[ARC5] Power Supplies for Your ARC-5

[David Stinson]

The current ratings written on the dynamotors
are the running currents.  The starting surge current
will be much higher.  I don't remember off hand what 
the starting current for a DM-33 or DY-8 is, but I think
it's around 25 amps.
Most of these supplies have protection against surges.
If you use a lower-current supply, 
most will "crowbar" and go to zero until reset.
A 10-12 amp supply will run your receivers OK,
but it won't start a DY-8 or DM-33.

You can overcome this by using some large capacitors
in a bank to provide the surge current, while the power supply
provides the running current.  24 volts in batteries will 
also work.  Old IBM printers and antique
main frame computer equipment contain lots of these big
caps, where they served the same function.

If you use a switcher, you'll likely need to build an 
RF bypassed enclosure.  They're designed for lasers and
RFI isn't usually an issue for those applications.

Some 24-28 volt supplies at higher currents 
on the Bay right now:

1322466303
1690276274
1062389767
1688821631 (good deal on this one but will need shielding).

73 Dave Stinson AB5S

-- 
"I'd rather be damned by a thousand wrongdoers
 then by my own conscience."