Anybody seeing this message? I'm still looking for a supplier for that VB409 that someone mentioned a week ago. -----Original Message----- From: Pat L. To: PICLIST@MITVMA.MIT.EDU Date: Saturday, September 23, 2000 10:05 AM Subject: [EE:] Who stocks that ST VB409 semiconductor?!? >I am VERY interested in checking out this chip, and others like it. But so >far, I am unable to locate ANY suppliers of it. > >The Harris chips mentioned previously, are no longer in production (so I've >been told). > >The VB409 is a relitively new semiconductor, so I would assume they are >still making it. I've already checked out the usual suspects (digikey, >mouser, jameco, etc..), without any luck. I've tried to contact ST >directly, but they haven't gotten back to me (And from previous experience, >they probably won't either). > >Any help locating a supplier for this part would be greatly appreciated > >Thanks in advance. > >Pat >op1cwk@flashmail.com > > >-----Original Message----- >From: V sml >To: PICLIST@MITVMA.MIT.EDU >Date: Friday, September 15, 2000 12:27 PM >Subject: Re: [EE]: 5V DC from 220V AC supply without a transformer? > > >>I posted the brief description and link a while back, they are listed >>below again. Hope it is helpful. Beware that there is no galvanic >>insulation, and be careful too. >> >>Cheers, Ling SM (not related to STm) >> >>http://www.st.com/stonline/prodpres/discrete/vipower/vb409/vb409.htm >> >> >>The VB409 VB409SP are fully protected positive >>voltage regulator designed in STMicroelectronics >>High Voltage VIPower] technology. The devices >>can be connected directly to the rectified mains >>(110V/230V). The devices are well suited for >>applications powered from the AC mains and >>requiring a 5V DC regulated output voltage >>without galvanic insulation. VB409, VB409SP >>provides up to 70 mA output current (internally >>limited) at 5V. The included over current and >>thermal shutdown provide protection for the >>device. >> >>> > Someone told me a while ago that I can do without the expensive = >>> > transformer, diode bridge and regulator to get 5V power from a >>220 - = >>> > 250V AC line to drive a PIC with some other components like a >>relay, = >>> > triac, leds etc.=20 >>> > >>> > I remember them talk about caps and zeners..=20 >>> > >>> > (I am use to the XFormer and the well known 78L05 method) >>> > >>> > Can sombody help me with a plan >>> >>> Microchip has a application note on a transformless power supply. >>The PDF >>can >>> be found here: >>> >>> http://search1.microchip.com/ie/appnote/category/pic16/91008a.pdf >>> >>> Now here's my stearn warning in all caps: >>> >>> NOTE THAT THIS DESIGN AS WITH ALL TRANSFORMERLESS DESIGNS HAVE A >>DIRECT >>> CONNECTION TO THE HOT AC LINE. CARELESS HANDLING OF SUCH A CIRCUIT >>CAN >>RESULT >>> IN SERIOUS INJURY OR DEATH! TREAT ALL PARTS OF THE CIRCUIT AND ANY >>DEVICES >>> CONNECTED TO IT AS HIGH VOLTAGE AC! >>> >>> Note you'll have to pay attention to the reactance of the cap >>because the >>> voltage is doubled. >>> >>> Good Luck. >>> >>> BAJ >>> >>> -- >>> 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 >> >> >> > >-- >http://www.piclist.com hint: To leave the PICList >mailto:piclist-unsubscribe-request@mitvma.mit.edu > > > -- http://www.piclist.com hint: PICList Posts must start with ONE topic: "[PIC]:" PIC only "[EE]:" engineering "[OT]:" off topic "[AD]:" ad's