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rdaveolivaw
07 February 2009 @ 11:52 am
No smoke,fried controller, dead power supply, or any other bad thing happened.
The motor accelerated, held a set speed, then decelerated to a stop as expected.
Not bad for my first servo controller. Now that the hardware has been proved to work, and the concept of moving a heavy device without ripping it apart or killing someone has been proven viable,the fun begins.

I now have to figure out an efficient way to do this simultaneously for 2 doors, with completely different motion characteristics, using a total of 24 bytes of temporary memory and 16k of program memory.

Here's how to make a motor behave nicely (in Pbasic):
It's almost in english. The only strange part might be the "nest" section, which is needed because my door end travel sensors don't stay on when the door reaches it's final position when closing.


move_door:
acceleration CON 70 'rate of acceleration
deceleration CON 30 'rate of deceleration
maxspeed CON 80 'max door power applied
start_torque CON 20 'initial motor current
open_delay CON 100 'movement after flag is seen
flag_speed CON 10 'speed after flag seen
close_delay CON 0 'movement after close flag
door CON 1 'which door is operated
direction CON 1 'open or close
max_time CON 500 'max time allowed to complete move


accel:
'set direction relay
FOR x=start_torque TO maxspeed 'accelerate to max speed
'if hit estop
PWM 13,x,acceleration
NEXT
move:
PWM 13,maxspeed,50 'maintain speed
'if hit estop 'stop of door is jammed
'if flag then nest
'increment timer,if exceeds max then estop 'protect against electrical failure
IF wtcdg=1 THEN move 'simulate the door flag for testing
nest:
FOR x=maxspeed TO flag_speed 'decel to flag speed
PWM 13,x,deceleration
'if hit estop
NEXT
FOR x=close_delay TO 0 'move slow to door stop
PWM flag_speed,50
NEXT
decel:
FOR x=flag_speed TO 0 'decelerate to zero
PWM 13,x,deceleration

NEXT
'reset direction relay
'store door position in memory
 
 
rdaveolivaw
05 February 2009 @ 07:07 pm
The human condition is in the end based on the stupid assumptions of brilliant people.

Something Cody did a while back made me consider this:
He bought an electrolysis bottle for his car.  This device takes water and with electricity, spits it into it's component parts, oxygen and hydrogen. These gases are then sucked into the engine intake where they enhance the fuel air mixture and increase horsepower.  This is a great idea, and most people would wonder why this isn't a standard feature in car.  Where I got involved, was that the top of the bottle where the wires were hooked up was getting really hot, and actually melting the top.  Obviously, that much heat with explosive gases inside the bottle can't be a good thing.  Instead of fixing the bottle, I elected to tell him why this really wasn't going to work. (Anyone have a clue?)  The reason has to do with why you don't see hydrogen gas stations all over the place- it takes a lot of electricity to split water into gas, and the very best rigs can only get out about 30% of the energy put  into splitting the water. In the case of the engine mounted bottle, it was maybe adding a few horsepower to the output of the engine, but the alternator was creating a huge load to spit the water in the first place, resulting in a net loss of output power.

Now for another scenario:
Fly a ship with gyroscopic discs  into space conventionally. The discs would be set in pairs, and the pairs set perpendicular to each other  Power it with a nuclear generator, then, with electric motors accelerate the discs in opposite directions, to a high speed.  At this point they generating cetripetal force.  If I now take a second electric motor, powered by the same generator and rotate one pair of discs perpendicular to their spinning axis, I should get thrust at right angles to the rotation of the disk, and my ship should start moving.  The cool thing about this is there would be no obvious source of thrust when viewed from the outside, (other than the radioactive waste coming off the nuk generator!)  
There must be something very obviously wrong with my ship design, but I don't have a clue what it would be, just as Cody missed the power issue with his electrolysis bottle on his car.

