Jump to content
Electronics-Lab.com Community


  • Content Count

  • Joined

  • Last visited

  1. tadgesualdo

    IC Help

    rybitski, It is true you must understand basic electronic theory to understand how to utilized IC's in circuit, especially if you want to design with them. But even then you will not totally understand how or what is going on inside them fully. So I found it helpful to view them as black boxes, if you give the correct inputs, you should get the desired outputs. Therefore often times when you can't figure out why your circuit is not working properly, and you have checked that all required input information (supply voltages and input information) then you have not other choice but to assume
  2. Hi all, Ok I have another question regarding op amp theory. What is the best way to make a op amp buffer? Most times you see two 10K resistors for this with a non-inverting input, but would not just a short between the output and the negative input work the same? What is the difference? Now with inverting inputs this seems to get more complex, because doesn't the input inpedance of the opamp have an effect on the feedback circuit, and needs to be taken into account? Thanks, TG :)
  3. I found one thanks, I have been reading, this is what I needed, but to be quite honest you do need a little bit of background to grasp all of it. It would be nice to for things to be written in a bit more common language, I miss some of the detail stuff. TG :)
  4. How do I open Ante's book, what program? TG :)
  5. Audioguru, Why don't you tell us how you really feel, eh?
  6. With regard to R3, R4, R11, and R12. The value you want depends on the other values you are using in the loop.
  7. I thought this quote from a converstation I had with another designer might help others understand the reason for pursuing a design with resistors that bleed open loop gain in an op amp circuit. The idea is to allow the op amp to function in an area that it operates in a more stable condition. For some op amps noise may be a consideration that will not make this practical, for others like the OPA637 this is a viable solution that would otherwise make the op amp unable to work in a certain application. Some have found that most op amps, even those that are suposedly unity gain stable functi
  8. I really like the idea of I2C contol of audio and home theater components. A lot of IC's use the Philips I2C standard to control a IC volume control, input selection, bass/treble controls, and anything else that we use to control with pots and switches on from pannels. Does anyone know of a controller that you could put in a front pannel of a home made home theater preamp with a few switches and knobs that could you program to contol various audio chips that use the I2C format. I know of a few guys that use the I2C interface in robotics, but don't know any DIY guys in audio that use it. T
  9. Well I haven't gotten the "noise-gain" resistor design implimented to "hear" it yet.
  10. The reason for the two op amps is that the second corrects the phase back to where it was in the begining.
  11. Audioguru, R3, R4, R9, R10, were inserted in this design based on the design notes below, see the subtitle "noise gain manipulation".
  12. Ok I am going to try to post the schematic in this post. TG :)
  13. Audioguru, While I figure out how to post a schematic perhaps you could answer a few more questions. Are these supply caps your talking about in series with the supply, or between the positive and ground of the supply? What starts to happen the further from the supply pins of the op amp you start getting with these caps? I make my own PCBs (toner transfer method) so I make my traces as wide as possible, I imagine this helps. Is there any other thing I can do to reduce inductance in working with the PCB? Also if this helps I use a +/-15v supply on the opamps. It doesn't appear at this po
  14. Audioguru, Currently the circuit I am tweaking and experimenting with is a two stage inverting opamp configuration. I really like the idea of stages and components not effecting each other, so i try to issolate and buffer them as much as possible. For instance on my first opamp stage I use the ratios of resistors that present a higher circuit impedance to the source circuits, and I use up some circuit gain by issolating the two stages with a law faked volume pot. The second stage then I have complete flexibility to do the most radical things, as this section will not effect other circuits
  15. I had higher hopes for this thread, not that some of you haven't delivered, but I was hoping this would go in the direction of some experiences some of you had in developing circuits with opamps.
  • Create New...