From: David C Brown <dcb.home@gmail.com>
To: Microcontroller discussion list - Public. <piclist@mit.edu>
Sender: "piclist-bounces@mit.edu" <piclist-bounces@mit.edu>
Date: Tue, 28 Apr 2020 03:30:55 -0700
Subject: Re: [EE] Voltage regulator with high input voltage
Thread-Topic: [EE] Voltage regulator with high input voltage
Thread-Index: AdYdSWiFXnzgFA2jT3ewEjHmo/C+cw==
Message-ID:
 <CAFo_nNqKgY8zZijTypBgGLms9iPj0DEnPjkbmJsOG=AEZhczaA@mail.gmail.com>
References:
 <CAFo_nNp2c_0B6MP+Nv9OJBwjbo5QokUdgM8xL4zgSZAeYSXbOw@mail.gmail.com>
	<5EA71AE1.3020504@narwani.org>
In-Reply-To: <5EA71AE1.3020504@narwani.org>
Reply-To: Microcontroller discussion list - Public. <piclist@mit.edu>
Accept-Language: en-US
X-MS-Exchange-Organization-SenderIdResult: Pass
X-MS-Exchange-Organization-PRD: mit.edu
X-MS-TNEF-Correlator:
received-spf: Pass (protection.outlook.com: domain of gmail.com designates
	209.85.218.53 as permitted sender) receiver=protection.outlook.com;
	client-ip=209.85.218.53; helo=mail-ej1-f53.google.com;
dkim-signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com;
 s=20161025;
	h=mime-version:references:in-reply-to:from:date:message-id:subject:to;
 	bh=fTediVqFm7IMPe4hW5yYZwbsCC/j/8Fzuel2Hvlw7No=;
	b=hLQxln7qarLfudwr15Beagm2cHifyP0feZ3wSknNg7xabHy2UyxU+QTp22nUYksJh3
	gFOJzKF8TYD7B0mKuqD0Sq6TuORLLegqHeXglbcrDrvjQTx/GgaBDErHewEWNdG2GUMb
	zAnMkKBxdU7f+5tPIJCTpAJZdLWzw4YE+VdxNIjQOONOIWCQwEFhKDStNv6uw2x4ilah
	iBh3oV9CNqWx0PaZXUuQtlgtiQom2yiFxGQo/5IFG7yYoNQNQRvSKoGExG9FCU26EZ7O
	whjlV6I4xiEoUzkErXeh7QSizu1eCCorJ5XWxU8iNkb8kTrvgXU5W+iPFLf57G7ap3ej	9dVQ==
authentication-results: spf=pass (sender IP is 209.85.218.53)
	smtp.mailfrom=gmail.com; mit.edu; dkim=pass (signature was verified)
	header.d=gmail.com;mit.edu; dmarc=pass action=none
	header.from=gmail.com;compauth=pass reason=100
errors-to: piclist-bounces@mit.edu
list-id: "Microcontroller discussion list - Public." <piclist.mit.edu>
list-post: <mailto:piclist@mit.edu>
x-beenthere: piclist@mit.edu
x-mailman-version: 2.1.6
x-received: by 2002:a17:906:1804:: with SMTP id
	v4mr24765161eje.104.1588069866073; 	Tue, 28 Apr 2020 03:31:06 -0700 (PDT)
x-topics: [EE]
x-content-filtered-by: Mailman/MimeDel 2.1.6
Content-Type: text/plain; charset="us-ascii"
Content-Transfer-Encoding: quoted-printable
MIME-Version: 1.0

I am not worried about efficiency but I am worried about the 5watts of heat
generated in a preregulator

I am thinking of using bar LEDs instead of seven segment to reduce the
current.
__________________________________________
David C Brown
43 Bings Road
Whaley Bridge
High Peak                           Phone: 01663 733236
Derbyshire                eMail: dcb.home@gmail.com
SK23 7ND          web: www.bings-knowle.co.uk/dcb
<http://www.jb.man.ac.uk/~dcb>



*Sent from my etch-a-sketch*


On Mon, 27 Apr 2020 at 18:48, Neil <picdude3@narwani.org> wrote:

> Since you say linear (from 40V -> 5V), I'll assume you're not too
> worried about efficiency.
> How about Inline diodes or resistor to drop 40V to under 36V, then
> regulate.
> Or a zener pre-regulator?
> Or another linear regulator with the ground offset?
> Otherwise look at webench or similar for a switcher with a higher input
> range.
>
>
> Cheers,
> -Neil.
>
>
> On 4/27/2020 1:24 PM, David C Brown wrote:
> > I am designing a current monitor for my e-bike.  Using an INA169 hi sid=
e
> > current senor into a mid range PIC with a two digit LED display.
> >
> > Problem is getting the 5 volts for the PIC from the e bike battery whic=
h
> is
> > nominally 36v but can rise to over 40 volts when fully charged.  Most
> small
> > linear regulators seem to be rated at 36v..
> >
> > Current would be a couple of milliamps with the display off (most of th=
e
> > time).  Nearer 100 with the display on..
> >
> > Any suggestions
> >
> >
> > __________________________________________
> > David C Brown
> > 43 Bings Road
> > Whaley Bridge
> > High Peak                           Phone: 01663 733236
> > Derbyshire                eMail: dcb.home@gmail.com
> > SK23 7ND          web: www.bings-knowle.co.uk/dcb
> > <http://www.jb.man.ac.uk/~dcb>
> >
> >
> >
> > *Sent from my etch-a-sketch*
>
> --
> http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive
> View/change your membership options at
> http://mailman.mit.edu/mailman/listinfo/piclist
>
--=20
http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive
View/change your membership options at
http://mailman.mit.edu/mailman/listinfo/piclist
.