4 Feb
2015
4 Feb
'15
7:02 p.m.
A pretty good dummy load is a globar resistor in a bucket of mineral
oil. Remember the Heathkit "Cantenna"? Basically a big carbon
resistor; still made by Kanthal-Globar today. If you don't need a
non-inductive load, a bunch of plain old wirewound power resistors,
suitably cooled will do.
--Chuck
On 02/04/2015 06:43 PM, Jacob Ritorto wrote:
wow, good catch, Noel. I'll pass this on to NASA
;)
On Wed, Feb 4, 2015 at 7:56 PM, Noel Chiappa <jnc at mercury.lcs.mit.edu>
wrote:
From:
Jacob Ritorto
My NASA EE buddy recommended working up an
appropriate load from
regular household lightbulbs. They won't light, naturally, but you
can
dial in your load by simply choosing certain
wattages and doing the
math.
Err, both tungsten and carbon filament incandescents have very different
resistance when hot (lit) and cold. To make it even more, they are of
opposite
sign: with tungsten, the resistance increases as it heats up (a nice
stabilizing feedback), and with carbon, it goes the other way. So if you're
not running enough current to light the bulb, you can't use the printed
watt
rating; you'll have to use an ohm-meter.
Noel