Hello people!
I bougth a lot off transistors... alike BD139 and TIp3055 and many others with their complementary, but all them with big differences in gain. Naturally i went the electronics shops with DC gain meter in hands, but could not match a lot off PNP and NPN pairs.
Can someone send me an idea?
HELP!
If a put a small gain BD139 connected as a darlington into a tip3055 and change resistor between base to emitter,the ones normally you find inside a darlington unit, can i achieve big changes in resultant DC gain.
Let i clarify, because this is not my language:
A BD139 (alike MJE350 or 340) with a gain off 100, connected with a TIP3055 with a gain off 70..... resultant will be 7000?... and making oposite thing on other two units.... a BD139 with a gain off 70 together with a TIP3055 with a gain off 100.... same result i suppose!!!???............this way will I have a matched complementary without differences in base to emitter resistors?
Will a big changes in those resistors compensate big differences too?
And what kind off problems will be resultant of this crazy "creation"
Does someone can give me an idea of how to do with those unmatched transistors "hahaha"..... eat with catchup is not a good idea..... sit on them can be dangerous.....
Help!.....my personnal big brain teacher Jan Dupont is busy... he is always friendly and gentle to say.... I will answered you as soon as i can because i am BUSY!..... and this is alike a buzzer (the busy word) that can mean you may be disturbing a lot.... this way i decide to not disturb so much my particular genius an "guru" that is making a Joint venture...or a Joint adventure with another genius
This way, please, if someone can be helpfull will be wellcome... the others that want to have fun is also wellcome.
Carlos is the Destroyer X
"if you made a mistake, congratulations!...it proves you trying to do something!"
Thanks in advance by your kindness
You can match bipolars the same way you match Mosfets
(see www.passdiy.com ) except that you put large values
of resistance in series with the base. Because the gain of
the device is reflected in the base current, this will show up
on the Collector voltage. Just pick a value that gives roughly
4 volts with a 13.8 (car battery) supply, and you can calculate
the approximate beta (current gain) from (4-.7)/R (the base
current) as divided into the total current, or you can just match
them without knowing the beta as such.
(see www.passdiy.com ) except that you put large values
of resistance in series with the base. Because the gain of
the device is reflected in the base current, this will show up
on the Collector voltage. Just pick a value that gives roughly
4 volts with a 13.8 (car battery) supply, and you can calculate
the approximate beta (current gain) from (4-.7)/R (the base
current) as divided into the total current, or you can just match
them without knowing the beta as such.
Matching ideas, answer to Mr Pass
For me is a special honor you spending your time with me.... you are one of the best.
I will read and try to understand better visiting your site.
Explendid job you are been doing.... you can believe... I am special honored by your attention ... i will show copy of your message to friends.
Unfortunattelly i am afraid off fets, mosfets and those family.... ignorance is the name, and normally we feel afraid of things we do not understand well.
Carlos, the destroyer X
For me is a special honor you spending your time with me.... you are one of the best.
I will read and try to understand better visiting your site.
Explendid job you are been doing.... you can believe... I am special honored by your attention ... i will show copy of your message to friends.
Unfortunattelly i am afraid off fets, mosfets and those family.... ignorance is the name, and normally we feel afraid of things we do not understand well.
Carlos, the destroyer X
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