# NTNUJAVA Virtual Physics LaboratoryEnjoy the fun of physics with simulations! Backup site http://enjoy.phy.ntnu.edu.tw/ntnujava/

## Information about this web site => Request for physics Simulations => Topic started by: alfalion on February 24, 2011, 12:03:00 am

 Title: operational amplifier simulation Post by: alfalion on February 24, 2011, 12:03:00 am Hi there. I'm new to this forum. I like electronics very much and i was wondering if a simulation of operational amplifiers can be made. Something like changing the input voltage or some resistor and see what you get at the output using EJS.Some of the most important opamp categories can be found here (http://www.electronics-tutorials.ws/opamp/opamp_2.html)So is it possible?Thank you.(http://www.electronics-tutorials.ws/opamp/opamp6.gif) Title: Re: operational amplifier simulation Post by: Fu-Kwun Hwang on February 24, 2011, 11:31:28 pm I hope the following simulation is what you need!You can use sliders to change R1,R2, Vin.Click invert to find the circuit type similar to your case! Title: Re: operational amplifier simulation Post by: alfalion on February 25, 2011, 05:00:24 pm Yes, this is what i was wondering about. Thanx. Title: Re: operational amplifier simulation Post by: Tminus on June 08, 2011, 04:52:02 pm Hello Mr. Fu-Kwun Hwang, can you explain or comment the variables (what they do) used for this simulation? I want to better understand this simulation. Thankyou very much. Title: Re: operational amplifier simulation Post by: Fu-Kwun Hwang on June 08, 2011, 05:52:58 pm The key point is: the same current flow through both resistors $R_1,R_2$. For non-invert case:  $V_{out}=I\,(R_1+R_2), \qquad V_{in}=I\, R_1$so $V_{out}=\frac{R_1+R_2}{R_1} V_{in}=(1+\frac{R_2}{R_1}) V_{in}$For invert case: $V_{out}= -I\, R_2, \qquad V_{in}=I\, R_1$so $V_{out}=-\frac{R_2}{R_1}\, V_{in}$ Title: Re: operational amplifier simulation Post by: srisak31 on October 14, 2015, 03:18:15 pm  :D Title: Re: operational amplifier simulation Post by: chamDz on October 26, 2015, 05:00:24 pm i have some concerns regarding this  :-[