Please,forgive me for my bad english.
I'm from Serbia.
Healp me:
My problem is it:
How matching two pars transistors 2N3055 in audio amplifier.
I know this possible with matching transistors,their gain Hfe,but if gain is not homologous (seem) ,uses emitors resistors examp.0,1-0,47 oms.
It is true?
Which size of oms is ok for this.
Why is uses milioms resistors in emitor of transistors(output transistors)?
Please see my shematics and your comomment?
ps: T6,T7 is 2N3055,T4/T5 drivers BC286/287,R16,R17 0,47 oms.
I'm from Serbia.
Healp me:
My problem is it:
How matching two pars transistors 2N3055 in audio amplifier.
I know this possible with matching transistors,their gain Hfe,but if gain is not homologous (seem) ,uses emitors resistors examp.0,1-0,47 oms.
It is true?
Which size of oms is ok for this.
Why is uses milioms resistors in emitor of transistors(output transistors)?
Please see my shematics and your comomment?
ps: T6,T7 is 2N3055,T4/T5 drivers BC286/287,R16,R17 0,47 oms.
Attachments
I this design I can't imagine that you'll need to match the output transistors.
Emitter resistors are usually in the range you describe and this for creating a voltage drop of 0.3 1.0 V. This voltage is used for controlling the working conditions of the transistor especially when it gets hot. If you don't have these resistors the transistor will draw more current -> hotter -> even more current -> even more hot -> more more -> -> -> -> -> ->
Emitter resistors are usually in the range you describe and this for creating a voltage drop of 0.3 1.0 V. This voltage is used for controlling the working conditions of the transistor especially when it gets hot. If you don't have these resistors the transistor will draw more current -> hotter -> even more current -> even more hot -> more more -> -> -> -> -> ->
For a test circuit to match dc current gain of transistors, look here:
http://users.ece.gatech.edu/~mleach/lowtim/part2.html
http://users.ece.gatech.edu/~mleach/lowtim/part2.html
- Status
- This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.