Sensors? - CoasterBuzz

Proximity limits only detect a break in a magnetic sensing field... in other words, metal is what sets them off, not just any random object coming near them.

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Is that a Q-bot in your pocket or are you just happy to see me?

Just do a search on eBay. Heck, you can even get push buttons. Just search for "proximity switch" and if you want buttons, I just search for "800t" because that is the catalouge number for AB push buttons and such. It's fun when you buy your friends buttons for Christmas. Rob really liked his e-stop, hehe.

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"If two coaster trains almost hit each other, why is it called a near miss and not a near hit?"

SOB_TOM said:
Well, talking from experience with a robotics club (anyone ever heard of the FIRST robotics league? GO TEAM 554!) those sensors can be very expensive. I know our robot alone last year cost about 50,000 bucks
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SOB crew in twenty 02
111 SOB laps, and wishing the park was still open

TEAM 165 Here!

No, fortunately my remark is not from experience J. I took it from a SNL Harru Carrey Sketch. It just seemed the opportune thing to say at the time.

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"Standing in line to see the show tonight and there's a light on, heavy glow, by the way I tried to say I'd be there."-The Red Hot Chili Peppers

Actually, proximity switches and limit switches are also two different things. Proxes do just what their name implies: detect when an object comes within proximity of them. How close depends on the model of the switch. Typically 30-50 millimeters. Limit switches, on the other hand, are tripped when an object makes actualy physical contact with the sensing device.

Also, there are proximity switches that can detect non-metal objects. These are called capacitive sensors. The metal-detecting proxes are inductive sensors, as they trip using induction.

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Face/Off Crew '99-'00, Top Gun Sup '00, King Cobra/Days of Thunder Sup '01
Beast Sup '02
Wild Thornberry's River Adventure Sup '02

At the park the mechanics and electricians called them proximity limits (detects metal objects) and mechanical limits (the other one you mention; mechanically tripped by an object).

The proximity limits were used to monitor brake counts, as speed sensors (in pairs or alone), as well as determine train positions. The mechanical limits were only used on transfer tracks and transfer pins, to tell the controllers that the tracks and pins themselves were in place to run or transfer trains.

As far as I know, we didn't use the 'other' type of prox limit that can detect non metal objects, so I imagine their use in parks is pretty limited.

Some coasters would use just about every type of sensor: GASM did. It has proximity limits, mechanical limits, and photocells.

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Is that a Q-bot in your pocket or are you just happy to see me?

Ahh, got ya. :)

Yeah, capacitive sensors wouldn't be useful on an amusement ride, as the sensors could be tripped by many things other than the part that was intended to trip it. In fact, even inductive proxes can occasionally be tripped by other things, especially water. I've seen control systems miscount brake fins in the rain all too many times. It can result in annoying alarms. :)

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Face/Off Crew '99-'00, Top Gun Sup '00, King Cobra/Days of Thunder Sup '01
Beast Sup '02
Wild Thornberry's River Adventure Sup '02

And then people wonder why we shut down in the rain. But try explaining that to them--forget it. ;)

I'd rather have one of those chimes from 7-11. "Ding!" ;)

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"If the beats were made of meat then they would have to be me ..." - L.L. Cool J