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 {known world}!decwrl!vlsisj!fndry!davidc vlsisj!fndry!davidc@decwrl.dec.com