Reply-To: "fred bartoli"
From: "fred bartoli"
Subject: Re: Power converter, 12v DC to 16v RMS
Date: Wed, 11 Dec 2002 09:59:24 +0100
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Bob Wilson a écrit dans le message :
> In article <email@example.com>,
> firstname.lastname@example.org says...
> >I am looking to get some help in designing a circuit to take 12v DC
> >and boost it to 16v RMS. The output does not have to be DC as it is
> >driving a purely resistive load. I also do not need 16v 60 Hz just 16v
> >RMS, any frequency will do. The load will be drawing up to 10A with
> >the 16v.
> >I have been looking at inductive boost regulators and other switching
> >supplies to base my design on. Any help with topology selection and
> >inductor size vs. operating frequency would be great. I'm trying to
> >keep cost and size down with efficiency high but it is not critical
> >yet. The main goal is a working prototype and design.
> Obviously, the simplest thing would be a 12V to 16V boost converter. It
> consists of one inductor, one switching transistor, one diode, a cap or
> and a switchmode controller. There are even lots of "Switchmode converters
> for dummies" ICs out there for those who don't know much about the
> principles and simply want something fast. National's Simple Switcher
> (aka "simplistic switchers") are a good place to start.
> In any event, it makes no sense whatsoever to try to get 16V AC output,
> all you need is DC.
> You made no mention at all of how much output current is needed. If the
> is very small (a few mA), you could even use a simple capacitive voltage
> doubler driven by 555, followed by a 16V zener clamp as a shunt regulator.
Why DC ? Why the diode ? at 10A output current, it's better to avoid it if
For a resistive load, that also *don't* have to see symetrical voltages
(only 16V RMS / 10A), the simplest one could do is the following :
| | |
| | |
| | |
| ( | |
| ( | | Load = 1.6R
12V ( | |
DC ( | |
| | |
The load being driven part time directly from the 12V source, this also
relax the constrains on the inductor.