Re: [piclist] Re: ds1666


Jun 10, 2003

 


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#1416 Jun 10, 2003

Hi to all.....



I have the ds1666 the problem is that it has a pin called (VB) it

takes -5v and I have a 12V battery how can I get the -5v from the 12v



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#1417 Jun 10, 2003

You can ground VB if the voltages on VH,VL,VW don't go below GND.

Getting -5 from +12 is kind of difficult but you can buy a power

supply from www.jameco.com - look at Jameco # 155918. It takes 9-

18VDC input and produces +5 @ 300 mA and -5 at 300 mA.



--- In piclist@yahoogroups.com, "sharkzone1" sharkzone1@y...> wrote:

> Hi to all.....

>

> I have the ds1666 the problem is that it has a pin called (VB) it

> takes -5v and I have a 12V battery how can I get the -5v from the

12v



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#1418 Jun 10, 2003

Thereis alwas Dallas/Maxim www.maxim-ic.com/quick_view2.cfm?qv_pk=1177 MAX774 3-16VDV in and -5VDC out.. -----Original Message-----From: rtstofer[mailto:rstofer@...]Sent: Tuesday, June 10, 2003 2:34PMTo: piclist@yahoogroups.comSubject: [piclist] Re:ds1666

You can ground VB if the voltages on VH,VL,VWdon't go below GND.  Getting -5 from +12 is kind of difficult but youcan buy a power supply from www.jameco.com - look at Jameco #155918.  It takes 9-18VDC input and produces +5 @ 300 mA and -5 at300 mA.

--- In piclist@yahoogroups.com, "sharkzone1"sharkzone1@y...> wrote:> Hi to all.....> > I havethe ds1666 the problem is that it has a pin called (VB) it > takes -5vand I have a 12V battery how can I get the -5v from the

12v



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#1419 Jun 10, 2003

Getting -5V from +12V shouldn't be an exceptional problem.

For instance if your project have also a MAX232 or any other 232 clone

with charge pump, you already have a -8...10V.

Using a simple 555 as an oscillator, supplied from +5V and a doubler

rectifier it's quite easy to get -5V at small current.

There is an (old) schematic for this in my site (+/- power supply):



www.geocities.com/vsurducan/electro/4TEMP/4temp.htm



here the oscillator is made with a very old 723. But a 555 or a pic pin

can be used for oscillation as well. See here too:



www.geocities.com/vsurducan/electro/c520/c520.htm



at positive and negative power supply



Of course, buying a standard negative supply is another option.





Vasile



On Tue, 10 Jun 2003, rtstofer wrote:



> You can ground VB if the voltages on VH,VL,VW don't go below GND.

> Getting -5 from +12 is kind of difficult but you can buy a power

> supply from www.jameco.com - look at Jameco # 155918. It takes 9-

> 18VDC input and produces +5 @ 300 mA and -5 at 300 mA.

>

>

> --- In piclist@yahoogroups.com, "sharkzone1" sharkzone1@y...> wrote:

> > Hi to all.....

> >

> > I have the ds1666 the problem is that it has a pin called (VB) it

> > takes -5v and I have a 12V battery how can I get the -5v from the

> 12v

>

>

>

> to unsubscribe, go to www.yahoogroups.com and follow the instructions

>

> Your use of Yahoo! Groups is subject to docs.yahoo.com/info/terms/

>

>


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