The company that makes that 1" cube power supply is called Bias Power Technology. Their web page is: http://www.biascompany.com/ They told me that they were about 10$ each. Check them out. Jim ----- Original Message ----- From: William Chops Westfield To: Sent: Saturday, March 24, 2001 9:38 PM Subject: Re: [EE]: 120AC to 5V no transformer > > Isn't a 630V 1uF "milspec" poly cap somewhat ... large? Say, > > close to transformer sized? > > A 1uF 250V X2-rated cap is 31 x 24 x 14mm, about 1/2 the size > of a small mains Tx. > > So how much bigger is the recomended 630V cap? :-) I have sitting next to > me a 32 x 26 x 21 mm 1.5VA PCB mount transformer with a 15V 0.1A secondary > (more power than the original poster needed, although transformer vendors > tend to keep the same size and power rating constant as they change their > secondary voltage, so this doesn't mean you can easilly get a smaller 6V > 0.1A transformer.) This particular transformer comes stamped with a bunch > of safety approvals, BTW... This makes it a close race, size wise. > > > And a lot more common than Tx's in gear available for parts-stripping > (eg PSUs) by the frugally-inclined > > There is that. From the things I've stripped recently, it takes a pretty > honking big power supply to rate a 1uF filter cap, though... > > I wonder if there's likely to be a bunch of low current "stand-by" power > supplies created as part of the "green appliance" push? I vaguely recall > seeing such a thing (5V 50mA supply in a 1 inch cube?) in a "new products" > section of some magazine recently, but I don't recall the vendor or > magazine. (Since these tend to be aimed at computers, copiers, TVs, and so > on, they DON'T run "cheap" when new, but it'd be neat to be able to start > digging them out of scrapped equipment and/or have them show up as surplus > from companies that didn't make it.) OTOH, such things tend to get cost > reduced as economies of scale come into play... > > I've been wondering if you can't do something along the lines of a lamp > dimmer circuit (triac or SCR), charging your filter cap for the last 5% of > the (occasional?) sine wave. Ripple would be pretty gross, but filter and > regulator ought to clip that off, right? It'd be somewhat analagous to > those micropower switching regulators that skip pulses when the power drain > is low... > > BillW > > -- > 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 PICList is archived three different ways. See http://www.piclist.com/#archives for details.