Can some advise on appropriate desktop power supplies? I want to power four brushless dc motors plus an arduino mega. The motors all quote 30A each, but power supplies all quote of the order of 2A.
Thanks,
Slicc
What motors?
Well not fully decided yet, but something along the lines of this one:
Thanks,
Slicc
Turnigy D2836/8 1100KV Brushless Outrunner Motor
Spec.
Battery: 2~4 Cell /7.4~14.8V
RPM: 1100kv
Max current: 18A
No load current: 1A
Max power: 336W
Internal resistance: 0.107 ohm
Weight: 70g (including connectors)
Diameter of shaft: 4mm
Dimensions: 28x36m
Prop size: 7.4V/11x7 14.85V/7x3
Max thrust: 1130g
Hi your link shows 18A, but also suggests battery type supply to give the loadcurrent, a bit worried though when they quote RPM as 1100kv.
Can you tell us the application please, a battery supply with charger may be the way to go.
Tom....Hope to help... 
Hello,
Well, I'm just starting out in all this, but I am planning on making a quadrocopter. I checked the specs for the motors on other builds and this motor seemed a fairly close match, in fact they were quoting 950kv I think, but I figure 1100 is close enough.
Thanks,
Slicc
1100kv...950kv...are we talking about power station HT lines or a quad copter motor
But yes all the bench power supplies I've looked at are about 3A, that said a single Google search for "30a power supply" found 100s.
Rob
Well to be honest I have no feel for what a suitable motor would be, hence just copying other specs. Do you have any recommendations for a quadcopter?
Thanks,
Slicc
I don't have any idea if the motors are the right size or not, but I can define kv for the general knowledge of all involved.
kv defines how many rpm the motor will spin per volt of applied power. A higher kv motor will need a smaller prop so that it can spin faster with less resistance. A low kv motor can spin a larger prop.
Judging the overall power of brushless motors is hard. You can try to use specs like current, size, kv, and weight to get a sense of the motor power, but in the end it is usually a bit of an educated guess. Usually as long as you are close you can adjust your prop size and pitch to make things work with your exact motor KV.
kv defines how many rpm the motor will spin per volt of applied power.
Thanks, you learn summit new every day.
Rob
That would be an example of a 12V 30A power supply for $30. It's not a conventional power supply that has a nice readout or banana plugs or fine/coarse adjustment knobs, etc. but it will do the job and will definitely produce enough juice.
Alternatively and really preferably would be to buy some LiPo batteries and some ESC because you will need those for your final quad copter design anyway; then just power it off of those well testing. And you can buy chargers to rechrge them of course.
Just for the record, according to Wikipedia, it's Kv not kv.