Treadmill motor - 180VDC

knowing that you can use Perm magnet DC motors as a generator, i picked up a treadmill with a blown board.
and it does indeed put out at least 100VDC at a nice steady walk.

Iam assuming i could increase the resistance on the treadmill by adding a load like charging a car battery, running a fan, lights etc!none of which clearly need 100+V- would i be correct in assuming i would need to put some kind of charge/ volt regulator between the two!

It would depend on the nature of the load and what voltage or current regulation the load expects.

For example, you could directly connect a common lightbulb that expects 230 volts AC, and it would probably last for years on 100 volts DC, because the heat generated will be less than normal.

More complex electronics like a fan or battery charger, yes, I think regulation will be essential to avoid damage.

Be careful wiring 100 volts DC.

The wattage of the motor will give you an idea of the current the windings are designed to safely carry.calc that once you've ascertained the maximum likely output voltage.
Incandescent lamps would make a good load bank.

i tend to treat DC or AC with the same respect - all though in this rig its only life while some one is walking it. or are you getting at the fact that you need thicker wire for DC! ( currently using the old AC power cord )

! you can tell i know noubt about this stuff.are you suggesting we need to limit how fast we spin the motor ( via the shaft as a generator) to prevent its windings failing!

If you're simply trying to load up your walking effort, then you need to connect resistive loads that can cope with 100V.
230 Volt devices that are purely resistive will be OK, but it's becoming less common to find devices that are purely resistive - even fan heaters these days have electronic controllers in them!
Incandescent lamps and ordinary bar heaters will be OK but CFL lamps will not.
It will be a case of trial and error to find the amount of loading you require. (i.e. the number and size of lamps)

If, on the other hand, you're trying to do something useful with the output of the motor, then it's a different story!
What exactly would you be trying to power with this!
As you've deduced, there isn't much out there that runs directly on 100 Vdc - most things tend to be 230 Vac or 12 Vdc etc.
Even universal power supplies such as laptop supplies which will run on 90 - 250 Vac in, need at least 128V in when it's DC.
If you want to EFFICIENTLY use the power out of the motor, then Ideally you would need a DC-DC switching converter that takes 100 Vdc in and puts out the DC voltage your require OR a DC- AC inverter that takes 100 Vdc in and puts out 230 Vac.
e.g. http://www.powerbox.co.nz/pdf/PBI2H.pdf
It is relatively easy to make a simple voltage regulator which will drop the voltage down to 12 or 24 or whatever, but it won't be very efficient - most of your effort will end up heating the regulator.

No, am saying what the minimum impedance of the load bank should be to ensure you don't overload the generator.

thanks heaps for that.
the primary use was to create a variable load so we could use it as a tread mill - your suggestion of incandesant lamps seems good easy one maybe in series with switch between each.

the secondary was the fantsey of free power - naturally. but i am thinking at this time until i understand all that jargon, maybe at the simplest the charging of a car battery(12-24v) which i guess a 100-180v supply is ok for viaa regulator ( i know i can buy them) .