Quote:
Originally Posted by Steve C
And to think that a mercurey switch in the wire to the coil could have prevented a death at a cost of about $20 just tears me up.........
I think maybe I need to get into the safety business.....
Quote:
Originally Posted by Soundguy
Naa.. wouldn't have done anything... it would have constantly been opening making hte tractor buck and after 2 hrs of running the machine after you bought it, the switch would have been out of circuit on 99.99999999999999999999% of machines sold.
tractors are rough use machines.. that merc switch would have played havoc on anything but smooth pavement..
SPYDERLK said:
I disagree with that %. Ever heard of debounce ?
Quote:
Originally Posted by JB4310
Good intention but don't think a standard merc switch would work, maybe a modified one that wouldn't give false trips. Yes!
You might be on to something though, we've got safety switches for everything else. if you could come up with a cut out mechanism to prevent roll over you'd be a hero, save lives and make a bunch of money. Especially if it was simple enough to retrofit older equipment.
Ironically one of those flippin little safety devices almost cost me my life, took my little outboard motor boat for a cruise on the CT river, as soon as I got out in the current the motor cut out and I couldn't get it to restart. the swift current was pulling me at it's will right for a bridge abutment. luckily another boater spotted me in trouble and towed me to safety. Turned out to be bad merc switch, designed to prevent motor from running/starting when tipped up.
Quote:
Originally Posted by Soundguy
yep.. and if you use a capacitor to prevent false triggers, then you make it were it takes longer to trigger.. and with that.. it's useless.. as you can be tipped in a second or so.
I've also seen safety switches strand people in funny places.
we all are equipped with a very high tech safety device.. it sets on our shoulders and holds our hats up... sadly.. some people don't always use them... hard to replace that with a safety cutout switch...
soundguy
SPYDERLK said:
Ah-h. You just invented it!.... Now tune the trigger in the millisec range. Its called electronics... and logic.
larry
Quote originally posted by Soundguy:
You use some electronics terms but have little practicle knowledge for application it seems.
sure.. you can compenste the swit.. and by doing so you increase the time it takes for the merc shict to appear open. given the very quick time it takes a tractor to go over.. you have just encountered a problem in your logic.. er.. lack of logic. ie.. to properly compensat the switch so bumpy ground doesn't cause periodic cutouts, .. you will need to compensate it for a period longer than it could take for a backflip to occur. not very helpfull.. imagine a car airbag that deployed seconds after a car accident .. or seatbelt locks that only locke dup seconds after the car stopped in the crash.. your debounce idea is novel.. but to make it workable, also nixes the idea for practicality sake... ie.. tuning the trigger in the MS range will not prevent cutouts over rough teraine.. tuning it longer will.. but then the longer delay will allow the rollover.
besides.. only would work on an ignition that needs power.. like spark or fuel solenoid cutoff.. the lage on either of those would make it useless...
soundguy
Quote originally posted by JB 4310:
Only problem most of OUR tractors don't have coils, though the new diesels are all electronic, so you could still do it electronically.
Have to have some type of mechanical fuel cut off for the straight mechanical diesels, That would be more involved and maybe to slow to prevent a back flip.
Even on the gas powered with a ignition cut out, there still might be enough rotating mass in the engine, it wouldn't be a dead stop of movement, just turning off the spark.
As simple as the concept I doubt something truly effective/foolproof can be invented in the basement.
The engineers working with all the options in the E-hydro machines could probably come up with something that could shut down/reverse the drive-train in a nano second, if they wanted to.
All solveable. While real, all these things dont even come close to being daunting. Not a $20 fix tho... even in mass production. It surely could be done in a basement. I know someone capable of doing it. Unfortunately his interests are elsewhere.
larry
correct.. there isn't a 5$ fix to this issue.. or it would have already been implemented. the speed at which a backflip[ can happen is going to make an ignition interlock dubious at best.. perhaps some sort of latching pinion clutch that operated at lightspeed after a certain angle was reached, but with anti falsing sensors so it didn't kil the drivetrain when you simply drove up a hill. I'm sure we could laod down a farm tractor with enough electronics to make it a jet fighter and then it would probably work as designed... the 35million price tag might make it a lil hard for farmers though.. sorry spyder.. no 5$ fix here..
soundguy
Quote:
Current Spyderlk
Youre getting a + on your negativeness, but you simply must develop your negativeness better. Exaggeration and inaccurate quoting is not enuf. You must be more negatively creative. Assume the designer flails thru a morass in a direction of intent, but devoid of thot and oblivious of clues to ease passage and improve results. In a clear frame of mind you would want neither that designer nor yourself working for you.
Conceiving good function with a mercury switch is not that difficult. You just dont restrict yourself to that device alone. You will need sensors and a microprocessor. You sense, at minimum. the front wheels leaving the ground and change of state of the Hg switch. The microP times and correlates the sensed events and acts according to programming - cutting fuel, applying brakes when the sensing composite indicates imminent backtip. Even this simple the system would not be much of a nuisance, so the
"push and hold to override" button would be seldom used. Much smarter components exist in microchip form to supplant the elegant but crude Hg switch. Tractor attitude and roll could be monitored very close to real time. The microP would just have to be real busy to assess inertial transients accurately
[a debounce type of function
] to prevent false alarms. But then, tractor events developing over
hundreds of milliseconds are eons to electronics running at a rate in the megaHz. - You might even get to forget where the override button is.
larry
