Russ' Phase Linear 700B Going Fully Comp!!!!!!!

[Gepetto]

Ok, on channel 1 I have AC coupling, 20mhz limiting ON..

Did you load the Natl Intruments TEKVisa so you can capture the traces?

 

[laatsch55]

Could it not just be a weaker transformer then what your accustomed to seeing in these?

Ron, that would be for Joe to answer, but unloaded voltage shows 104, so that generally translates to almost 500 a channel.

 

[laatsch55]

Did you load the Natl Intruments TEKVisa so you can capture the traces?

uh.......no......

 

[laatsch55]

So what we are seeing is the AC ripple coming off the caps??

 

[Gepetto]

So what we are seeing is the AC ripple coming off the caps??

Yes
If the minimum valleys sink like a lead balloon between charging pulses you have suspect caps. If the minimum valleys stay reasonable as you load it up then you have either a transformer load regulation problem (winding wire too small) or a bridge problem.

 

[Gepetto]

Yes
If the minimum valleys sink like a lead balloon between charging pulses you have suspect caps. If the minimum valleys stay reasonable as you load it up then you have either a transformer load regulation problem (winding wire too small) or a bridge problem.

BTW, the "minimum valley voltage" is the low point in the yellow trace if that industry term is not familiar to you.

 

[laatsch55]

No Joe it was not familiar to me. I'll hiik things up and get er loaded and see....Had to remotely diagnose a friends PL 400 problem over the phone. Back to the 700 now.

 

[laatsch55]

Ok, the scale of the ripple changes as I load it more but the basic SHAPE of the ripple remains consistent.

 

[laatsch55]

Lika so....

 

[Gepetto]

No Joe it was not familiar to me. I'll hiik things up and get er loaded and see....Had to remotely diagnose a friends PL 400 problem over the phone. Back to the 700 now.

That is always a challenge Lee

 

[laatsch55]

Especially when they can hear something out of that speaker but NOT nothing, rail fuse...

 

[laatsch55]

I think Jer was right, sure seems like a bad BR, cause I've had a nusiance blowing of a rail fuse, now I have no output on one channel and I believe it's a pico this time... The rail fuse went on power up..

 

[Gepetto]

Lika so....

With 22KuF and ~1000W total load you should see about 1.88V droop in between charge peaks. You are close so it is not the caps Lee.

 

[laatsch55]

That's what I figured too. Solen in Canada screwed up my order on the crosover caps. They sent 8.2uf instead of 2.2uf so I have to get that project off the bench. I also have no crossover in the left channel K, and that's causing some tediousness in the house, so I'll get that out of the way and get on swapping out the BR. That's such a pain in the ...

 

[Gepetto]

That's what I figured too. Solen in Canada screwed up my order on the crosover caps. They sent 8.2uf instead of 2.2uf so I have to get that project off the bench. I also have no crossover in the left channel K, and that's causing some tediousness in the house, so I'll get that out of the way and get on swapping out the BR. That's such a pain in the ...

Is that the crossover you took out to use as a model Lee?

 

[laatsch55]

Yes Joe...

 

[laatsch55]

New 35 amp BR now in. Still have an issue with the left channel , DC is bouncing around fro 11mv to 300mv...

 

[laatsch55]

Reinstalled D9, offset is now steady at .008. right side at .011 Back on the AP...

 

[laatsch55]

Max output now a respectable 505 a side...

 

[Gepetto]

Max output now a respectable 505 a side...

That's a s$%^ load of power Lee...