Search found 240 matches

by terkio
Sun Nov 22, 2020 7:09 pm
Forum: The Peabody Lounge
Topic: The Corona Virus Hoax of 2020
Replies: 296
Views: 25022

Re: The Corona Virus Hoax of 2020

Where have I seen the story of one who had a positive test in a nostril and a negative in the other one ? :D
by terkio
Sat Nov 21, 2020 8:49 am
Forum: Pro Audio Design
Topic: Super Low Distortion Ultra Pure Audio Oscillators Revisited
Replies: 52
Views: 49240

Re: Super Low Distortion Ultra Pure Audio Oscillators Revisited

I've been able to lower second harmonic distortion by identifying three sources. 1) The VCA. I lowered the input current by 14 dB. It no longer contributes. Is this the VCA from THAT Corp ? Have you figures about the VCA distortions at these low levels. And comments about noise when going to low le...
by terkio
Mon Nov 16, 2020 12:04 am
Forum: Pro Audio Design
Topic: Bipolar Power Supply Load Current Imbalance And Transformer Core Saturation
Replies: 21
Views: 1055

Re: Split Power Supply Load Balancing

From my simulation: Average currents over an exact period. WindingA -463.49mA WindingB 463.49mA Center Tap -926.98mA Loads 10 Ohm and 50 Ohm. 1.2301A and 303.13mA Difference -926.98mA _________________________ Edit. Now, with balanced loads WindingA: 0A WindingB: 0A Center Tap: 0A Loads 10 Ohm and 1...
by terkio
Sun Nov 15, 2020 1:46 pm
Forum: Pro Audio Design
Topic: Bipolar Power Supply Load Current Imbalance And Transformer Core Saturation
Replies: 21
Views: 1055

Re: Split Power Supply Load Balancing

I decided it might be a good idea to point out what I'd found. Yes it is. Your study is far more interesting than efforts I have seen on regulated PSU, aiming at sub microvolt noise, ripple reduction beyond 130 dB and output impedance in micro Ohms. :lol: I'd be curious to find a source that just c...
by terkio
Sun Nov 15, 2020 11:31 am
Forum: Pro Audio Design
Topic: Bipolar Power Supply Load Current Imbalance And Transformer Core Saturation
Replies: 21
Views: 1055

Re: Split Power Supply Load Balancing

At the beginning of this discussion, I was confused, then used simulation to figure out what was going on. 4 diodes, 2x 10000uF caps with ESR 0.5 Ohm. As a transformer 2 AC voltage sources, 18V peak with 1 Ohm resistance. Loads 10 Ohm and 50 Ohm. Then all became clear in my mind. I am aware, this tr...
by terkio
Sat Nov 14, 2020 10:35 pm
Forum: Pro Audio Design
Topic: Bipolar Power Supply Load Current Imbalance And Transformer Core Saturation
Replies: 21
Views: 1055

Re: Split Power Supply Load Balancing

Exactly the waveforms I get with simulations. And no need to insert 1 ohm resistors ;) Actually there is no need for simulations nor measurements to figure that load imbalance induces DC at the CT. The current load difference flows at the ground track at the loads. This current is near pure DC with ...
by terkio
Sat Nov 14, 2020 10:48 am
Forum: Pro Audio Design
Topic: Bipolar Power Supply Load Current Imbalance And Transformer Core Saturation
Replies: 21
Views: 1055

Re: Split Power Supply Load Balancing

Interesting studies, I get similar results calculating with LTSpice simulations. I am thinking we have millions of center tap transformers used in line level audio. Negative and positive rails are rarely equally loaded in those equipments. It seems to me, nobody cares, nor has ever seen trouble, is ...
by terkio
Thu Nov 12, 2020 7:50 pm
Forum: The Peabody Lounge
Topic: Entropy
Replies: 1157
Views: 450359

Re: Entropy

From a familiar story about an old axe. :lol:
When the pan is worn out, you change it, when the handles are worn out, you change them, but that still is the same wheelbarrow.
by terkio
Thu Nov 12, 2020 7:05 am
Forum: Pro Audio Design
Topic: Bipolar Power Supply Load Current Imbalance And Transformer Core Saturation
Replies: 21
Views: 1055

Re: Split Power Supply Load Balancing

The single phase Full wave Center tap ( The middle diagram in the three ) driving one load. The middle diagram of the three (FWCT) IS driving one load and I agree it will not produce DC in the core. But when the negative supply is added there are two loads - the second is not shown in that drawing....
by terkio
Wed Nov 11, 2020 10:56 pm
Forum: Pro Audio Design
Topic: Bipolar Power Supply Load Current Imbalance And Transformer Core Saturation
Replies: 21
Views: 1055

Re: Split Power Supply Load Balancing

The single phase Full wave Center tap ( The middle diagram in the three ) driving one load. It makes no DC at the transformer. If it were, this widely used configuration would heat, the core saturate, eventually blow up. DC and spurious harmonics can occur only from a mismatch in the two rectifying ...