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bwy wrote:

noahb1110 wrote:My temperature task is nearly instantaneous, it take like half a second.

Are you going to just drop that hint without telling us what it is?

I was thinking the same thing. I think he's trying to tempt us
Could you please share your task idea with us?

How would I be able to use a thermistor for this task? I was thinking making it colder with an ice pack would increase its resistance, but what could that trigger? If anyone has one, where did they get it? I don't really understand what thermistor (how much resistance, etc.) I would need for a standard 6V DC motor. Help?

How are you guys heating your bimetallic coils? I understand you can heat it up with a battery, but how do you cool it down at the right time in your device?

illusionist wrote:How are you guys heating your bimetallic coils? I understand you can heat it up with a battery, but how do you cool it down at the right time in your device?

Wire it up to a battery with a NC switch, and then just push the switch with something. If you get a sensitive bimetallic strip, it only takes a few seconds to cool down.

So if it is the second to last task, the battery will be heating it up the whole time the device is running right? Doesn't that take up a lot of juice from the battery?

illusionist wrote:So if it is the second to last task, the battery will be heating it up the whole time the device is running right? Doesn't that take up a lot of juice from the battery?

Just a reminder, you can't use any electricity after the sand timer task. So unless your device doesn't have a sand timer task, you will have to put the task earlier if you plan to use a battery. I do my temperature task as the second task, to prevent killing my batteries.

Yeah, i realized that, just gave a random example. So if you were using a 6V battery, how long does the battery last? I mean, how many test runs can you do? I think I might put it in early too to save some juice.

illusionist wrote:Yeah, i realized that, just gave a random example. So if you were using a 6V battery, how long does the battery last? I mean, how many test runs can you do? I think I might put it in early too to save some juice.

If you plug it in immediately before you start your run, it only needs to be on for a few seconds. With that duration, a single battery pack could last the rest of the season. But we inevitably forget that it is turned on at times and it all drains in a couple minutes. But overall this year, I have not gone through nearly as many batteries as last year, so it's not too bad.

illusionist wrote:Yeah, i realized that, just gave a random example. So if you were using a 6V battery, how long does the battery last? I mean, how many test runs can you do? I think I might put it in early too to save some juice.

Definitely. Make it your second or third task, if you can. It shouldn't much matter for this year's tasks, though; my guess is everyone has the first eight tasks, which only take four or five seconds (so who cares where you put it), then sand timer for a minute, then balloon release.

Those 6V batteries have a lot of juice. We used one in an electromagnet last year that lasted for 15ish minutes. If you shut it off first thing in your device, you really shouldn't have to replace it until competition. (Note: High school physics departments often buy lots and lots of these batteries. Go mooch.)

Well... I got a meat thermometer, took it apart (or should I say broke it apart), and to my disappointment found that it had a curly bimetallic strip inside. It is about 4 inches long, pretty thin, and curled up like a spring. I'll pass some current through it later, but has anyone else found success with these? Is there any way for me to make use of this thing?
Edit: I ran electricity through it and it started to make smoke... I'm guessing that's a bad thing... Oh, by the way Primate, it was a Acu-rite thermometer.