working or experimenting in this hobby then a good understanding is a must.  You will only frustrate yourself trying to make things work when you don't understand what you are doing.

For instance to answer your own question in this thread you can go online and look for info about the different types of transistors.  I am pretty sure you will find there are NO npn transistors you can apply 12 volts to the base and not burn out the transistor.  However there are other types like Mosfets that can take 12 volts to the gate.  Do you even know why the resistor is going to the base?  And why do you think you need to remove it?

Respectfully,
Carroll

I have already made a self sustaining setup that charges a single 12 volt battery powering it.  My problem is I don't have quite enough current to fully  charge my single 12 volt 1.2 AH battery. Thus only a 5 straight hour run time.  That's why the questions about any current robbing resistor connected to the base of the transistor.  I am not well trained in transistor selection but can put any circuit diagram together very quickly.  My hope is to find a very simple Tesla  pancake type circuit that is very efficient as far as current flow and build it in hopes I can boost the current.  With that accomplished I will have at least a self sustaining runner with the run battery being charged at the same time.

[pomodoro]

The base resistor, uses practically no power if you make it large enough.  Look for darlington NPN  power transistors to make it even less of an issue.  MOSFETS and IGBT are best avoided as they have a large capacitance which uses up some current. A TIP122 is a popular generic one one I use, 100V, 5A (8A Peak),current gain of 1000  beware of the the built in diode, it may not suit your needs. There are plenty of others which may be better for your design I don't know what your circuit is like.