Cheap dump load

[frackers]

As promised, a picture of the 'wire wound resistor' made from fence wire.

Its 1m long and 0.5m in diameter and with something like 45m of wire on it - it presents a resistance of 1.88 ohms

I might try it if we get any wind - its really for testing the genny off the tractor PTO

[wooferhound]

Looks like a great idea for a Camp Fire Starter

[Bruce S]

Hey wooferhound;

   I was going to say something of the same :-)

Depending on the heat, I'm thinking those wood stand-offs will do just that.

Cheers

Bruce S

[ghurd]

Sounds safe to me, for 12V.  About 7.7A, 110W.

Only ~1W in 16" of wire?

G-

[TomW]

Interesting. So at say, at 10 amps its 188 watts [not a problem] but at 100 amps it will be creating 18.8KW? Spread out over that length I wonder how hot any one point of contact will get?

Likely quite safe for a lot of testing use before it chars too much. How many of you push 100 amps for long?

Great use of stuff on hand especially in spring during fencing season.

I don't see the gage mentioned?

Tom

[DamonHD]

Could be an alternate way to keep the deer out...  First 300V on the nose.  Then 300C on the nose if they don't wise up...

Rgds

Damon

[SparWeb]

Don't people hang those things over their patios to zap bugs?  Hehe  Looks nice.

[frackers]

Seems like it was one and a half hours well spent :-) And all scrap materials - even the nails were reclaimed from a bunch of pallets!

It will be on a 24volt system so I expect that I'll only run it up to about 35volts (i.e. without a battery bank, just the genny on the PTO) where the full length will be dissipating 650watts (35^2 / 1.88).

For higher current tests where I want to load the genny to about 40amps at 28volts (max design charge current on a fully charged bank) the 1120watts will be spread over about a third (0.7 ohms for that load of course) of the wire length so I expect it will cook then - so long as the smoke isn't the magic variety that makes all the electrons go round I think I'll be OK...