[sci.electronics] circuit

RAJAH@ohstpy.mps.ohio-state.edu (09/27/89)

I would like to build a battery charger with output voltage of 4.8-5.0V 
using an input of 12V D.C. Could anybody suggest a circuit to accomplish 
this. Many thanks in advance for any help.

davidc@vlsisj.VLSI.COM (David Chapman) (09/29/89)

In article <4730@ohstpy.mps.ohio-state.edu> RAJAH@ohstpy.mps.ohio-state.edu writes:
>I would like to build a battery charger with output voltage of 4.8-5.0V 
>using an input of 12V D.C. Could anybody suggest a circuit to accomplish 
>this. Many thanks in advance for any help.

The Texas Instruments TL497 is a switching regulator IC that is reasonably
efficient and simple to use for up to 1 amp of output current.  There are 
others as well; you should be able to find them listed in the mail-order
catalogs.  The TL497 spec sheet lists circuits for step-up, step-down, and
inverting (negative output voltage) applications; I'll bet that all of the
others will too.

There was a posting earlier this year describing how to make one using a
roll-your-own inductor (transformer?) to make an oscillator without using
one of the aforementioned ICs.  Unfortunately, I don't have a copy online
any more.  Let me see if I can dig it up, scan it in, and repost it.
-- 
		David Chapman

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