op amp question

Hello, I have to design a single op amp circuit that has only +15v, -15v and GND as input and outputs a symmetrical PWM signal (+V and -V) with adjustable frequency and duty cycle. I have something that works partly but not completely, I can adjust the duty cycle from ±60% to ±100% but af that...

Im stuck on my electric curcuit homework could u guys help me

I was trying to derive a model for Opamp Hartley oscillator. I used a R at mouth of opam to increase the output impedance. So i tried including it in calculation. As the opamp is modeled as output voltage of Avi so using a R in series with it with help me to reconfigure the circuit changing the...

Hi I'm currently stuck on current question. Consider the following OP amp circuit in . Obtain the gain vo/vi of the amplifier. What I can see is I can find the voltage on positive and negative pin of top OP amp, which is 30/50*vi (because positive pin of top OP amp is in parallel with 30...