Przem's Phase Linear 700 Series II White Oak Conversion

[laatsch55]

Thanks guys...just a file and some timer
...gotta do lawn wars here in a bit and then tomorrow get the truck and trailer ready tomorrow for the river Monday.

 

[pennysdad]

Looks like a bought one.
great work.

... and I'm off to bed. L8r.

 

[derek92994]

Thanks guys...just a file and some timer
...gotta do lawn wars here in a bit and then tomorrow get the truck and trailer ready tomorrow for the river Monday.

Looks like a bought one.
great work.

... and I'm off to bed. L8r.

Be safe Lee, and night night George.

 

[laatsch55]

Joe, with Przem needind a fan outlet, and the available oulet being the old AC mains in hole, I'm gonna have to go past all that low end input section. Is it best to go with 2 conductor and twist it, or go with a shielded pair?? And what do I do with the shield...?? I'm gonna tap 120 off the PRIMARY and run it. It is configured for 240 mains. When rinning the fan and essentially having a lot of unbalanced voltage returning through the neutral what effect will that have?

 

[Gepetto]

Joe, with Przem needind a fan outlet, and the available oulet being the old AC mains in hole, I'm gonna have to go past all that low end input section. Is it best to go with 2 conductor and twist it, or go with a shielded pair?? And what do I do with the shield...?? I'm gonna tap 120 off the PRIMARY and run it. It is configured for 240 mains. When rinning the fan and essentially having a lot of unbalanced voltage returning through the neutral what effect will that have?

I would use the shielded pair and tie the shield to the chassis ground at both the start and finish of the shielded wire run.

 

[laatsch55]

That's what I was looking for, thank you!!

 

[pennysdad]

I would use the shielded pair and tie the shield to the chassis ground at both the start and finish of the shielded wire run.

if that doesn't work, as an alternative, could u run a really really small torroidal mounted in the shroud of the fan.
it wouldn't have to be very big as the current draw would be minimal, and the x-former would isolate any line noise generated by the fans.
just thinking out loud again…. but…. i just thought i'd throw it out there so u guys can jump all over me…

 

[laatsch55]

Why would we do that?

 

[premiumplus]

The fan voltage will be 120 volts.

if that doesn't work, as an alternative, could u run a really really small torroidal mounted in the shroud of the fan.
it wouldn't have to be very big as the current draw would be minimal, and the x-former would isolate any line noise generated by the fans.
just thinking out loud again…. but…. i just thought i'd throw it out there so u guys can jump all over me…

Looking at the schematic for the power transformer, we can assume that the secondary voltages don't change when the amp is configured for either primary voltage. That makes sense, because the amp needs about +/- 100 VDC on the rails and that voltage has to be the same whether we run 120 or 240 VAC sources. It can't be or the amp would go up in smoke. So the voltage at the fan outlet should also remain 120 VAC.

 

[laatsch55]

Yep, the question was whether the unbalanced voltage from the fan usage would trash the neutral circuit....

 

[laatsch55]

I work with 3 phase mostly, just wondering if the same phenomenon is present here.When you take 3 phase 480 say, and single phase some 120 out of a couple legs your ground current goes up , does that happen here?

 

[pennysdad]

Why would we do that?

to stop screwing with the neutral....

 

[laatsch55]

NO....to jump all over you...

 

[pennysdad]

NO....to jump all over you...

in case i was saying something silly..... by suggesting transformer isolation of the fan from the mains.

 

[laatsch55]

In essence, that was my question...

 

[laatsch55]

But, if ya think about it, the 120 is coming off the primary so the secondaries are transformer isolated.....

 

[pennysdad]

But, if ya think about it, the 120 is coming off the primary so the secondaries are transformer isolated.....

yep... wasn't thinking, as usual.

 

[premiumplus]

Yep, the question was whether the unbalanced voltage from the fan usage would trash the neutral circuit....

Not in this particular case...you can put a scope on it to verify but I think you'll be okay.

 

[premiumplus]

But, if ya think about it, the 120 is coming off the primary so the secondaries are transformer isolated.....

One thing to remember is that a transformer will pass certain AC junk along with a pure sine wave. It won't filter noise from AC mains. If it's a step-down transformer it will step down any noise too, but the noise will pass through. Any change in voltage on the primary is reflected into the secondary at the level dictated by the turns ratio of the primary to secondary.

 

[laatsch55]

With the 120 coming off 1/2 the primary windings wont the junk be out of phase with the secondaries?