How the ITS works is now known.

[simple man]

Originally Posted by JohnnieB

That is the Age and Treachery part of my signature block.

Got the age part down, but I'm afraid I still need schooling on the treachery!

[JohnnieB]

Originally Posted by whizzo

One thing to understand is that a well written pattent, gives enough information to protect the intelelectual property but not enough to make coppying easy or operation understood.

Many patents have intentilnally vague, flawed or misleading information.


What I expect is this. <snip>

As defined by the US Patent Office: "A patent is a property right granted by the Government of the United States of America to an inventor “to exclude others from making, using, offering for sale, or selling the invention throughout the United States or importing the invention into the United States” for a limited time in exchange for public disclosure of the invention when the patent is granted."

However it is true that most patent applications are carefully written to convey a new and novel idea, without disclosing enough of the intellectual property that protection is being sought for, to duplicate it. If not enough information is submitted to prove it is a new and novel idea, the application is reject and must be re-submitted with additional information. Of course, if more information than what is needed is submitted, it cannot be "un-submitted" and is disclosed publicly.

The operation of the ITS sensor is fairly well described in the patent document I posted. Not enough to duplicate it, but well enough to understand how it works.

[JohnnieB]

Originally Posted by gwh1bass

Are we looking at some reverse engineered products coming soon!?!?!

Not that I know of. The goal was to figure out a way to bench test an ITS sensor.

On the other hand, that patent may have already expired.

[JohnnieB]

Originally Posted by simple man

Got the age part down, but I'm afraid I still need schooling on the treachery!

Chicanery may be a better description of the art form used. My treachery is mostly the think outside the box type stuff.

Of course, there have been those that have been on the receiving end that have describe it in far more explicit terms.

[radioman]

Originally Posted by JohnnieB

Did you read the info in the patent documentation that describes how it works?
There is also a schematic in there, showing all the components.

Looks like quiescent current is determined by the applied voltage. It also appears that the plunger moved by the throttle pedal is a critical part of the operation, since they describe it in the patent.

The way I read it, the mechanical sensing range is from 0.05" inside the tunnel to 0.9". Looks like there will be deadspace at both the top-end and bottom-end of the pedal stroke when it is adjusted right.

I tried it with a 1k in seris and could get a voltage reading, probably because the only 9V battery I had that was in use, wasn't very good. Still in the blister pack, but only 8.3V. I ended up just connecting the weak 9V battery through an ammeter without the resistor in series with the battery. I only got 0.55ma, but it went up to 0.87ma when I stuck a screwdriver in the hole.

Looking at the schematic, the input voltage only feeds the three IC's and a voltage divider that is set someplace between 27k and 47k, so connecting a 9V directly to it won't cook it. I'll see if a good 9V battery works better and then see what happens with higher voltage.

Nice to know it draws about 1.5ma at rest in the cart. That is what I'll shoot for on the bench.

The diode bridge input prevents damage from accidental reverse polarity by steering the current regardless if the polarity of applied voltage. A neat application of bridge rectifier arrangement applications other than full wave bridge rectifiers.

[whizzo]

Sorry chaps...gone off a bit half cocked......did not read the pattent document.

Have now.
Quite surprised at the amount of detail given, pretty well full circuit discription.
not particularly clever....I have read other patents and all you get is a broard discription and a block diagramme.

Quite often too the patent for a thing is not for what you would expect.

Anyway...I continue to expect the same issues that would be found in other inductor bassed controlls & things.

mechanical wear in the tubular part where the slug travels in the coil could result in issues.

as for reverse engineering.

With this patent document, no need, next year you could make an exact coppy with impunity unless the patttent owner has some other form of IP pritection.

My understanding is that pattents are issued for 10 years and may be extended for no more than a further 10 years.

As for if you would......if you where intent on bringinmg a product to market.....in this day and age there are other things that would do the job better and would probaly be cheaper to manufacture.

Shaft encoders, hall effect devices, optics and the electronics to operate them have become better and very much cheaper than they where in 1995.

The cost of the electronics would be relativly low, the big cost is the manufacture of the coil and the slug that operates in it.

It could possibly be easy enough to do it all with some sort of micro and off the shelf encoder.

is there are market for a replacement controll for the relativly small number of machines that use this sensor.

