[sdiy] switching power supplies?

[Barry Klein]

I don't want to start a theory war but I would not hesitate to use
a recently designed switching supply.  They are what everything but
very local low current demand products use now.  They are very
reliable, have good safeguard features, very high performance, and
quiet.  More recent designs have higher switching frequency to
reduce component sizes and noise emissions.

If you have your doubts, buy it and try shorting out the outputs any way
you can with a scope attached to them.  Try load tests that go beyond
the specified load and see that it shuts down in a protection mode and 
recovers when
the load is removed or dropped down to acceptable levels.  Modern
supplies now should not have the crude crowbar protection but intead
will recover from high loading etc. immediately without power cycling AC.

The one you suggest is capable of full AC input range so you can use it
at home too...  You may want to add bulk capacitance locally at your
load side if necessary.  Looks like totally isolated input (no ground) so
you do not have to worry about ground offsets between AC outlets.
Depending on how quiet it is, and what your are powering with it, if RF
emissions become an issue you can use a ferrite choke on the DC 
cabling/wiring
placed near the source of the emissions - your load or the supply itself. 
They
have some of these that you just wrap the wiring around them a couple
times and snap it together to try.

Much better than taking along a huge bench lab supply or whatever...!


Barry

----- Original Message ----- 
From: "Derek Holzer" <derek at umatic.nl>
To: "Synth DIY" <synth-diy at dropmix.xs4all.nl>
Sent: Wednesday, December 24, 2008 7:29 AM
Subject: [sdiy] switching power supplies?


I've been researching PSUs again, and some upcoming gigs in North
America have me looking at switching PSUs. My main spec priorities, as I
mentioned on earlier threads, are ±15V, about 1A and fairly small size.

Curetronic here in Germany have the following on offer:

http://www.curetronic.com/curetrbau/neubau/power.htm

Power supply: [+/-15V][1,6A][AC Input 85-260V]
Protections: Shortcircuit-Overload-Overvoltage-Overtemperature
Size: 105x60x30mm
Price: 29,50 euro+shipment

I've been told that switching power supplies can be very noisy, so my
questions would be:

1) Given that this is advertised on the webpage of a fairly respected
synth manufacturer, should I take this PSU seriously in the absence of
any other spec (I've written him for more info but haven't gotten a
reply in a few weeks)?

2) Has anyone actually used this or another switching PSU successfully?

Happy holidays!
D.


-- 
derek holzer ::: http://www.umatic.nl ::: http://blog.myspace.com/macumbista
---Oblique Strategy # 60:
"Don't be afraid of things because they're easy to do"
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