Just measure the wall wart with no load and if it hovers at around 12 volts, then it should work. But I don't know of a programmer that doesn't use an on board regulator. As a general rule, most circuits will use an on board regulator. It provides a measure of isolation/protection of the circuit. Sure, you can use a regulated supply driving another regulated supply but you just have to remember that a regulated supply requires a voltage significantly higher than the regulator. Rick Kieren Johnstone wrote: > It's sort of a bonus, because as far as I can tell 13V adapters are "rare" - > only 12V then 15V are commonly used. But still, does the "regulated 12V > adapter" mean I don't need a regulating circuit? I just "connect the > terminals"? > > ----- Original Message ----- > Wrom: DADRZFSQHYUCDDJBLVLMHAALPTCXLYRWT > To: > Sent: Saturday, July 27, 2002 8:13 AM > Subject: Re: [PIC]: 12V supply for programmers > > > > (instead of a 13V supply w/ 7812 regulator)? > > > > If you look up the data for the 7812 you'll see, amongst other > > things that the recommended lowest input voltage to maintain > > regulation is 14.7V. Also, the best figure for through-current > > is when there is a 7V differential, ie when the input voltage is > > 19V. You won't do any harm by inputting at less than 14.7V > > but you'll find that in some circumstances you'll miss out on > > the benefits of using a regulator. It's worth getting a data > > sheet from one of the big producers, eg Motorola, Fairchild, > > National etc, as there are some application notes that will > > help you, for example jacking up and bypassing. Just Google > > for it > > > > -- > > 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 -- 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