Patent #4,107,619

[lumanauw]

NP's Patent #4,107,619 is said to be "Statis" patent. A good-small amp is driving output loudspeaker with the help of bigger amp to give the current to the load.

Which Statis or Threshold amp schematic uses this Patent? The ones that can be found in this forum seems none incorporating this patent.

Is it the same principle as Current Dumping power amps (Quad, maybe) ?

 

[lumanauw]

I don't understand the fig.2 in this patent.

I redraw this fig.2, and it seems device 59 is forming "Howland Current Pump" with Vc at R7 as the input.

But I'm confused. In my thinking, R4 should be connected to VC (not to ground) and R6 should be connected to ground (not to VC).

The logic is if Vc is positive towards ground, then the device 59 should be giving current, not sucking current. Am I wrong here?

 

[Nelson Pass]

There were only a few amplifiers built that actually corresponded
to the diagrams as shown in the patent. They worked well, but
were simply too complicated. A much simplified series was
introduced as the Stasis 1, 2, and 3. There, a single
complementary pair of followers was connected to the output
stage, but drove current gain off their Collectors "Sziklai" fashion,
and the whole thing was cascoded, so that the followers
experienced near constant current and voltage.

 

[lumanauw]

A much simplified series was introduced as the Stasis 1, 2, and 3.

Why is that I'm not surprised by this. A Nelson Pass can get the same result with much more simpler and elegant way

This schematic is made By Mauropenasa. In this schematic, R6 is the sensing resistor, and the more positive side of the sensing resistor is connected to (+) input of U1.

In the statis patent, R7 is the sensing resistor, and the more positive end of this resistor is is connected to (-) of device 59.

These 2 has opposite operation of the current pump, one gives current for positive sensed voltage, one sucks current for positive sensed voltage?

Which one is the right one?

 

[Nelson Pass]

Hmmmmm...

From a cursory look, I don't think it's the same, but I'll think
about it when I get back from vacation.

/pass/: has been at the beach for a week, and not thinking
too deeply.

 

[lumanauw]

Hi Mr. Pass,

You are accessing this forum from a beach / On vacation.
Beaches and smart brains are compatible.

I would appreciate your answers more this way

 

[lumanauw]

How to use this schematic?

The (-)input of opamp block is to be (-)input of the current pump.
The (+)input of the opamp block is to be (+)input of the current pump.

IF the (+)input is more positive than (-)input, then the output is giving current or sucking current?

 

[angel]

At risk of threadjacking, I would mention that similar benefits have been achieved by means of another patent by Dynamic Precision.

They use a class-B amplifier to drive the ground of a floating power supply that is used for a +/- 15V class-A amplifier. Effective result is 400W or so with class A sound and drive.

Somewhat simpler to do as well.

 

[Cobra2]

Dynamic Precision patent...

Off topic...: I think it's :
United States Patent 6,255,907
(international publication no # WO 98/05119)

Arne K

 

[Nelson Pass]

They use a class-B amplifier to drive the ground of a floating power supply that is used for a +/- 15V class-A amplifier. Effective result is 400W or so with class A sound and drive.

That would be the 1977 patent from Sano et al, #4,115,739

 

[Nelson Pass]

Re: Dynamic Precision patent...

United States Patent 6,255,907

That seems to be the patent # for an air filtration device.

 

[Cobra2]

...the air we breathe...

try this...:
http://patft.uspto.gov/netacgi/nph-...,255,907.WKU.&OS=PN/6,255,907&RS=PN/6,255,907

Arne K

(don't know if it's the right patent, but I've been told that it is held by DP...)

 

[Nelson Pass]

Ah, there it is. I see that they did not reference Sano's
patent, which may explain a lot.

 

[lumanauw]

For me (I'm not too fluent with English), the "Dynamic Precission" patent is 95% the same with Hafler's Transnova patent. It uses complete low voltage amp to drive grounded emitor output stages that modulates the floating supplies and the output is taken from the CT of the floating supply.

The feedforward/Error correction in Transnova patent is implemented as R (Ikorr) in this patent.

 

[Nelson Pass]

I might be wrong, but I haven't seen the schematic and I am
guided by the quote "They use a class-B amplifier to drive the
ground of a floating power supply that is used for a +/- 15V
class-A amplifier"

I don't think that this describes the Transnova (a nice circuit
in its own right) because it describes two amplifier stages,
a large one driving the supply of a small one. The only topology
I know that fits is Sano et al, which was made by Panasonic.

You might be amused to know that Sano's patent inspired me to
reverse the roles of current and voltage and write patent
#5,343,166

 

[lumanauw]

Hi, Mr. Pass,

Yes, you are right. If only follows the quote (without reading the patent itself) the quote will be similiar to Sano's patent.

But after I read the schematic in Dynamic Precission patent, I think it is more similiar to the Transnova more than to Sano's.

BTW, what happened to your patent #5,343,166? You said you "wanted to save it for the old days".

I always amazed by what you built/draw. When will you make something with this patent #5,343,166? From 7 patents of yours, (from the power amp categories) I think this one have the least implementation.

 

[Nelson Pass]

I have never had occasion to put it in a product.

 

[angel]

The description of the circuit is accurate. I read a reverse-engineering bit on the product based on it somewhere.

The damn thing (DP A1) has more parts than a high-end class D amplifier, oddly enough, more transformers and capacitors than you'd expect if it were pure class A (2x800W @ 4ohm), and a very nice sound. Who says opamps have no place in high-end circuits?