Timeline for Advice to improve my microphone circuit
Current License: CC BY-SA 3.0
4 events
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| Nov 9, 2014 at 23:05 | comment | added | George Herold | @confused, Hmm it'd be nice if they showed you the response below 50Hz, be nice to see where it dropped off. Re: bias resistors, as far as the signal is concerned you should consider the power supply rails as being the same as ground. (Think about a big cap to ground on the PS rail, if nothing else.) | |
| Nov 9, 2014 at 18:49 | comment | added | confused | My frequency of interest is 20-220Hz, with I think most of my energy at around 100Hz. Oh and I do have 4 more optional gain stages on my board, but they were just overdriving when I tried them before. | |
| Nov 9, 2014 at 18:44 | comment | added | confused | Here are two links to the mic: puiaudio.com/pdf/POM-2245L-C33-R.pdf media.digikey.com/pdf/Data%20Sheets/Projects%20Unlimited%20PDFs/… I hadn't considered that R5 was part of the high pass filter. R5 I was using as my bias resistor for the mic, R38 is an option if I bridge J16. It allows me to use the DSP's mic bias output if I want to. I'll definitely try your suggestion on increasing the bias resistor and C4. I don't have a good signal generator at home maybe I have on at work I can borrow, and I'll try your suggestion on that. | |
| Nov 9, 2014 at 15:05 | history | answered | George Herold | CC BY-SA 3.0 |