From: Richard Prosser <rhprosser@gmail.com>
To: Microcontroller discussion list - Public. <piclist@mit.edu>
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Date: Mon, 13 Sep 2021 00:53:06 -0700
Subject: Re: [EE] LM1084 regulator question
Thread-Topic: [EE] LM1084 regulator question
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As others have said, a switching (buck) supply is really what you need.
A quick and dirty alternative may be an incandescent headlamp bulb or 2 in
series with the regulator. Either a 24V type or 2 x 12V ones in series.
Something like 48W  to 60 W might be worth a try. Things will still get hot
though.
RP

On Mon, 13 Sept 2021 at 02:35, William Couture <bcouture@gmail.com> wrote:

> Hi!
>
> I need about 3A of 5V, with a 24V supply.  I'm trying to use a LM1084 in =
a
> TO-220, which is
> rated at 5A output.
>
> However, when I try to pull more than about 250mA, the regulator becomes
> very hot and I
> start getting dropouts.  A heatsink does not help.
>
> I have an electrolytic capacitor on the output, not a tantalum like in th=
e
> datasheet, could that
> be the problem?
>
> I tried putting a 7805 in the circuit (with appropriate pinout changes) a=
nd
> it's fine up to 1A,
> so the problem is the LM1084 itself.
>
> If the LM1084 will not work, can anyone suggest a low-cost circuit to get
> 3A or so of 5V
> from 24V?
>
> Thanks,
>    Bill
>
> --
> Psst...  Hey, you... Buddy...  Want a kitten?  straycatblues.petfinder.or=
g
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