Star Wars Hotseat Tech Question

RLEVIN

Permanently Banned. Buyer Beware. Questionable bus
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Well, I seem to have most of the simulator up and running now. The interface between logic set and motors is working fine save for one thing:

The motor control board starts off with a LM339 comparator reading the voltage levels from the pitch and roll 5K pots, comparing them against a similar trim arrangement feeding off of +5V and ground through another set of 5K trim pots. Same lines as goes through the logic set to the ADC at position 9K.

The pots that were in the Hot Seat's control panel had worn wipers, reading sporadically from 5 Ohms to 15MEG Ohms, and while waiting for the heavy-duty pots from HAPP I've got a set of $3 Radio Shack audio trimmers in there while I test out the simulator. I'm down to zeroing out the pots and setting the voltage levels on the comparator, but I'm not seeing much variance in the voltage.

I'm about to start adjusting the pots for the boards, but in the meantime I'm wondering if anyone is familiar enough with the por circuits that they might know the range of voltages I can expect from there.

And yes - there will be photos ande vids when it's together...
 
I think if I had a machine that rare, I would pick up those repro pots from Ram Controls. As for the pots from the shack, I seem to recall a friend tell me that there is some major difference on a regular potentiometer vs an audio pot. Can't recall at the moment, but I seem to think it is that one outputs in a linear fashion and the other outputs exponentially. But that conversation was a long time ago. I doubt any of that is any help, but best of luck getting it up and running.
 
I know nothing about this circuit, other than...if the schematic calls for linear taper pots, using audio pots is a bad idea. The reason is that an audio pot is not a linear resistance function, but approximates a logrithmic resistance function.
 
RS does sell linear tapers, nor are these to be the permanent replacements (for one thing they're hardly sturdy enough for use in this case). It is a field expedient method of checking the comparator circuits on-the-fly. I appreciate both the situation and that it causes enough concern to generate three specific responses.

The problem with the unwavering voltage across the pot lines turned out to be in the harness. Last owner/tech had used a lot of black wiring, and ended up crossing one of the field grounds to the double-tied logic grounds for the pots. Fixed that easily enough.

I am in the process of cleaning up the wiring and documenting the add-ins required to run the simulator should it prove useful to the few owners left. Body work and reassembly has begun.

Right now I'm playing around with a schematic editor so it'll be readable and easily reproducible...
 
I think the bigger question is, how did Dale's IQ suddenly increase by 150 points???? You sleep at a Holiday Inn Express last night??? :p
 
Maybe he gave his logon id and passworld to an employee/tech.

This doesn't sound like him at all.
 
Maybe he gave his logon id and passworld to an employee/tech.

This doesn't sound like him at all.
Yes - I have my own account now. When I post from home it'll always be under "jaafaman".

At work it usually depends on who was on the keyboard last.

And yes - I'm the tech Dale's been trying to get on-line...

...jaafaman


BTW, you'll usually most often find me on either the nVidia Hardware Forums or eVGA's support forums if any of you are "into" computer graphics or parallel processing...
 
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Man I'm just bustin' your chops. :p

I know just seem like the thing to say. You guys are right about my tech dude is smart, we call him Mr Miyagi because he knows everything. Guy is dead on with these games and a great EM tech.
 
Just to let y'all know -

I found a decent schematic editor that's open source. Learning it now, but one of its shortcomings is its limited library. As you can tell from this screencap,

http://aprr1g.bay.livefilestore.com...iljd3YnAfkdVRRr7EIoEHNxz3BrG2Td1fX/schema.JPG

on top of learning the editor I'm having to vreate circuit equivalents like with the TIP120 in the screencap.

But you're not being forgotten or overlooked. A full set of photos and schematics will be posted, and Dale's anxious to post videos...
 
Hmmm. That looks a lot like Eagle. You might try searching around for some free libraries - ya never know. It's been quite a while since I've used it.


Just to let y'all know -

I found a decent schematic editor that's open source. Learning it now, but one of its shortcomings is its limited library. As you can tell from this screencap,

http://aprr1g.bay.livefilestore.com...iljd3YnAfkdVRRr7EIoEHNxz3BrG2Td1fX/schema.JPG

on top of learning the editor I'm having to vreate circuit equivalents like with the TIP120 in the screencap.

But you're not being forgotten or overlooked. A full set of photos and schematics will be posted, and Dale's anxious to post videos...
 
Well, I seem to have most of the simulator up and running now. The interface between logic set and motors is working fine save for one thing:

The motor control board starts off with a LM339 comparator reading the voltage levels from the pitch and roll 5K pots, comparing them against a similar trim arrangement feeding off of +5V and ground through another set of 5K trim pots. Same lines as goes through the logic set to the ADC at position 9K.

The pots that were in the Hot Seat's control panel had worn wipers, reading sporadically from 5 Ohms to 15MEG Ohms, and while waiting for the heavy-duty pots from HAPP I've got a set of $3 Radio Shack audio trimmers in there while I test out the simulator. I'm down to zeroing out the pots and setting the voltage levels on the comparator, but I'm not seeing much variance in the voltage.

I'm about to start adjusting the pots for the boards, but in the meantime I'm wondering if anyone is familiar enough with the por circuits that they might know the range of voltages I can expect from there.

And yes - there will be photos ande vids when it's together...
Wrong forum!!!! WRONG FORUM!!!!!!!!! WRONG FORUM!!!!!!!!!!!! Must be something in the water down there LOL

http://forums.arcade-museum.com/forumdisplay.php?f=14
 
Hmmm. That looks a lot like Eagle. You might try searching around for some free libraries - ya never know. It's been quite a while since I've used it.
KiCAD with its libraries. Has a layout and PCB generator, too.

Once I get the XP Mode on Win7 worked out I'll probably go back to the 2007 version of AutoCAD...
 
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