Trying Out Ideas

[SparWeb]

Two weeks with only one good breeze that got the mill going.  Oh well, I've had time to "dig in for winter" - literally:

I have installed some new instruments:

No news on how well they work, I only had 20 minutes of enough wind to activate the tachometer.  There wasn't enough time to take any simultaneous measurements to calibrate it.

The temp sensor seemed like a good idea at the time, but so far it hasn't read anything - again due to no wind.

[I'd show a picture, but I've uploaded it twice, and it won't display.  Go figure.]

Finally, I now have some resistors that I can "switch in" on the AC inputs.  Observations a month ago confirmed my suspicion that the 8 foot prop, which was built for a smaller generator, isn't big enough for this generator.  A bit of line resistance is the cure for that.  I am trying about 1 ohm on each phase (the actual resistors vary a bit - I took what I could get from the surplus store)  The real solution, of course is to put on a larger prop, but making prop blades is a task I am saving for the winter months.

But I'm still waiting for the wind...

[BruceDownunder]

Nice work there,,  would it be possible for you to post the Cct and whatever you did to get that tacho to work,please.  I've got the same type tacho ,I think , but for the life of me can't get it to work --

Thank you ,

Bruce

[sPuDd]

I've been considering the idea of a temp sensor embedded in the coils too.

The flux issue and electrical noise would make it fairly hard.

Maybe the otherpower admins can figure out why you pic does not work.

sPuDd..

[SparWeb]

Here's a schematic of the system, as it is today:

The tachometer taps off of two AC wires.  I run it through a transformer to "step-up" the voltage.  The instrument will only read when the speed is over 200 RPM, and currently the measured RPM and the actual don't agree.  The secondary winding of that transformer doesn't have much resistance, so it's like I am shorting that phase when I switch to "TEST".  Next time I have it open, I'll put in a resistor.  It isn't my biggest problem, at the moment.

I need a set of big resistors in-line with the incoming AC.  I could get into trouble if a LOT of current if forced through these resistors.  They are rated at 300W, so if the generator goes over 20 Amps, then they would be too hot.  I've already seen 15 Amps and the heat wasn't excessive.  But I'm risking an open-circuit condition, just when the wind is high.

Time to order a proper set.

Here's another try to post the temp sensor installation:

I'm looking through the housing, with the ends of the motor taken off.  The sensor is pressing against the stack of laminations, with a bit of thermal grease to help the contact.  So far, the needle hasn't risen off the peg.