The AVR project

[adhall]

rcavictim:

Regarding the relationship between load on the Z winding and distortion:
I searched through the forum for references on this. I did not find any indication anyone has tried putting a dummy load on the Z winding while powering the rotor with from another source (although I did find a suggestion to do this).

Could you kindly point me to the post(s) regarding this?

Best regards,
Andy Hall

[Doug]

I thought about the distortion and Z winding all night....

First I'm way out in the clouds on the cause of the distortion, its just transformer action not anything complicated involving the flux in the air gap.

Second the 50 hz taps in might be able to produce some usefull power. Possibhly on the order of 12-24 v.

Andy is right we need to run a test on the Z winding to see exactly what its doing and what noise it transmitts.



Doug

[adhall]

Hi Doug,

I'm working on getting a 5 kW ST head. Once I have one in hand, I will be able to run all the tests I want.

By the way, even though I haven't posted much lately, I am making progress on the AVR. I have been communicating with people outside the forum as well as doing some research on my own. And thanks to the insights and suggestions of one of the other forum members, I believe I have a workable electronic fix for the "flicker" problem in hand.

Best regards,
Andy Hall

[Doug]

Cool!

I dusted off an old scope I found at work. Its a very tiny and old single chanel hand held but it should be of some use for this.

Maybe I can do some testing...

Doug

[peterako]

Hello to all of you for this intresting subject and also for me it is amodification area on my gen.
It is not a ST but close by.

the item about the z winding is maybe more difficult because on the high but freq. burst from the flicker it is like a radio wave.
And in this provides the problem that diconection from the z winding is only greating a open high freq. transformer and will disturb using the cables normal radio trafic.
Oke this is nota problem if you are in the jungle or dessert far away from anybody. but for somebody living a little bit more tight. Will have problems.

maybe it is better to use a capicitor, this will be a nice experiment i think because the delay can help the filter maybe

Greeting from Greece

[cujet]

My ST head will not make quality power. It will not run the micro, the APC batt backups for the TV or the computer. This makes the power produced a big problem, as I cannot use the things I need when the power is out. In fact, nothing that it runs sounds right. The wave form is not good, the lights flicker and the voltage is low, even with the adjuster all the way up.

I have been hopeful that one of the AVR genius' here on the forum would have found a fix by now.

There may only be one practical solution for this issue, get a real gen head with real AVR.

[theboss]

did someone checkout stabimatic.. their 5000watt 220V AVR costs about $80 here...

[kltrider]

I also will need an AVR when I install the newest ST head at the house.  Keep in mind, when designing this unit, not all ST heads have the 50 HZ leads. I build custom gensets for the aircraft industry using many types of engines and heads. Only 2 of at least 22 AC heads I have used incorporate 50 HZ taps.

[adhall]

Gentlemen:

Please note I have put my involvement in the AVR project on the back burner for the time being. I am in the process of assembling my own slow-speed gen-set right now and it will be several months before I have time to start working on this project again.

If you are in a hurry, you might try contacting the vendors who also frequent this forum. I won't mention any names because I have no personal experience with any of them and don't want to appear to be recommending anyone in particular. Just do a search for "AVR" on this forum and you can find them for yourself.

Also, please note that in this case AVR refers to the Automatic Voltage Regulator that controls the output voltage of ST head itself. Some of the posters have been referring to an different device the uses the same acronym. The other "AVR" is a free-standing device that adjusts the line voltage to account for brownout or over-voltage conditions.

Best regards,
Andy Hall

[mjn]

My copy of the utterpower CD was pretty old, so I ordered a new copy last month. There is a full schematic for an AVR on the most recent copy of the CD.

The AVR uses a 60 volt step down transformer, rectifier and capacitor to provide field power.  On startup, a 12v battery supplies power to the field until the output gets high enough to take over.

Another step down transformer + rectifier + cap + divider resistor provides a voltage which follows the main voltage.  This voltage is fed to a comparator.  An adjustable reference is the other input to the comparator.  When the main voltage is less than the reference, the comparator drives a MOSFET which drives the field.

[mjn]

Here is my interpretation (over simplification) of the utterpower AVR:


MODERATOR MODIFIED... WE SHOULD NOT POST OTHERS WORKS WITHOUT PERMISSION

It may not be off the CD, but it is your copy, of Georges work.  Key being Georges work.

[mobile_bob]

mjn:

is that schematic off the utterpower cd?

if so, is it not copyrighted?

i am not sure i would be comfortable releaseing stuff from the utterpower cd without prior consent

bob g

[mjn]

The schematic above is mine.  I have no idea if the above circuit will work.  I was attempting to illustrate how the version on the utterpower CD works without "giving it away"

I'll gladly pull the schematic if the consensus is that I've crossed the line on the copyright issue.

[mobile_bob]

mjn:

ok, if it is your schematic i see no foul.

fair enough

bob g

[retardo]

Hello Martin,
You have crossed no line. Thanks for your honest posting.

"Ok with me, might be on there somewhere, but I didn't draw it."

The above is a direct quote from George.

Have followed with interest your project, and looking forward to hearing about the birth of the new slow-speed engine.

 Answer provided by Retardo Mentalbum.