[sdiy] power supply

[Roman]

I usually set the PS to current limit of 20mA. When there's short,
or something is reverse povered, it will immediately show on readout.
Such current shouldn't fry anything even if it's most delicate IC.
When it shows more than a few volts, I can safely increase limit to 100mA.
Most synth circuits take about 30-50mA, so that's most reasonable.

And I agree, checking resistance at power input is very good thing to do.

Roman

----- Original Message -----
From: "Tim Parkhurst" <tparkhurst at siliconbandwidth.com>
To: "'harrybissell'" <harrybissell at prodigy.net>; "charles kerr"
<thebadproducer at yahoo.co.uk>
Cc: <synth-diy at dropmix.xs4all.nl>
Sent: Thursday, July 29, 2004 11:50 PM
Subject: RE: [sdiy] power supply


> Here's one thing I always check on a new circuit (and I'm surprised no one
> has brought this up yet): BEFORE you apply power to the circuit, use a
good
> meter to check the resistance across the power supply lines going into the
> circuit. You will probably read a low resistance (somewhere around ten to
> 100 Ohms), but this is okay. You basically are just checking to make sure
> you don't have a dead short from + or - to ground. The resistance may also
> change slightly as decoupling and/or filter caps charge up (the meter
> applies a voltage to the circuit), but again, you are checking just to
make
> sure you don't have a dead short.
>
> Comments?
>