Maybe you will like this amplifier better than an ordinary push-pull (like I did): http://www.edn.com/contents/images/6702271.pdf page 45-46 Vasile On 11/8/09, Dumitru Stama wrote: > Hi, > I have enough voltage in my PWM signal (~4.5V) but not enough current > to drive that small speaker. I can hear the sound but is weak. I will > try with that push-pull suggested in the previous posts to see if the > results are better. > Thank you for your reply > > Dumitru > > > On Sun, Nov 8, 2009 at 7:28 PM, Vasile Surducan wrote: > > Hi Dumitru, > > The schematic posted is an emiter repeater. It does not amplify the > > voltage, only the current flow through your low impedance speaker. If > > the PWM is properly filtered, you have the chance of hearing almost > > nothing, but this is logic. > > > > Vasile > > > > On 11/4/09, Dumitru Stama wrote: > >> Hi guys, > >> i have a question. My PIC18F2520 is set up to output a PWM signal. I > >> want to amplify the signal's current and feed it into a speaker. > >> Right now using only a single PN2222A i can hear the sound but the > >> volume is quite low. > >> I tried a LM386 and the output is what i really want but only if i > >> select the 200x gain schematics. > >> I don't know what should i try now, i really want to use only simple > >> components and not a dedicated amplifyer like LM386. > >> > >> Thank you very much in advance > >> Dumitru Stama > >> > >> -- > >> http://www.piclist.com PIC/SX FAQ & list archive > >> View/change your membership options at > >> http://mailman.mit.edu/mailman/listinfo/piclist > >> > >> > >> > > -- > > http://www.piclist.com PIC/SX FAQ & list archive > > View/change your membership options at > > http://mailman.mit.edu/mailman/listinfo/piclist > > > -- > http://www.piclist.com PIC/SX FAQ & list archive > View/change your membership options at > http://mailman.mit.edu/mailman/listinfo/piclist > -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist