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Subject: Re: [Homebrew_PCBs] Drilling station 40V 3A power supply

From: "Roy J. Tellason" <rtellason@...>
Date: 2005-07-11

On Sunday 10 July 2005 04:25 pm, Nuno Tavares wrote:
> Hi Robert,
>
> The schematic is not very clear, not enough resolution.

That depends on your software. :-)

I use the firefox browser here, and once loaded all I had to do was click on
the image and the resolution on my screen doubled...

> But of what I can see, these points I noticed:
> - I think that you should move the fuse to the AC part of the circuit

There is one there.

> - The LT1085 is rated for 3A and you want a power supply for 3A. Don't you
> think it's to close?

I am not familiar with those parts or I would have commented on this as well.
That is indeed too close, and for a 3A load I'd want a regulator capable of
handling at least 5A...

> What if there's an overload? Even without overload, if you use a motor with
> this, or any other inductive or capacitive load, it's starting up will not
> be an easy one. My advise is that you use a higher current regulator, like
> the LT1084 or LT1083.

I think I'm going to have to dig out some datasheets for these parts. :-)

> Same thing with the power supply diodes. Higher amperage rating is
> better.

Yes.