> > How about a recommendation on the current limiting function?
> >
> > In the longer term I would add one of those digital voltmeter boards
> > (can you still get them) that used a 40 pin LSI and 4 digit 7 segment
> > display, so you have a permanent voltmeter on the output. For extra
> > brownie points make a project out of a PIC that has a 12 bit ADC, and
> > a keypad for setting the voltage, and maybe also current limit, and be
> > able to display both current and voltage.
>=20
> FWIW I have a PSU right here on my desk that has keypad entry of voltage =
and
> current, and I really don't get on with it.  It's very easy to accidental=
ly press
> the wrong button, or not notice that the decimal point was missed and sud=
denly have
> 10x more voltage than you actually wanted.  To be fair you can set an ove=
r voltage
> protection level to ensure this doesn't happen, but you have to make sure=
 you type
> this in correctly as well.
>=20
> The PSU underneath in (Keithly 2400 Sourcemeter) is slightly better - you=
 select
> each digit in the voltage and increment or decrement it, but it's still n=
ot a
> pleasant interface.  If I was making my own digitally controlled interfac=
e, it would
> use a rotary encoder, and it would have pre-settable upper and lower limi=
ts so you
> could crank the voltage up or down with impunity whilst watching a scope =
display
> etc.

Yes, I have a 2400, and have to admit its front panel interface is not terr=
ibly ergonomic. It would probably be preferable to remote control it.

The only power supplies I have with keypad interface are Thurlby Thandar 35=
V 10A units which are rather overkill for the OP - but they are nice units.=
 In addition to the keypad interface they have a rotary knob to fine adjust=
 once the voltage is set, and then once current is being drawn there is a s=
maller display showing the VA being drawn from the supply.

This is a later version of the ones I have http://www.tti-test.com/products=
-tti/psu/tsxp-series.htm



--=20
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