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transistor problem, how to read datasheet

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poxkix

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Attached image included.
Okay, I have already checked the suggested thread but didn't seem to find the exact problem with transistors.

Untitled.png

Can anyone explain why the results are not the same? What is the requirement for a transistor to function? A voltage or current input to the base? I do not know how to read their datasheets. Can anyone help me?

Datasheets
2N1711
2N1711 datasheet pdf datenblatt - NXP Semiconductors - NPN medium power transistor ::: ALLDATASHEET :::

2N2222A
2N2222A datasheet pdf datenblatt - NXP Semiconductors - NPN switching transistors ::: ALLDATASHEET :::
 
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First of all you need to decide do you want to use tasisitors as ampliter of switch....

after that you need to find out which configuration that you need to use.... you need to read little more basic for both above case and then you can read the data sheet very easily..... like You can check the hfe or dc gain parametes from data sheet.... input impdeances rin etc....

may be helpful to you,

Good Luck
 

poxkix said:
Attached image included.
Click to expand...

This image shows nothing, just two transistors with grounded emitters and voltometers measuring Vce. Are there any other connections?
 

The image is what you see. I'm confused why the results are not the same? I tried reading their datasheet but I don't know where or what to compare related to the different output of the transistors.

I'm suppose to use these transistors to control the direction of a dc motor.
 

The image that you share i am afraid why the results are not the same this should be same. any how this is the logical error.
 

haree said:
The image that you share i am afraid why the results are not the same this should be same. any how this is the logical error.
Click to expand...

Oh, They should be the same? I thought it should not be the same because they are not the same. I tried to compare them using their datasheet but unfortunately I don't know what to look at to compare. So maybe someone can help me how to read those datasheets.

I used Proteus to simulate those 2 transistors.
 

poxkix said:
I used Proteus to simulate those 2 transistors.
Click to expand...

Did you change your schematic or it is still the same? You need a base resistor and a pull up resistor on the collector to have a minimal functional unit.
 

alexxx said:
Did you change your schematic or it is still the same? You need a base resistor and a pull up resistor on the collector to have a minimal functional unit.
Click to expand...

The schematic is still the same. Okay, will the resistor value matter?
 

poxkix said:
The schematic is still the same. Okay, will the resistor value matter?
Click to expand...

I think you are missing some transistor basics here.

11_1322669094.gif


Implement the above circuit (Common Emitter). Search your books, your notes, the web, datasheets, anything that you can to find out about Rb and Rc values, you must do a research of your own to gain something out of it. Keep the voltometer between Vce as it is and switch VB from 0 to 1 and observe the voltometer value. Then come back to this thread and tell us why it was wrong not to use resistors. What the effect would be if you implemented the circuit you first posted in real life?
 
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alexxx said:
I think you are missing some transistor basics here.

11_1322669094.gif


Implement the above circuit (Common Emitter). Search your books, your notes, the web, datasheets, anything that you can to find out about Rb and Rc values, you must do a research of your own to gain something out of it. Keep the voltometer between Vce as it is and switch VB from 0 to 1 and observe the voltometer value. Then come back to this thread and tell us why it was wrong not to use resistors. What the effect would be if you implemented the circuit you first posted in real life?
Click to expand...

Thank for the very solid information. I haven't really searched a lot due to classes. Unfortunately only the internet is my friend.

Okay, I tried both the transistors with your diagram and to my surprise they we're almost the same value off by just a point.
Actually I'm trying to find a transistor to work with my circuit. The transistors are supposed to be switches for the motor control.

I'll attach the circuit here. I read the datasheet it said that the Vcbo has a max value of 75v. So in my own understanding, this transistor is capable of that value. When I tried the circuit it didn't work even with just a supply of 24v to the collector. But, it will work with 12v. Where am I wrong here?
 

Q1 and Q4 are connected wrong, you should invert the drain with the source.
The sources of Q1/Q2 should be connected to the positive supply and the source of Q3/Q4 to ground.

The voltage of 24v is high for a real circuit , it will provide a Vgs of 24v and will damage the mosfets.
The max Vgs of IRF9410 is 20v

I would recommend you get familiar with transistors first before you add mosfets in your circuit.

Read a tutorial in order to understand how devices work
Tutorials, Electronics made EASY, Williamson Labs

Alex
 
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    angy

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alexan_e said:
Q1 and Q4 are connected wrong, you should invert the drain with the source.
The sources of Q1/Q2 should be connected to the positive supply and the source of Q3/Q4 to ground.

The voltage of 24v is high for a real circuit , it will provide a Vgs of 24v and will damage the mosfets.
The max Vgs of IRF9410 is 20v

I would recommend you get familiar with transistors first before you add mosfets in your circuit.

Read a tutorial in order to understand how devices work
Tutorials, Electronics made EASY, Williamson Labs

Alex
Click to expand...

I tried what you said, it doesn't work sir alexan_e. Is there other way where the source should be 24v
 

Please post your schematic.
 

alexxx said:
Please post your schematic.
Click to expand...

I'm not at home right now but it is just the same as the schematic I posted the only thing different is I swapped the connections that was said wrong
 

poxkix said:
I tried what you said, it doesn't work sir alexan_e. Is there other way where the source should be 24v
Click to expand...

Works fine for me, any idea why it didn't work for you?

Snap1.gif

In simulation it will work with 12v or 24v but in reality 24v will damage the mosfet so you need a level translator, you can use two resistors as a voltage divider.

Alex
 

Well understanding transistor datasheet is very imp for it to function properly.Link below gives a good understanding of reading datasheet

**broken link removed**

HAPPY READING!!
 

Hello all
I am confused. Did poxkix post a partial circuit showing to stupid transistors with two stupid voltmeters with 2 stupid diff. readings ?
If so we just wasted 11 posts doing nothing trying to help a stupid post. I hope i am wrong ... but if i am right why r we making such an effort to help this kind of post???????????????????????????????????
A thousand thanks for alex link http://williamson-labs.com/ i teach elevtronics and its most useeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeefull
 

Please stop judging the quality of the questions asked in the forum.
There are a lot of members new to the electronics field and may ask things which appear to be useless or stupid to someone with knowledge in electronics but that doesn't mean that we should prevent them from asking.
If you feel that a thread deals with what you consider as stupid then don't participate to that thread.

Alex
 

Right alex i didnt mean to judge.. what i ment is to advice newbies the importance of a right way of posting and lead them to that right way before hurrying answering their post it will do them only good.

---------- Post added at 12:51 ---------- Previous post was at 12:48 ----------

Right alex i didnt mean to judge.. what i ment is to advice newbies the importance of a right way of posting and lead them to that right way before hurrying answering their post it will do them only good.
liked that isis tool ill download that .


"Okay, I have already checked the suggested thread but didn't seem to find the exact problem with transistors."
and what does he mean by that ?
 
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