Alt-BEAM Archive
Message #08614
To: "'beam@sgiblab.sgi.com'" beam@sgiblab.sgi.com
From: Wilf Rigter Wilf.Rigter@powertech.bc.ca
Date: Mon, 27 Dec 1999 15:31:56 -0800
Subject: [alt-beam] Re: AC
Hey Bumper!
What do you need this for? With few exceptions, most "low power" equipment
connected to the mains first step down the voltage, rectify it and feed it
to a low voltage dc power supply. See my point?
Assuming you need really need a 60Hz - 120VAC sinewave at (for example) 5mA,
you can use a small 120 to 6V center tap step-down transformer with a couple
of mosfets, some passive components and two D size batteries. The current
drain from the batteries will be about 300mA and fresh batteries will last
about 3 hours in continuous use. The voltage will drift down from 120 to
90VAC at the end of battery life. Does that sound like the solution you
need?
regards
wilf
> -----Original Message-----
> From: Bumper314@aol.com [SMTP:Bumper314@aol.com]
> Sent: Sunday, December 26, 1999 6:21 PM
> To: beam@sgiblab.sgi.com
> Subject: Re: AC
>
> In a message dated 12/26/99 5:45:02 PM Mountain Standard Time,
> danndom@mbox5.singnet.com.sg writes:
>
> > what frequency? you may want to look at maxims catolog. they are good at
> > this stuff
>
> Well basically just mimicing what comes out the wall...just with much less
>
> current and running on battaries...so isnt it 60hz out of the wall?
>
> Steve
8615 Mon, 27 Dec 1999 18:48:58 EST [alt-beam] Re: AC beam@sgiblab.sgi.com Bumper314@aol.com In a message dated 12/27/99 4:30:52 PM Mountain Standard Time,
Wilf.Rigter@powertech.bc.ca writes:
> What do you need this for? With few exceptions, most "low power" equipment
> connected to the mains first step down the voltage, rectify it and feed it
> to a low voltage dc power supply. See my point?
>
> Assuming you need really need a 60Hz - 120VAC sinewave at (for example)
5mA,
> you can use a small 120 to 6V center tap step-down transformer with a
couple
> of mosfets, some passive components and two D size batteries. The current
> drain from the batteries will be about 300mA and fresh batteries will last
> about 3 hours in continuous use. The voltage will drift down from 120 to
> 90VAC at the end of battery life. Does that sound like the solution you
> need?
phew...well let me tell you about what i need to drive...Have you even seen
those green indiglo night light things that just plug right into the wall and
will never burn out....well what i plan to do is backlight some stuff for
fun...calculator comes to mind, i found that for a useable glow at the size i
have it (the stuff is really cool, and its cutable) it pulles about 13mA at
115V, so i was hoping to get a calculator that could run this with its
regular Lithium ion battery. If not then i would get some smaller desktop
kind that used 2 AA's...just a thought
Steve
8616 Mon, 27 Dec 1999 18:36:22 -0800 [alt-beam] Re: AC "'beam@sgiblab.sgi.com'" Wilf Rigter That the standard electroluminescent backlighting method for LCDs and such
and there are numerous circuits that will work. Aside from prepackaged ones
you can buy for about $10-20, you can build your own ultra low power unit by
checking out the "555" circuit section at the ZETEX website.
enjoy
wilf
> -----Original Message-----
> From: Bumper314@aol.com [SMTP:Bumper314@aol.com]
> Sent: Monday, December 27, 1999 3:49 PM
> To: beam@sgiblab.sgi.com
> Subject: Re: AC
>
> In a message dated 12/27/99 4:30:52 PM Mountain Standard Time,
> Wilf.Rigter@powertech.bc.ca writes:
>
> > What do you need this for? With few exceptions, most "low power"
> equipment
> > connected to the mains first step down the voltage, rectify it and feed
> it
> > to a low voltage dc power supply. See my point?
> >
> > Assuming you need really need a 60Hz - 120VAC sinewave at (for example)
>
> 5mA,
> > you can use a small 120 to 6V center tap step-down transformer with a
> couple
> > of mosfets, some passive components and two D size batteries. The
> current
> > drain from the batteries will be about 300mA and fresh batteries will
> last
> > about 3 hours in continuous use. The voltage will drift down from 120
> to
> > 90VAC at the end of battery life. Does that sound like the solution you
> > need?
>
> phew...well let me tell you about what i need to drive...Have you even
> seen
> those green indiglo night light things that just plug right into the wall
> and
> will never burn out....well what i plan to do is backlight some stuff for
> fun...calculator comes to mind, i found that for a useable glow at the
> size i
> have it (the stuff is really cool, and its cutable) it pulles about 13mA
> at
> 115V, so i was hoping to get a calculator that could run this with its
> regular Lithium ion battery. If not then i would get some smaller desktop
> kind that used 2 AA's...just a thought
>
> Steve
8617 Mon, 27 Dec 1999 21:57:00 EST [alt-beam] cap basics beam@sgiblab.sgi.com Blumojo13@aol.com Can someone fill me in on some basic questions? Caps can be connected in
parallel but not in series, right? Now if you hooked a 10K 6.3volt cap to a
1381L SE would this cap fully charge if your power source was adequate? How
do you determined which cap will work on any particular application?
Blumojo13
8618 Tue, 28 Dec 1999 03:12:39 GMT [alt-beam] SALE beam@sgiblab.sgi.com "Jason -"
Hie all i think i am going off of them beam thinghy...i am selling all my
stuff...i have 4 servo two airtronics and two from hitec...i will be selling
them at 7USD each...all modified......so if anyone is interested email
me......
______________________________________________________
8619 Tuesday, 28 December 1999 2:17 cap basics beam@sgiblab.sgi.com Blumojo13@aol.com
>Can someone fill me in on some basic questions? Caps can be connected in
>parallel but not in series, right? Now if you hooked a 10K 6.3volt cap to a
>1381L SE would this cap fully charge if your power source was adequate? How
>do you determined which cap will work on any particular application?
> Blumojo13
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