increase this oscillator amplitude ???

Status
Not open for further replies.
A

ahmed osama

Full Member level 6
Joined
Jul 18, 2004
Messages
352
Helped
2
Reputation
4
Reaction score
0
Trophy points
1,296
Location
Cairo, Egypt, Egypt
Activity points
2,652
Dear all

how could i increase this oscillator amplitude ???
it is abour 50Hz BJT phase shift key
changing any resistor / cap./supply in the BJT biasing , the osc. stopped !!


thanks all


 

A trivial answer: Increase VCC to 12V ;-)
You cannot get the full supply voltage amplitude from this circuit, as Q1 and its emitter resistor consume some voltage in order to operate in linear region. You could add an amplifier stage with 30..35% gain.
 

R121 in parallel to R214 affects the bias of the base ..
Try to remove R214 and see how it goes ..

IanP
:wink:
 

you can reduce the res R121 and R214 to let down bias point of Q1, set Q1 on less Quiescent Current point,you will get larger amplitude for your OSC. simultaneously, increase cap C111 to maintain (R121||R214)*C111 constant!
 

Status
Not open for further replies.

Similar threads

Menu
Log in
Register
Cookies are required to use this site. You must accept them to continue using the site. Learn more…