The AVR project

[Doug]

I don't know a thing about this fellow or how well his stuff works but I think its worth posting a link especialy if you live in Canada.

Of particular intersts are the controlers and he has an AVR unit .

Never spoke to him.....

http://www.wattpower.com/wpindex5.html

Can't say anything suprises me any more. This company seems to be selling 3 AVRs and all kinds of metering. Happy hunting guys

http://www.made-in-china.com/showroom/cnekai/product-list/Voltage-Regulator-1.html

Doug

[t19]

I have spoken with this guy. 
Nice guy..... once you can get him to respond and give you a price

Found him a little pricey

Andrew

[Doug]

A lot of that stuff is going to be CSA certified or aproved, a certified engineer selling stuff like this without it would be kissing his iron ring good bye.

A lot of hand made stuff like the controls. Think he's expensive? Ask me for a quote with localy sourced parts...

On second thought don't ask .

Since you already contacted him  Andrew why don't you ask him to hock some wares and provide some prices for us. At the least its a refernce point.

Doug

[nikos]

Doug,

You are not getting the jist of what I said.  Please read it again.

It is like the Z winding represents your big toe, and you have just stuck it into a calm pool of water.  It causes ripples in the magnetic field by being there. These ripples end up on the output of the alternator, apparently by transformer action. By leaving it completely disconnected, i.e. NOT using it as a source of power for any purpose at all, it is the same as unwinding it from the alternator frame and selling it to the scrap man.  It is not there to induce ripples in the magnetic field.

Hi list,

Jumping in a bit late here, with what might simply be a brain fart.
If the above is assessment wrt induced distortion is correct (I've not seen the Z winding inside an ST), but is it possible to replace the single Z winding with a contra wound pair, in that way to possibly achieve cancelations of of induced fields? Haven't really thought this out yet, but one winding could be connected to a second bridge and also power the field.

Or keep the original winding, and add a second z winding 180 deg. opposite and feed the existing bridge (push-pull anyone?)
One local rewinder here add field windings to replace cooked or NLA avrs, mostly old industrial gensets.... I know it works, albeit I dont know how cleanly the output might be..

I am concerned that some report that they cant really power anything with the ST, as I'm currently looking into them for lister-st setup.

regards from Crete,
nikos

[ronmar]

Doug,

You are not getting the jist of what I said.  Please read it again.

It is like the Z winding represents your big toe, and you have just stuck it into a calm pool of water.  It causes ripples in the magnetic field by being there. These ripples end up on the output of the alternator, apparently by transformer action. By leaving it completely disconnected, i.e. NOT using it as a source of power for any purpose at all, it is the same as unwinding it from the alternator frame and selling it to the scrap man.  It is not there to induce ripples in the magnetic field.

Hi list,

Jumping in a bit late here, with what might simply be a brain fart.
If the above is assessment wrt induced distortion is correct (I've not seen the Z winding inside an ST), but is it possible to replace the single Z winding with a contra wound pair, in that way to possibly achieve cancelations of of induced fields? Haven't really thought this out yet, but one winding could be connected to a second bridge and also power the field.

Or keep the original winding, and add a second z winding 180 deg. opposite and feed the existing bridge (push-pull anyone?)
One local rewinder here add field windings to replace cooked or NLA avrs, mostly old industrial gensets.... I know it works, albeit I dont know how cleanly the output might be..

I am concerned that some report that they cant really power anything with the ST, as I'm currently looking into them for lister-st setup.

regards from Crete,
nikos

It is probably easier to add filter caps to the rectifyer output to the brushes/field winding.  This cleaned up my ST output considerably,  It made it clean enough for a UPS to accept it and shft to it as the source like it would when connected to commercial power...

[Doug]

I don't know if that would work Niko.....

As I understand it the harmonics are providing the extra current to increase the excitation. As second set of Z coils 180 deg out of phase and seperately rectified might work.

The problem seems to be cleared up with a capacitive filter.

Doug

[jimdunne]

Sorry Doug,
Capacitor filter applications are very limited, and are sometimes used on extremely high-voltage, low-current power supplies for cathode-ray and similar electron tubes, which require very little load current from the supply. The capacitor filter is also used where the power-supply ripple frequency is not critical; this frequency can be relatively high.

This is not at all applicable re: Z windings on ST heads.

Respectfully, Jim

[Doug]

Well Jim I honestly don't know, and won't untill I set about to tinker.

I can only go on my gut feeling that a stiff and steady voltage to the rotor would be better than an unfiltered DC source. Others have done it and if Ronmar says it helps and made a noticeable improvent on the scope so I am inclined to believe him and follow.

Second every 3 phase drive I've ever seen with a DC link uses a lot of heavy capacitive filtering. This isn't particularly high voltage ( ranges from 208-600 ac to 700 vdc in my little corner of the trade ). The IGBTs or SCRz in the inverter section wouldn't be able to anything with the chopy noise without all that capacitance filtering and storred energy in the caps.

But as I stated before electronics is not my strong suit, I like tubes full of mercury and MG sets.....

Doug