Centripetal force might be really fun to play with.  I wonder if anyone has taken a disc, spun it ridiculously fast and observed any artifacts of generating that much fake energy in one place. Are there centripetal Eddy currents?

I absolutely have no intention to learn enough math to figure this out on paper, but spinning shit really fast sounds like a lot of fun.......
 
 
Current Mood: contemplativecontemplative
 
 
rdaveolivaw
04 July 2007 @ 12:19 am
On one of our trips around town on the 'wing, Kim noticed a couple of jet skis for sale.   We thought it would be rather fun to get some, so she went back to  get information, but couldn't remember which street they were on.  A couple days later, we saw them again, and eventually went back to get the info.  I, apparently being a guy and all, contacted the owners and made an offer on them, which they accepted.  At this point, Kim was surprised that I considered purchasing jet skis.  She thought that I would not pursue an inquiry on them, even though she started this mess in the first place. From my point of view, if she shows any interest in any gizmo which goes fast if you put enough gas into it, I'm pretty much going to get it- regardless of how impractical it actually is.
Anyway, the result of all this is that I'm the proud owner of 2 jet skis. One is large enough to carry three at a very respectable rate of speed, the other is capable of moving a person over water at a ridiculous rate of speed (almost 70mph).

I did learn another very important piece of information concerning jet skis- anyone with an anus or vagina could become severely injured if they get in the way of the water exhaust on the ski.  The label on the side of the ski makes this very clear.  Women need to be especially careful as they have more opportunities to screw up.  I personally believe that having my balls blasted by high velocity water would tend to cause severe injury as well, but it's not on the label, so apparently it's not a problem. I do feel for the guy that had to prove this out in field trials........
 
 
Current Mood: deviousdevious
Current Music: boundzound-louder
 
 
rdaveolivaw
30 June 2007 @ 11:01 am
Zack  
Apparently, Zack learned that Kelly was considering taking him to Seattle, and decided to run away from home in protest.  I guess if you look at this in another perspective, he may have left the house to prove he had the stamina to take the trip to Seattle.  Use which ever explanation suits your sense of Zackness.  To make matters worse, it took us 3 days to figure out that he was missing.  I suppose this isn't as bad as it sounds- Zack runs in bipolar cycles of continuous need for attention and total indifference to anything alive.  That coupled with my travel, Kim's preoccupation with work and medical issues, and Cody's complete obliviousness to anything not related to his car, work, or computer.

In any case, I fed him Monday and had the vague thought that it was interesting that the food bowl was empty and Zack wasn't yowling in protest.  Being a vague thought, it happily went on its way into oblivion.

In any case, Kim finally figured out we didn't have a cat when she was scheduling an annual vet appointment for him and realized she hadn't seen him in a couple days.  A search was started to no avail. The only conclusion that could be made was that Zack had gotten out, and was lost injured or dead.  This is the only good conclusion we could arrive to at the time, since Zack has never been away from his food bowl for more than 2 hours in his entire life, and as his weight attests, this would be a totally unacceptable scenario.

I got home the night Kim found him missing, and pretty much looked (and sniffed!) in the same places Kim did, with the same result- no cat.
I looked around the next day with no luck.  At this point I turned off the cat's water bowl, and gave him up for gone.  Even Kim was preparing to pack up the cat stuff in resignation of his departure.
I was bothered about the whole situation.  Not so much that Zack was gone, but that we didn't have a clue as to how or what happened to him.
I had that feeling that something in life was out of kilter in a bad sort of way, and that I was powerless to do anything about it.

At that point, Zack shows up under the deck meekly meowing because he can't figure out how to get out of the lattice I put up last weekend.  We did look for him under the deck before, but he wasn't there.  My guess is that he got lost, finally figured out where the house was, and crawled under the deck to get some protection from the cruel outdoors. 

He's back, dirtier than before, with a sore right foot, but otherwise none the worse for wear.
I did actually see him drinking this morning, so life is good- for today anyway.
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Current Mood: contemplativecontemplative