fala
Full Member level 5
Hello, Can anybody please halp me to understand exactly how this circuit works?
This circuit is from third edition of IC OpAmp Cookbook from Walter G.Jung page382. I understand this much that when OpAmp goes to positive rail(+15V) 1/100 of voltage appears on base of Q1 which will be about 1.05V and as a result about 0.35V on emitter resistance of Q1 that gives about 1mA current on the other hand base of Q2 has a voltage about 1.4V and emitter resistance will see 0.7V that gives about 2.1mA.
If this circuit is going to work then collectors of Q1 & Q2 should have about -100V when OpAmp gives +15V and +100V when it gives -15V because Q5 & Q6 are emitter followers for Q1 &Q2 am I right ?, but how and why? What component and how forces this voltage on collectors of Q1 & Q2 what is the role of Q3 & Q4? What is the role of R5 & R6? I will greatly appreciate any help. Thanks.
This circuit is from third edition of IC OpAmp Cookbook from Walter G.Jung page382. I understand this much that when OpAmp goes to positive rail(+15V) 1/100 of voltage appears on base of Q1 which will be about 1.05V and as a result about 0.35V on emitter resistance of Q1 that gives about 1mA current on the other hand base of Q2 has a voltage about 1.4V and emitter resistance will see 0.7V that gives about 2.1mA.
If this circuit is going to work then collectors of Q1 & Q2 should have about -100V when OpAmp gives +15V and +100V when it gives -15V because Q5 & Q6 are emitter followers for Q1 &Q2 am I right ?, but how and why? What component and how forces this voltage on collectors of Q1 & Q2 what is the role of Q3 & Q4? What is the role of R5 & R6? I will greatly appreciate any help. Thanks.