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Old November 23rd 05, 04:13 PM posted to sci.electronics.design,rec.crafts.metalworking,rec.radio.amateur.homebrew,sci.engr.joining.welding
Bruce L. Bergman
 
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Default Uses for Old UPSes

On Wed, 23 Nov 2005 00:38:17 -0500,
wrote:
On Tue, 22 Nov 2005 12:55:29 -0800, "Bob Headrick"
wrote:
"Highland Ham" wrote in message
. ..


Bob , Interesting info ; can you confirm that the 18 pcs 12V battery were
in fact 9 strings of 2 batts in series (each string having a fuse )
providing 24 V ? or were all the 18 batts in parallel ?


Actually they were all in series, making it a bit nerve-wracking to replace a
battery in the string.


216 volt battery pack??? I don't think so.


No, quite possible and makes some design sense - they would not need
a heavy output transformer in the unit boosting the voltage of a 36V
or 48V battery string after converting it to a sine wave AC, as 216V
would be right around the sine wave peak voltage of 120VAC. Just run
the battery DC through two sets of power transistors to let through a
reconstituted sine wave - one for the positive half of the output
waveform, the other negative.

And it cuts the current the transistors have to pass.

-- Bruce --

--
Bruce L. Bergman, Woodland Hills (Los Angeles) CA - Desktop
Electrician for Westend Electric - CA726700
5737 Kanan Rd. #359, Agoura CA 91301 (818) 889-9545
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