8724	2013-06-13 07:15:09	Steven	POWER
Message	Date	From	Subject
Ok I have a 12v 1A Standard Power Supply that I have Scrounged. The project that I am working on Requires 12v and -12v http://xoscope.sourceforge.net/hardware/hardware.html I have been told all I need to do is reverse the Leads (that is assuming I don't need +12v) As far as I know I need both at the same time. How do I get 12v plus -12v out of the same power supply (The original author says to get it from you PC Power supply but doesn't exsplin how, plus I will be using a Laptop and not a Desk Top. If I need to build a power supply I am willing to do that.
8726	2013-06-13 07:28:49	Roger Steyaert,K7...	Re: POWER
A desktop PC power supply has both + and - 12 volt outputs. You can get a PC power supply from an obsolete PC usually for free from a computer shop. Or if you don't have room for the PC power supply if the current is low enough the voltages could be obtained from the 5 volt usb power of the laptop with dc to dc converters. at low power levels these are available as a standard part the same size as a larger IC. If you use a PC supply you probably will have to place a minimum load on the supply to get it to regulate properly. Roger K7RXV
8727	2013-06-13 07:39:57	Thomas S. Knutsen	Re: POWER
In that circuit the load on -12V is not high. There exists voltage converters that can be used, and most have high efficiency. LTC1044 may be an soloution to convert 12V to -12V. 73 de Thomas LA3PNA. 2013/6/12 Steven <smolivert@gmail.com> > ** > > > Ok I have a 12v 1A Standard Power Supply that I have Scrounged. The > project that I am working on Requires 12v and -12v > > http://xoscope.sourceforge.net/hardware/hardware.html > > I have been told all I need to do is reverse the Leads (that is assuming I > don't need +12v) As far as I know I need both at the same time. How do I > get 12v plus -12v out of the same power supply (The original author says to > get it from you PC Power supply but doesn't exsplin how, plus I will be > using a Laptop and not a Desk Top. If I need to build a power supply I am > willing to do that. > > > -- Please avoid sending me Word or PowerPoint attachments. See <http://www.gnu.org/philosophy/no-word-attachments.html> PDF is an better alternative and there are always LaTeX! [Non-text portions of this message have been removed]
8733	2013-06-14 16:57:50	Graham	Re: POWER
To follow on to Roger's suggestion, you can get an ATX power supply breakout board which makes using one of the old computer power supplies dead simple. Dangerous Prototypes developed a PCB break out board to do this, see: http://dangerousprototypes.com/docs/ATX_Breakout_Board and can be purchased online at seeeestudio, see: http://www.seeedstudio.com/depot/atx-breakout-board-bench-power-supply-p-1222.html This has everything you need to get going except the power supply and it is well supported. I have one, could have scratchbuilt one but for the price I couldn't resist. I wouldn't be without it now. Oh, and if you have never stumbled upon seeedstudio and poked around their offerings, you find that they have toooo much nice stuff that you will want. cheers, Graham ve3gtc On 13-06-13 02:28 PM, Roger Steyaert,K7RXV wrote: > A desktop PC power supply has both + and - 12 volt outputs. You can get > a PC power supply from an obsolete PC usually for free from a computer > shop. Or if you don't have room for the PC power supply if the current > is low enough the voltages could be obtained from the 5 volt usb power > of the laptop with dc to dc converters. at low power levels these are > available as a standard part the same size as a larger IC. > > If you use a PC supply you probably will have to place a minimum load on > the supply to get it to regulate properly. > > Roger K7RXV > >