PRaT - please explain

[Barry]

Mary however patented the rheostat, securing her as the recognized inventor patent 1,357,773 Application filed Dec 12 1919, and patented Nov 2 1920
https://patents.google.com/patent/US1357773A/en

Another patent that of Thomas Edison 131,334 differed, called a rheotome it used negative current and is described here as a switch for telegraph equipment
http://www.edisonmuckers.org/wp-cont...6/00131334.pdf

The point being the device was never designed to pass audio signals, rather - one could argue heavily borrowed, but not in sympathy with the actual requirements of audio circuits.
Hence we find 90 years later: https://www.pinkfishmedia.net/forum/...tortion.68076/

Greenewalt's patent was for a rheostat/potentiometer having a non-linear law, it was not for the rheostat per se, the latter of which having been in the public domain cannot be patented.

[Light Dependant Resistor]

Greenewalt's patent was for a rheostat/potentiometer having a non-linear law, it was not for the rheostat per se, the latter of which having been in the public domain cannot be patented.

Sorry Barry but her patent was clearly for the rheostat. here's an excerpt of the patent text. https://patents.google.com/patent/US1357773A/en

M. H. GREENEWALT.

RHEOSTAT.

APPLICATION FILED 05c. 10, 1919.

1,357,773. Patented Nov. 2, 1920.

2 SHEETSSHEET 2- UNITED STATES PATENT OFFICE.

RHEOSTAT.

Specification of Letters Patent.

PatentedNov. 2, 1920.

Application filed December 10, 1919. Serial No. 343,826.

To all whom it may concern Be it known that I, MARY HALLOCK GnnnNnwALr, a citizen of the United States, residing in Philadelphia,Pennsylvania, have invented Rheostats, of which the following is a specification.

It has been found that forv a light capable of giving forth thirty two thousand six hundred and ninety seven milli-lamberts of brightness as many as two hundred and sixty seven perceptible gradations, and in a light having a capacity of nine hundred and eighty seven and ninety four hundredth milli-lamberts of brightness, as many as eighty-six perceptible gradations in the full intensity of the lightemitted, may be produced by properly varying the intensity of said light from that value existing when the lamp is operated at its rated capacity or full candle power, to that value which is just sufiicient to cause it to pass from a condition ofabs olute darkness to one in which it begins to give forth light; and my invention is to provide means especially designed to vary the brightness of a lamp or the light it gives forth by amounts capable of causing the minimum perceptible variations in the intensity of such light between the limits of operation above-noted.

The invention further contemplates a rheostat including a resistance element of that form and construction which shall primarily accomplish the above ends; be compact and substantial of a commercially practicable design; relatively simple as regards the aggregate number and arrangement of its parts, and at the same time include a series of contact blocks and a movable contact member adapted for operation by human, mechanical or automatic power.

It is also desired to provide novel means for portably or permanently mounting a resistance element and its movable contact, together with a convenient mechanism whereby said contact may be actuated by the movement of any suitable part of an operators body to vary the current flow in a light circuit, in such manner that the intensity of a lamp connected in such circuit shall be caused to vary by the least perceptible increments, between the limits of its full candle power and absolute darkness; the invention further contemplating the provision of means for indicating to the operator the relative intensity of the light emitted from the lamp when the movable one object of contact member occupies any particular position.

Another object of my invention is to provide a novel foot operated mechanism for actuating the. movable contact or slider of a rheostat primarily designed to vary the current in a light circuit, in such a manner that the intensity of the light emitted by a lamp in said circuit may be increased or decreased at will by the least perceptible increments, in the manner required, or in obedience to a light score such as forms the subject of my invention set forth in patent application Serial No. 318,393, filed August 18, 1919.

[Barry]

I disagree, the patent covers the use of an optically controlled rheostat, or the use of a foot operated rheostat to control the brightness of a lamp.


One cannot retrospectively patent an idea which is already in the public domain: rheostats have been around since c. 1843 and were obviously in use long before 1919.

[Pharos]

Well this really must be sorted out, the whole of mankind's future depends on it.

[Light Dependant Resistor]

Well this really must be sorted out, the whole of mankind's future depends on it.

Its actually quite interesting, Mary as i gather successfully defended the rheostat patent against some true giants of industry. i have her patent book here, she had 11 patents, but there is extensive history about her.
I will spend some time following her defence of her rheostat patent, and create a thread about it.

... and we can follow the potentiometer today is the direct descendant, see historical references at the foot of the article. http://taggedwiki.zubiaga.org/new_co...bf55874ac1ca12

As I said, it was never designed for audio purpose to pass audio signals at all, and ironically was intended to vary resistance to alter light intensity for her visual music called Nourathar .
Interesting to reflect upon The LDR does the exact opposite using variation of light intensity to vary resistance.... just as all volume controls should

[Pharos]

I meant no offence, but the politics is interesting, and also parallel to the lady who developed the sapphire stylus, and was ripped off by two corporations - cannot recall her name.

[Mr. C]

Once a PRaT always a PRaT

Careful Adrian a lot of Salisbury worshipers will be on the defensive.

Anyhow, back to PRaT its very simple.

The Musicians themselves control PRaT if you like, they alone control the speed, intensity, pitch, loudness and rhythmic content long before any mixing engineer gets his grubby mits on the sliders

Think of a busker playing a tune on the street, both the so called big two PRaT purveyors have are almost an oxymoron as some of the most rhythmically satisfying engaging music has certainly not emanated from either Salisbury or Glasgow.

[anthonyTD]

The Musicians themselves control PRaT if you like, they alone control the speed, intensity, pitch, loudness and rhythmic content long before any mixing engineer gets his grubby mits on the sliders

[walpurgis]

The Musicians themselves control PRaT if you like, they alone control the speed, intensity, pitch, loudness and rhythmic content long before any mixing engineer gets his grubby mits on the sliders

One only has to listen to the Portsmouth Sinfonia to hear that this is true .

https://www.youtube.com/watch?v=hpJ6...t_radio=1&t=32

[anthonyTD]

Aye, plenty of prat going on there, made me laugh hearing that again,

One only has to listen to the Portsmouth Sinfonia to hear that this is true .

https://www.youtube.com/watch?v=hpJ6...t_radio=1&t=32