biasing transistors

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brendon79
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Post by brendon79 »

I am going to build the 18V power boost with b169c. see attachment I have read that this circuit works best when the collectors are biased to 9V ( sound right??)
my question is which resistors would you tweak to bias the collector voltage for t2 and t3? (r6 and r 14) sorry its been a while since I too a electronics class
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DrNomis
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Post by DrNomis »

brendon79 wrote:I am going to build the 18V power boost with b169c. see attachment I have read that this circuit works best when the collectors are biased to 9V ( sound right??)
my question is which resistors would you tweak to bias the collector voltage for t2 and t3? (r6 and r 14) sorry its been a while since I too a electronics class


You just need to tweak R6, R12, and R13 to get t2 and t3 biased correctly, if you're running the circuit off +18V, you need to bias the transistors to +9V (half the supply voltage), this ensures that the transistors will produce the maximum signal swing without clipping, normally this circuit is designed to run on +9V so the transistors would have been biased for 4.5V on their collectors....... :thumbsup
Genius is not all about 99% perspiration, and 1% inspiration - sometimes the solution is staring you right in the face.-Frequencycentral.

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