Homebrew PCBs

Hi Robert,

The schematic is not very clear, not enough resolution. 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
- The LT1085 is rated for 3A and you want a power supply for 3A. Don't you
think it's to close? 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. 
	Same thing with the power supply diodes. Higher amperage rating is
better.

http://www.linear.com/pc/productDetail.do?navId=H0,C1,C1003,C1040,C1055,P128
3

- These regulators are adjustable ones. This means that they can be set to
supply a voltage from 1.25V up to whatever you choose with the resistors in
the adjustment pin. If you want 40V you cannot connect it to ground
directly.

If you whish, I can send you a better schematic of an 40V, 3A power supply,
with the LT's regulators or others. Or, you can send me the schematic with
much better resolution and I can help you to solve its problems.

P.S. use my private E_mail: nuno_t@..., this subject doesn't fit in this
group, OK?

Best,

Nuno Tavares


> -----Original Message-----
> From: Homebrew_PCBs@yahoogroups.com [mailto:Homebrew_PCBs@yahoogroups.com]
> On Behalf Of Robert Hedan
> Sent: domingo, 10 de Julho de 2005 20:17
> To: Homebrew_PCBs@yahoogroups.com
> Subject: [Homebrew_PCBs] Drilling station 40V 3A power supply
> 
> Hi,
> 
> I've just uploaded a schematic of a 40V 3A circuit that I put together.
> I've thrown in every security measure I could find in the DigiKey manual
> as
> an exercise.  The file is in FILES / Power supplies.  This link may (or
> may
> not) work:
> <http://f1.grp.yahoofs.com/v1/MHDRQjmKCjHN8hORzw6Lxapg3rQLHR9sg4BZ8ePemrCI
> Kl
> pX6E8d2Q1QnZ52WUfAGgpe1uV08UyZCt9sgF5IHEcaLLyziJI/Power%20supply/Drilling%
> 20
> station%2040V%203A%20steppers.JPG>
> 
> Please let me know if I have design flaws, is the fuse rating high enough,
> components in series instead of parallel or vice versa, suggestions for
> additional security measures, improvements in filtering, etc.
> 
> This is my first power supply and I don't want to have problems with it in
> the future.  I also want to make it as robust as possible.  A separate 5V
> circuit will power the logic circuitry, this is exclusively for the
> steppers.
> 
> Robert
> :)
> 
> 
> Be sure to visit the group home and check for new Links, Files, and
> Photos:
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> 
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> Yahoo! Groups Links
> 
> 
> 
> 
> 
> 
> 
> 
> Be sure to visit the group home and check for new Links, Files, and
> Photos:
> http://groups.yahoo.com/group/Homebrew_PCBs
> 
> If Files or Photos are running short of space, post them here:
> http://groups.yahoo.com/group/Homebrew_PCBs_Archives/
> Yahoo! Groups Links
> 
> 
> 
>