This is a multi-part message in MIME format. ------=_NextPart_000_001E_01C455FB.B1C44A00 Content-Type: text/plain; charset="Windows-1252" Content-Transfer-Encoding: 7bit > But how a PWM can be AC and DC I just don't get Look at it this way - the PWM has a voltage about which it swings, IOW it is either side of 2.5V. As you decrease the amplitude of the PWM the DC offset becomes apparent. This is true of any waveform. It's something that has to be considered when using opamps for example -- http://www.piclist.com#nomail Going offline? Don't AutoReply us! email listserv@mitvma.mit.edu with SET PICList DIGEST in the body ------=_NextPart_000_001E_01C455FB.B1C44A00 Content-Type: image/gif; name="PWM-ac.gif" Content-Transfer-Encoding: base64 Content-Disposition: attachment; filename="PWM-ac.gif" R0lGODlhSwFkAIAAAAAAAP///ywAAAAASwFkAAAC/oyPqcvtD6OctNqLs968+w+G4kiW5omm6sq2 7gszwAwENXLH+s73PpmzJYK/ovGI7BGFhmXyCY1KN7ScdYrNareyQ83JDYvHuyuxOoOg12w2tZ0m y+ecq7dOzdP3fA9tiKcBNjHYZ3joUhihqIbo+Jiol8EIWWk5KYlBecnZ+bDZANrlSVoqIbqAqqBq 2vrIipPpOmsKeydIm1sra2Gr+8vly4QJXAwpjGysjJiMu/y810wMTT0mrVmdHXZ9Iaz9zcLdCwJX vvZm7g3+JF6hfjuNvd7aTvHexOs+T59vT95PaN8uZ/ECFRwnkFS9gB8WnkqoEODDhhIXQfTk0CJF /oLyLl7K2GjjQX0eP1YM6efkp5ImOXb75xIhy2MqHdwb1jHnTGY1Q8Ec6W/nq56jUsYkKZTn0aBG gTJMegjkSpE6ZULtI9Xmz6pIr/LJ6pPqy6VerRFNtXWs07Lbzq5Ka1Ut2zlgi3aoi3YuHbxvxcb9 qyldOnRwsvwZcrgFX0B+u8olO3GtYXj4YiyO1Zgp18eANe/FbNkt46abn5YRDSVIFRiXKfNoHQJ2 E8G0a8cZ3VcxatenIYfbfaTQTdOcHfeWvMJ24c+5h0cu/fw1cKhoKifW7Rulkul6fch2nn1qdzLf i8geLz281h/n0esoz567+9Dqw3qXP/8F/Pv1z/NjxU9acf5V0l5mxA1oSYEBdoagIwreBWCDUjxo EHQS/tcfChRemMSGGebG4VAfmuBhiOZFWKGAJkaD4nTgrcgfcr+NCOMUJVqoXY1ftUgjbzrSxeMk yrnxI4YyFjngjUh6pOSSEDXppEBQRjnPlFSCY+WV2mSpZTVcdgnNl2AuI+aYrMVxBn1HmkneHWmy FiSb8VnnY3JxyrkdnZXB2SOeE8LzxXE4+imGHUKcUd0JQxJJqCGG4tToitdBGmmlll6Kaaaabspp p55+2mkBAAA7 ------=_NextPart_000_001E_01C455FB.B1C44A00--