"Lloyd E. Sponenburgh" wrote:

On Sun, 20 Dec 2009 23:53:58 -0500, GeoLane at PTD dot NET GeoLane at
PTD dot NET wrote:


My Teco VFD specifies a 70 Ohm, 200 Watt braking resistor. I did
some quick looking on eBay and Mouser. It looks like the least
expensive ones are the open tube ones - BUT at around $33 and up. Is
there a less expensive place to buy these or a different way to search
either site that would bring up the less expensive alternatives?


A couple of 250W incandescent bulbs in series will work, having a cold
resistance of about 10ohms, and a hot resistance of about 100 ohms.
They'll heat up to incandescence almost instantly (in just a couple of
cycles).

OTOH, there'll be a 100ms or so of very dramatic braking before the
filaments heat; maybe more than the VFD's output transistors can take --
dunno. Most will handle it just fine, but might trip on overcurrent.

$33/resistor isn't all that expensive, if you need more braking than the
VFD will provide without them.


Light bulbs aren't reliable.


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