Wind turbine voltage splitter

[verytricky]

An alternative circuit that switches in an additional load would be,
**broken link removed**
This is probably easier to understand. (R4 is the heater)
The relay wouldn't chatter as hysteresis is inbuilt.
<edit>This has the disadvantage that when 150V is reached it reduces the load on the turbine and the turbine would speed up. Not really desirable.</edit>

Mike.

Been doing some thinking....

If I were to obtain a second Inverter, I could wire up this second inverter as the 'load' in series with the first inverter, and then drive two of them when the voltage exceeds say 140 volts. If this 140+volts occurs, then both inverters get exposed to the current, and each would get 70+ volts. I could then let the circut run to 180 volts, and each inverter would get a maximum of 140 volts....

When the total input voltage dropped below the 140 volt mark, the second inverter would be disconnected, and the result would be only one inverter getting the say 139 volts.

Does that work in theory?

 

[Percul8or]

did you go any further with this?

Hi Verytricky,

did you find a good solution for this?

Thanks

Perc

 

[verytricky]

No - in tests the gizmo would sometimes switch at 160v and occasionally would not switch off when the voltage got low as 120v.

I was worried about blowing the inverter, so I stopped the experiment.

If I could find a reliable way of doing it, I would definately contine to experiment.

 

[Percul8or]

turbine brake

Hi VTricky,

Thanks for getting back to me. I have started to do a bit of playing with this. I want something that increases the load on the turbine as the voltage gets close to the limit rather than brake the turbine completely.

I bought a 2nd hand variac on ebay for $50 so I can simulate a turbine and run it through a bridge rectifier to get DC.

So far no joy with 150v Zener and a 1K 5W resistor. The zener does not seem to avalanche at 150V. It just gradually increases the current going through it as the voltage increases from 50v to 160v with the above circuit.

Any smart guys here who can suggest a better circuit??

 

[verytricky]

The result I was getting was simulated by adding 12v batteries in series to give me my magic number for testing. I use the home alarm 1AH batteries for the experiment. I first linked 8 together to give me around 115 volts. Then I added a battery at a time till the circut tripped.

As a load I used a 200 volt light bulb.

When I added an additional three batteries, I had 157 volts and the circut did not trip. On the fourth additional battery, measured at 171 volts, the circut opened. Then I started removing batteries to get the circut to flow through one side only, and it stayed on all the way back down to my origional 8 batteries. When I was thinking what the hell had I done wrong, it turned off suddenly, about 5 minutes late!

I definately need it to switch at 150 maximum. no more at all! and I would want it off when it dropped below 150 as well.

Any ideas?

 

[Percul8or]

Ideas

I have a couple of ideas. I'll give them a try and let you know in a few days

 

[Percul8or]

Initial Circuit

I put together the (hopefully attached) circuit.

Unfortunately the 741 will not behave as expected. The LED just stays on.

I have used the 741 op amp to perform similar functions in the past but for the life of me I can't get this to work.

Any ideas folks???