An 'off-line' switcher (like in a computer), which is driven directly off the AC line will still have a higher frequency transformer in it, and will almost always contain a full wave rectifier on the incoming A/C power. This removes any DC component from the load the switcher presents to the house mains. Bob Ammerman RAm Systems (contract development of high performance, high function, low-level software) ----- Original Message ----- From: "Dale Botkin" To: Sent: Monday, July 02, 2001 6:58 PM Subject: Re: [EE]: Bulb Life (x:Modulating headlight) > One does... the other is a switcher. > > On Mon, 2 Jul 2001, Michael C. Reid wrote: > > > your bench power supply has this thing called a transformer that isolates it > > from the main power input! > > > > -----Original Message----- > > From: pic microcontroller discussion list > > [mailto:PICLIST@MITVMA.MIT.EDU]On Behalf Of Dale Botkin > > Sent: Monday, July 02, 2001 4:43 PM > > To: PICLIST@MITVMA.MIT.EDU > > Subject: Re: [EE]: Bulb Life (x:Modulating headlight) > > > > > > On Mon, 2 Jul 2001, Michael C. Reid wrote: > > > > > Regarding those small disc shaped devices, I understood that some brands > > > were diodes, dropping the voltage in half to save on bulb life, if you > > like > > > the idea of DC being introduced into the power grid of your home. > > > > Ummm... no more than my bench power supply does. > > > > Dale > > -- > > A train stops at a train station. A bus stops at a bus station. > > On my desk I have a workstation... > > > > -- > > http://www.piclist.com hint: The list server can filter out subtopics > > (like ads or off topics) for you. See http://www.piclist.com/#topics > > > > -- > > http://www.piclist.com hint: The list server can filter out subtopics > > (like ads or off topics) for you. See http://www.piclist.com/#topics > > > > > > -- > A train stops at a train station. A bus stops at a bus station. > On my desk I have a workstation... > > -- > http://www.piclist.com hint: The list server can filter out subtopics > (like ads or off topics) for you. See http://www.piclist.com/#topics > > -- http://www.piclist.com hint: The list server can filter out subtopics (like ads or off topics) for you. See http://www.piclist.com/#topics