From: Gary Tait
Subject: Re: Difference between AC adapter and charger?
X-Newsreader: Forte Free Agent 1.92/32.572
Date: Thu, 17 Oct 2002 15:44:45 -0400
NNTP-Posting-Date: Thu, 17 Oct 2002 15:44:44 EDT
Organization: WorldCom Canada Ltd. News Reader Service
On Thu, 17 Oct 2002 10:22:23 -0700, DaveC wrote:
>Many appliances that run on batteries have "wall wart" supplies. Each of
>these supplies run the appliance, but some are designed to also charge the
>What is the difference in circuit design between these? One is simply a
>voltage-regulated supply. But isn't this connected in parallel with the
>batteries, and won't it "try" to charge the batteries, making it, in essence,
>I guess the question I'm asking is how a battery charger works (compared to a
>regulated supply), and additionally, how it charges batteries while the
>batteries are connected to a load. I mean, doesn't driving a load make
>charging a battery a more difficult task (ie, the changing voltage due to the
>changing load, like a user using the walkie-talkie to transmit as compared to
>just idling, receiving)?
>Let's assume NiMH AAA batteries x 4, a 4.8v supply.
"Charger" wall warts tend to have current limiting, and are often
DC supplies are filtered, with either some or no regulation.