5 ms·
Use old style opamps for this btw, they are more susceptible to this, like LM741 NE553, LM883, ... If you are ok with putting your cellphone on the detection bo
by Qantourisc 10y ago
Use old style opamps for this btw, they are more susceptible to this, like LM741 NE553, LM883, ... If you are ok with putting your cellphone on the detection box, all you need is an opamp driving a small speaker, and the opamp requires no input. Or you could just hook an antenna on it. If you want I could try, but I have more exiting things to do :)