Old style pot boxes are still arround and the chineese seem to think it worthwhile making pretyy good coppies......is it viable to make an aftermarket coppy?

cheers

[JohnnieB]

To put a few things into perspective:

Duplicating, cloning, replicating or copying the Curtis ITS sensor is possible, but would the demand for the product justify the expense of doing so?

Everything inside the case is encapsulated in a potting compound, so troubleshooting and/or repairing the PC Board or coil is impractical, if not impossible.

Designing a better sensor using later developments in sensor technology won't be easy since the portions of the ITS circuitry that are in the controller are tailored for the existing sensor technology.

The information in the patent simply answered a few unanswered questions that some of us have had and opened the door to eventually being able to test a sensor without installing it in a cart, but other than that, nothing much has changed.

[yurtle]

Originally Posted by JohnnieB

As defined by the US Patent Office: "A patent is a property right granted by the Government of the United States of America to an inventor “to exclude others from making, using, offering for sale, or selling the invention throughout the United States or importing the invention into the United States” for a limited time in exchange for public disclosure of the invention when the patent is granted."

However it is true that most patent applications are carefully written to convey a new and novel idea, without disclosing enough of the intellectual property that protection is being sought for, to duplicate it. If not enough information is submitted to prove it is a new and novel idea, the application is reject and must be re-submitted with additional information. Of course, if more information than what is needed is submitted, it cannot be "un-submitted" and is disclosed publicly.

However, there are legitimate patents granted for zero point energy and anti-gravity devices. Not all patent application reviewers are properly trained in the sciences.

I have also dug up patent info on devices I've acquired, and find it to generally be useful.

[radioman]

Problem with my old golf cart that started the ITS investigation when it failed to move acted up again today. Yesterday it worked fine. It sat overnight and today it would not move. I used information from previous readings to check the ITS. It has a current draw of 1.3 milliamps and increased to 2 milliamps as throttle was depressed all the way. Under the same conditions the voltage across the ITS measured 12 volts and decreased to 8 volts. I checked everything to the controller ( B+, B-, ITS input, etc, continuity of the F-R switch contacts and wiring to the to the motor terminals. Controller is not producing M-. It might go back to work tomorrow. Temp today 78 degree today might be a contributing factor. But the ITS is not the problem. (JohnnieB: Please note correct current measurement is 1.3 milliamps on solenoid click, not 1.5 ma I reported earlier. I read the red AC graduation scale on my Simpson 260).

[JohnnieB]

Originally Posted by radioman

Problem with my old golf cart that started the ITS investigation when it failed to move acted up again today. Yesterday it worked fine. It sat overnight and today it would not move. I used information from previous readings to check the ITS. It has a current draw of 1.3 milliamps and increased to 2 milliamps as throttle was depressed all the way. Under the same conditions the voltage across the ITS measured 12 volts and decreased to 8 volts. I checked everything to the controller ( B+, B-, ITS input, etc, continuity of the F-R switch contacts and wiring to the to the motor terminals. Controller is not producing M-. It might go back to work tomorrow. Temp today 78 degree today might be a contributing factor. But the ITS is not the problem. (JohnnieB: Please note correct current measurement is 1.3 milliamps on solenoid click, not 1.5 ma I reported earlier. I read the red AC graduation scale on my Simpson 260).

Been there - done that. More than I care to admit.

The voltage is supplied by the controller and if you have a stock (Curtis) controller, the voltage is measured from B- to one side and then B- to the other side. I don't know if those voltage readings are good or bad without knowing the controller type. What controller do you have?

With the pedal pushed just far enough for solenoid to click, you should measure FULL battery pack voltage between B- and M-. If not, there is an open somewhere in the high current circuit.(Cables, F/R switch contacts, solenoid contacts, Motor and battery pack)

At low RPM, the motor will draw all the amps the battery pack will produce and the controller limits the number of amps the motor is allowed to draw. The control element (a dozen or so MOSFTEs in parallel) is located between the B- and M- terminals on the controller. When the MOSFETs are turned off (No throttle input) they drop the entire battery pack voltage. When they are turned on 100% of the time (Max throttle input), they only drop about 0.5V per 100A of current flow through them.