Trackball Optical sensors & RandyT's high resolution encoder wheels

[specfire]

I just purchased 4 TB's from Edgedamage (in the B/S/T forum).  They are all fairly old and 3 of them need to be rebuilt.  They are all HAPP.

One of the trackballs has RandyT's high resolution wheels (intended for 3" Imperial but mounted on a 3" HAPP), however, I am wondering if the optical sensor (being so old) is fast enough to track the much higher frequencies these new wheels would generate.  In other words, are these new wheels on old optical sensors a bad combination?  If so, would new sensors be much faster?  Is there a reason that these would not work on Happ TB's vice Imperial?

RandyT has a disclaimer on his site about slow PC interface controllers, but I am asking about the quality of the small optical sensors mounted on the TB itself.

I don't currently have an encoder to interface them to my PC so I can't test out my questions.

Thanks for any help,

specfire

[NoOne=NBA=]

The only problems I've ever had with varying tooth sizes is that sometimes you have to push or pull the optic sensors a bit to line up better with the teeth.

I learned that one from Oscar.

I can't comment on the Happ optic cards specifically though because I've never tried varying the teeth on them.

[Minwah]

I don't really know the answer either but...

I know Oscar used to use Happ-style encoder wheels on his spinners, and after that he released some custom metal ones with more teeth to improve performance.

I would think it should work fine.

[u_rebelscum]

I am wondering if the optical sensor (being so old) is fast enough to track the much higher frequencies these new wheels would generate.  In other words, are these new wheels on old optical sensors a bad combination?  If so, would new sensors be much faster?  Is there a reason that these would not work on Happ TB's vice Imperial?

RandyT has a disclaimer on his site about slow PC interface controllers, but I am asking about the quality of the small optical sensors mounted on the TB itself.

The sensors are simple phototransistors, and almost positively fine with new wheels. 

The only problems you migh run into are IF:
(a) The sensor spacing and the tooth/gap widths are the same, a multiple there of, or very close to.  The "perfect" design (cough) is x=(n+0.5)*y, where x is the sensor spacing, y is the tooth/gap width (assuming tooth width = gap width), and n is the max number of teeth and gaps that can completely fit between the sensors.  The worst is x=(n+k)*y, where k=0 or very close to 0 or 1.  In this case, both sensors would trigger at the same time (they are supposed to take turns).
(b) The tooth/gap widths are smaller than the sensor's view width.  This sensor wouldn't be able to tell if the wheel is blocking the light or not.
(c) The sensor is not sensitive enough for very quick changes.
(d) The "wave square-er" (usually an inverter chip) is too slow.

The only one you might need to worry about is (a), because (b) isn't true for the not-that-much-thinner teeth/gaps in the new wheel, and both (c) & (D) are not that likely.  It's much more likely the PC interface is the slow spot, unless the circuits on the TB are going flakely (and need to be replaced soon, new wheel or not). 

That said, Happs came out with a new sensor board (the red ones) mostly for the super high speed golden tee trackball spins.  I didn't notice a difference between that one and the prior version, but all I did was play games - no measured testing. 

So, in short, there is the possibility that the new wheel might tip old boards over their limits, but I doubt it.

[Level42]

We're talking light here, and light is a lot faster then everything else. Only thing is the speed of the photocell....My guess is it won't be a problem.

[u_rebelscum]

We're talking light here, and light is a lot faster then everything else. Only thing is the speed of the photocell....

No, we're talking about the speed of the electrons & electronics.  As you just stated, light is not the bottleneck, so we can almost ignore that.  We have to look at the speed of the phototransistors and de-bouncer or other IC chips (if any) on the TB board.

My guess is it won't be a problem.

I agree.

[RandyT]

Urebel is pretty much correct on this one. 

If the trackball has a built in computer interface (Ie. you can plug it straight into the PC via the USB or PS/2 port) it's a bit of gamble.  Some trackball interfaces, not the optical sensors, may not be quick enough to catch every pulse.  And when the pulses are faster than the interface can count them, things get confused and problems like backspin and jumpy cursors start happening.

In short, I designed these specifically for the Betson with the PS/2 interface and they work great with it.  They will probably be ok with the HAPP variety, as well as any other trackball they physically fit in.  But, if they don't work, it'll most likely be the fault of the electronics receiving the pulses, not the ones generating them.

RandyT

[specfire]

Wow, thank you for such thorough replies. 

I have examined my TB's more closely and they are Atari, not Happ, so are likely 20+ years old.  (AFAIK Happ uses the Atari design and so the TB's should be physically the same.)  u_rebelscum, is there any reason I should be concerned about 20+ year old Atari phototransistors?

Another question, can anyone identify the parts circled in red from the exploded view image below of a 3" Happ TB?  My Atari TB's don't have these parts.

Thanks again for all the help.

[specfire]

Bump.  Can anyone identify the parts circled in red?

[u_rebelscum]

Bump.  Can anyone identify the parts circled in red?

If you look it up by part number (95-0555-140), it's copper foil, at least the bottom two.  Those are "anti-static" stuff, electrically connecting the metal rollers to the metal screws holding the case together.  The screws are grounded through the green wires (part# 95-0577-00) to some external ground.  Many BYOAC people here don't hook it up, but others do.  If you live in a dry area with a carpet, you might want to hook 'em up, otherwise ehh [shrug].

I'm not sure what the top two are, unless they're some more of the same?

[specfire]

u_rebel, you are a fantastic contributor to this board.  thank you very much for the help.  I didn't know that you could check by part number on Happ's website until you mentioned it. 

BTW, it would seem that my Atari optic boards are perhaps defective after all so it doesn't matter whether they could operate with RandyT's wheels.